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- Herausgeber: John Wiley & Sons
- Kategorie: Ratgeber
- Sprache: Englisch
All the info you need to understand your allergies and manage symptoms
Allergy For Dummies is your one-stop source for comprehensive information on the different types of allergies and their triggers, along with tips on allergy management and prevention. Accessible, Dummies-style explanations will help you deal with hay fever, asthma, eczema, drug allergies, food sensitivities, and beyond—for yourself or anyone under your care. Get answers to your allergy-related questions, understand your triggers, and learn what you can do about allergies of all types. Ensure that you're in control and receive the help you need, with this friendly guide.
- Identify what's ailing you by getting tested for allergies and asthma
- Learn to treat food allergies, allergic skin conditions, drug reactions, and insect stings
- Know how to prevent anaphylaxis, and what to do if it occurs
- Understand your treatment options and find resources for additional information
Allergy For Dummies is for the millions of people around the world who suffer from some kind of allergic sensitivity and need a thorough and approachable guide on the topic.
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Seitenzahl: 548
Veröffentlichungsjahr: 2024
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Table of Contents
Cover
Title Page
Copyright
Introduction
About This Book
Foolish Assumptions
Icons Used in This Book
Beyond This Book
Where to Go from Here
Part 1: Getting Started with Allergy Basics
Chapter 1: Knowing What’s Ailing You
Understanding How Allergies Cause Clinical Symptoms
Triggering Allergic Reactions
Managing Allergic Disease Effectively
Previewing Allergic Conditions
Diagnosing and Treating Allergic Disorders: Just the Basics
Chapter 2: Understanding Your Immune System
Protecting Your Health: How Your Immune System Works
Classifying Immune System Components and Disorders
Classifying Abnormal Immune Responses
Developing an Immediate Hypersensitivity
Reaping the Benefits of Immunology
Chapter 3: Dealing With Physician Visits
Preparing for Your First Visit
Following Up: Second and Subsequent Visits
Paying for Your Care
Working Well with Your Physician
Part 2: Knowing Your Nose
Chapter 4: Nosing Around Allergic Rhinitis
Catching Up with Your Runny Nose
Naming the Types of Allergic Rhinitis
Exploring What Makes Noses Run
Getting a Medical Evaluation
Managing Rhinitis
Chapter 5: Avoiding Environmental Allergens
Explaining Why Avoidance Matters
Targeting Allergens in the Home
Allergy-Proofing Your Home
Chapter 6: Treating Your Rhinitis
Getting Familiar with Pharmacology
Blocking Your Histamines: Antihistamines
Decongesting Your Nose
Two for the Nose: Combination Products
Understanding the Advantages of Nasal Sprays
Controlling Symptoms with Cromolyn Sodium
Reducing Mucus with Anticholinergic Sprays
Treating Rhinitis with Leukotriene Modifiers
Keeping an Eye Out for Allergic Conjunctivitis
Chapter 7: Assessing Common Nasal Allergy Complications
Describing Sinusitis
Overcoming Otitis Media
Part 3: Approaching Asthma
Chapter 8: Reviewing Asthma Fundamentals
Understanding Asthma
Identifying Who Gets Asthma and Why
Revealing the Many Facets of Asthma
Diagnosing Asthma
Managing Asthma Effectively
Chapter 9: Recognizing Asthma Triggers
Identifying Asthma Triggers
Reducing Exposure to Inhalant Allergens
Clearing the Air at Home
Minimizing Workplace Exposures
Avoiding Drug and Food Triggers
Managing Other Medical Conditions and Asthma
Chapter 10: Living Well with Asthma
Outlining What a Long-Term Management Plan Includes
Focusing on the Four Levels of Asthma Severity
Following the Stepwise Approach
Assessing Your Lungs
Taking Stock of Your Condition
Understanding Self-Management
Improving Your Quality of Life
Part 4: Understanding Allergic Skin Conditions
Chapter 11: Controlling Atopic Dermatitis
The Itch That Scratches or the Scratch That Itches
Treating Atopic Dermatitis
Chapter 12: Evaluating Contact Dermatitis
Classifying Contact Dermatitis
Understanding Allergic Contact Dermatitis Triggers
Diagnosing Contact Dermatitis
Treating Contact Dermatitis
For the Love of Ivy — Dealing with These Poison Plants
Poison Pointers: Making It Better
Chapter 13: Evaluating Hives and Angioedema
Understanding Hives: Nettlesome Conditions
Getting under Your Skin: Angioedema
Determining the Nature of Your Skin Condition
Diagnosing Hives and Angioedema
Managing Hives: I Can’t Go Out Like This
Part 5: Reviewing Food, Drug, and Insect Allergies
Chapter 14: Diagnosing and Managing Food Allergies
Distinguishing between Food Hypersensitivity and Intolerance
Identifying Different Types of Food Hypersensitivities
Understanding Nonallergic (Non-IgE) Food Hypersensitivities
Focusing On Food Intolerance
Chapter 15: Understanding and Treating Food Allergies
Looking Closer at the Immunology of Food Allergy
Diagnosing Adverse Food Reactions
Avoiding Adverse Food Reactions
Treating Food Allergy
Chapter 16: Diagnosing and Treating Drug Reactions
Understanding Adverse Drug Reactions
Identifying Forms of Drug Hypersensitivities
Understanding Drug Intolerance and Idiosyncrasy
Diagnosing Adverse Drug Reactions
Reducing Adverse Drug Reaction Risks
Chapter 17: Preventing Insect Sting Reactions
Getting the 4-1-1 on Insect Stings
Diagnosing Your Stings
Preventing and Managing Reactions
Part 6: The Part of Tens
Chapter 18: Top Ten List of Allergy Triggers
Pollens
Molds
Dust Mites
Animal Danders
Foods
Medications
Insect Stings
Latex
Nickel
Poison Ivy, Poison Oak, Poison Sumac
Chapter 19: Top Ten Body Organs Affected by Allergies
Eyes
Ears
Nose
Sinus
Throat
Esophagus
Lungs
Stomach
Skin
Lips and Tongue
Anaphylaxis: Many Organs Simultaneously
Index
About the Authors
Advertisement Page
Connect with Dummies
End User License Agreement
List of Tables
Chapter 4
TABLE 4-1 Main Causes of Allergic and Nonallergic Rhinitis
Chapter 5
TABLE 5-1 Ragweed Pollen Count Guidelines
Chapter 6
TABLE 6-1 Second-Generation Prescription (and OTC) Antihistamines
TABLE 6-2 Nasal Corticosteroid Sprays
Chapter 10
TABLE 10-1 Stepwise Approach for Managing Asthma in Adults and Children Older Th...
TABLE 10-2 The Peak-Flow Color Zone System
Chapter 11
TABLE 11-1 Topical Corticosteroid Classes Ranked from Highest Potency (Group 1) ...
List of Illustrations
Chapter 1
FIGURE 1-1: Allergies can affect organs throughout your body.
Chapter 2
FIGURE 2-1: The allergic inflammatory response is a complex process involving m...
Chapter 4
FIGURE 4-1: The two cross-sections show the difference between a healthy nose a...
Chapter 5
FIGURE 5-1: An allergy-proofed bedroom.
FIGURE 5-2: Dust mites are among the most abundant sources of allergic triggers...
Chapter 7
FIGURE 7-1: Your sinuses are actually hollow cavities that surround your nasal ...
FIGURE 7-2: See how the less visible part of your ear is constructed.
Chapter 8
FIGURE 8-1: A normal airway and an airway with asthma. Note the muscle constric...
FIGURE 8-2: A spirometer measures airflow.
Chapter 9
FIGURE 9-1: Common asthma triggers.
FIGURE 9-2: GERD occurs when stomach contents spill over into the esophagus.
Chapter 10
FIGURE 10-1: The steps of asthma severity levels.
FIGURE 10-2: A patient using a peak-flow meter.
Chapter 11
FIGURE 11-1: Eczema can affect many areas of a child’s skin.
Chapter 12
FIGURE 12-1: Common areas and causes of contact dermatitis.
Chapter 17
FIGURE 17-1: These five groups of insects are the ones whose venom most often t...
Guide
Cover
Table of Contents
Title Page
Copyright
Begin Reading
Index
About the Authors
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Allergy For Dummies®
Published by: John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030-5774, www.wiley.com
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Library of Congress Control Number: 2024951718
ISBN: 978-1-394-25668-6 (pbk); ISBN 978-1-394-25670-9 (ebk); ISBN 978-1-394-25669-3 (ebk)
Introduction
“My nose won’t stop running.” “Oh, my aching sinuses.” “I can’t stop coughing.” “My child keeps wheezing.” If you’ve ever uttered words like these, you’re not alone. These types of statements often describe allergies and/or asthma symptoms and are some of the most common medical complaints reported by people in the United States and around the world.
Allergens can cause a wide variety of medical conditions for millions of people all over the planet. These medical conditions can present as a minor annoyance, such as a runny nose; as a serious medical problem — for example, asthma; or even anaphylaxis, which is a potentially life-threatening reaction. Asthma itself affects more than 25 million people in the United States and is the most common chronic childhood disease and is now considered a global epidemic. And, according to the American Academy of Allergy, Asthma and Immunology, allergic rhinitis (hay fever) affects between 10 and 30 percent of the world’s population. Food allergies are also increasing exponentially across the globe and have been reported to affect up to 8 percent of children and 10 percent of adults in the United States.
But enough about facts and figures. We want to talk about you: How are you feeling? Do you (or someone you know) think that feeling unwell is normal just because you have allergies and/or asthma and that the condition can never improve? Unfortunately, many people answer “yes” to this question. However, as we explain throughout this book, the plain, simple, and accurate medical truth is this: When you receive effective, appropriate care from your physician and you’re a motivated participant in managing your allergic condition, you can lead a normal, active, and fulfilling life.
About This Book
We wrote this book to give you sound, up-to-date, practical advice — based on our more than 70 years of combined experience with numerous patients — about dealing with allergies and asthma effectively and appropriately. For that reason, the book is structured so that you can jump to sections that most directly apply to your medical condition. You don’t need to read this book from cover to cover, although we won’t object if you do. (Be careful, though, because when you start reading, you may have a really hard time putting it down!)
This book can also serve as a reference and source of information about the many facets of diagnosing, treating, and managing allergies and asthma. Although you may pick up this book to find out more about one aspect of allergies and asthma, you may realize later that other topics also apply to you or a loved one.
Don’t worry about remembering where related subjects are in the book. We provide ample cross-references in every chapter that remind you where to look for the information you may need within other sections of the chapter you’re currently reading or in other chapters.
The information in this book is designed to empower you as a person with allergies and/or asthma, thus helping you
Set goals for your treatment
Ensure that you receive the most appropriate and effective medical care for your allergic condition
Do your part as a patient by adhering to the treatment plan that you and your physician develop
Foolish Assumptions
We don’t think it’s too foolish to assume that you want substantive, scientifically accurate, relevant information about allergies and asthma, presented in everyday language, without a lot of medical mumbo jumbo. In this book, you find straightforward explanations of important scientific aspects of allergies and asthma and key medical terms. (You also get a chance to work on your Latin and Greek.)
If you’ve chosen to read our book, we know you’re no dummy, so we’re willing to go out on a limb and make some further assumptions about you, dear reader:
You or someone you care about suffers from allergies.
You want to find out more about allergies and asthma as part of improving your medical condition (in consultation with your physician, of course).
You want to feel better.
You really like physicians named Bill.
Icons Used in This Book
You may notice the following icons throughout the margins of the book. They’re intended to catch your attention and alert you to the type of information presented in particular paragraphs. Here’s what they mean:
This icon represents Dr. Berger expressing his opinion.
The Remember icon indicates things you shouldn’t forget because you may find the information useful in the future.
The See Your Doctor icon alerts you to matters that you should discuss with your physician.
To give you as complete a picture as possible, we occasionally get into more complex details of medical science. The Technical Stuff icon lets you know that’s what we’re doing so you can delve into the topic further — or skip it. You don’t have to read these paragraphs to understand the subject at hand. (However, reading the information with these icons may give you a better handle on managing your medical condition, as well as provide some great material for impressing your friends at your next party.)
You can find plenty of helpful information and advice in paragraphs marked with the Tip icon.
A Warning icon advises you about potential problems, such as symptoms you shouldn’t ignore or treatments you may not want to undergo.
Beyond This Book
The online Cheat Sheet at www.dummies.com provides an important list of myths and misconceptions about asthma and allergies, as well as a list of organs that are affected by allergy and asthma patients. We also include a Top Ten List of Common Allergy Triggers. Just search for “Allergy For Dummies Cheat Sheet” for this additional resource you can refer to whenever you need it.
Where to Go from Here
Although you can read this book from cover to cover if you want, we suggest turning to the table of contents and finding the sections that apply to your immediate concern. Then begin reading your way to better management of your allergies. Or you can search the index, find a topic that piques your interest, flip to that chapter, and read to your heart’s content.
Part 1
Getting Started with Allergy Basics
IN THIS PART …
Understand allergic conditions and how they affect your overall health.
Diagnose and treat allergic disorders to improve your quality of life.
Recognize your immune system so you can better understand your allergic condition and work effectively with your physician.
Choose an allergist who can help treat your allergic symptoms and develop a shared decision plan together.
Know what to expect when you see your physician, including the types of examinations, procedures, and treatments that might be prescribed.
Chapter 1
Knowing What’s Ailing You
IN THIS CHAPTER
Introducing allergic ailments
Connecting allergies and other conditions
Defining the spectrum of allergic conditions
Making sense of allergy signs and symptoms
Recognizing life-threatening reactions
Allergy is a descriptive term for a wide variety of hypersensitivity disorders (meaning that you’re excessively sensitive to one or more substances to which most people do not normally react).
Living a healthy, fulfilling life with allergies involves many of the same general diagnostic, treatment, and preventive measures that we explain throughout this book. In fact, the symptoms of seemingly disparate ailments such as allergic rhinitis (hay fever), most cases of asthma, atopic dermatitis (allergic eczema), food allergies, and other allergic conditions basically result from your immune system’s similar, hyperreactive response to otherwise harmless substances that doctors refer to as allergens. This chapter serves as your entry point into the world of allergies.
Understanding How Allergies Cause Clinical Symptoms
The word allergy is the ancient Greek terms for an abnormal response or overreaction. Contrary to popular belief, weak or deficient immune systems don’t cause asthma or allergy ailments. Rather, your body’s defenses work overtime, making your immune system too sensitive to substances that pose a real threat to your well-being. That’s why physicians often use the term hypersensitivity to refer to an allergy.
These are the main points to keep in mind when dealing with allergies:
Allergies aren’t just hay fever. In addition to affecting your nose, sinuses, eyes, and throat (as in typical cases of allergic rhinitis), exposure to allergy triggers can also cause symptoms that involve other organs of your body, including your lungs, skin, and digestive tract.
Figure 1-1
shows all the organs in your body that allergies and asthma can affect.
These ailments aren’t infections or contagious. You don’t catch an allergy. However, as we explain in the section “
Sensitizing your immune system
” later in this chapter, you may inherit a genetic predisposition to develop hypersensitivities that can eventually appear as allergies.
Allergies aren’t like trends or shoe sizes. You don’t really outgrow them. Extensive studies in recent years show that although your ailment can certainly vary in character and severity over your lifetime, it’s an ongoing physical condition that’s most likely always present in some form.
Allergy triggers include allergens such as pollens, animal dander, dust mites, mold spores, various contact allergens, and certain foods, drugs, and venom from stinging insects. (See the section “
Sensitizing your immune system
” later in this chapter for more detailed classifications of these items.)
Clinical reactions can also result from nonallergic triggers that act as irritants, including tobacco smoke, household cleaners, aerosol products, solvents, chemicals, fumes, gases, paints, smoke, and indoor and outdoor air pollution.
Other forms of nonallergic triggers that can be mistaken as allergies are known as
precipitating factors
and include other medical conditions such as rhinitis, sinusitis, gastroesophageal reflux (GERD), and viral infections (colds, flu, COVID); physical stimuli such as exercise or variations in both air temperature and humidity levels; and sensitivities to food additives, such as sulfites, drugs such as beta-blockers (Inderal, Lopressor, Corgard, Timoptic), and aspirin and related over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil, Motrin), ketoprofen (Actron, Orudis), naproxen (Aleve), and newer prescription NSAIDs known as COX-2 inhibitors, such as celecoxib (Celebrex).
Allergies aren’t mutually exclusive conditions. Having one type of hypersensitivity doesn’t prevent you from developing others. You can have multiple sensitivities to different types of allergens, irritants, and precipitating factors. Many researchers (including Dr. Berger) consider allergic disorders a continuum of disease that can appear in many ways, depending on the nature and degree of your sensitivities, as well as your levels of exposure to triggers.
© John Wiley & Sons, Inc.
FIGURE 1-1: Allergies can affect organs throughout your body.
All that sneezes, drips, runs, congests, wheezes, waters, coughs, itches, erupts, or swells isn’t always due to an allergic reaction. That’s why, as we explain in the section “Diagnosing and Treating Your Allergies” later in this chapter, the first step to effectively treating the underlying cause of your symptoms is properly diagnosing your ailment.
Although the majority of people with asthma also have allergies (and allergic rhinitis in most cases), some manifestations of asthma seem to develop without an allergic component. In cases of adult-onset asthma, which often develops in people older than 40 and is less common that child-onset asthma,
atopy
(a genetic tendency toward developing allergic hypersensitivity; see the next section) doesn’t appear to play an important role. Instead, precipitating factors such as sinusitis, GERD, nasal polyps, and sensitivities to aspirin and related NSAIDs are more likely to trigger this condition.
Triggering Allergic Reactions
Your immune system acts as your second line of defense against foreign substances. The main barrier against foreign substances is your largest organ — your skin. (Remember that for your next appearance on Jeopardy! Masters.)
Usually, your immune system protects you against infectious bacteria, viruses, parasites, and other harmful agents by producing antibodies that learn to recognize the invaders and subsequently fend them off without too much fuss. In fact, most of the time, as long as your immune system works well, you may not even know that this constant, ongoing process takes place to ensure your survival and good health.
However, with an allergic condition, your immune system overproduces antibodies against typically harmless or inoffensive substances such as pollens. Atopy (the genetic susceptibility that can predispose your immune system to develop hypersensitivities) is the inherited characteristic that usually determines why some people’s immune systems overreact and mount full-scale assaults when exposed to allergens, while others can ignore or innocuously eliminate those substances.
Here we explain atopy in more detail and describe how your family history may influence your risk of developing an allergic condition.
ALL IN THE ATOPIC FAMILY
Your genetically determined allergic predisposition (atopy) may present itself through different allergic conditions and target organs. This predisposition and a family history of allergies are the strongest predictors that you may develop asthma and/or other allergic conditions such as allergic rhinitis (hay fever), atopic dermatitis (allergic eczema), and food or drug hypersensitivities.
For example, your Uncle Ed may have allergic rhinitis, your sister may suffer from recurrent sinus and ear infections, and Cousin Al may have a childhood history of atopic dermatitis. Some of your especially unlucky relatives may even be “blessed” with a combination of all these allergic conditions, plus asthma, over the course of their lifetimes. (If you want to be the most popular member of your family, buy them a copy of this book.)
A typical atopic family history could consist of a person having atopic dermatitis as an infant, developing common atopic complications such as otitis media (ear infections — see Chapter 7) as a toddler, experiencing noticeable symptoms of allergic rhinitis in later childhood, and then developing asthma as a teenager.
However, an atopic history doesn’t appear to put you at greater risk than the general population for developing allergic contact dermatitis (see Chapter 12) or allergic reactions to insect stings (see Chapter 17). These conditions seem affect nonallergic and allergic people alike, for reasons that we explain in Chapter 2.
Sensitizing your immune system
A complex sensitization process, in which your immune system responds to allergens, causes allergic reactions. Allergens that your immune system may respond to include the following:
Dust mites (see
Chapter 4
).
Pollens from certain grasses, weeds, and trees (see
Chapter 4
).
Mold spores (see
Chapter 4
).
Dander from many animals, including cats, dogs, rabbits, birds, horses, as well as gerbils, guinea pigs, and other pet rodents (see
Chapter 5
).
Foods, including peanuts, sesame, fish, shellfish, and tree nuts (in adults) and milk, eggs, soy and wheat (primarily in children). See
Chapter 15
for more details.
The venom of stinging insects, including honeybees, wasps, yellow jackets, hornets, and fire ants, all of which belong to the
Hymenoptera
order of insects (see
Chapter 17
).
Drugs, including penicillin, and cephalosporins (see
Chapter 16
).
Contact allergens (see
Chapter 12
) such as poison ivy, oak, and sumac, as well as allergenic substances such as latex, nickel, and formaldehyde, which you can find in many everyday items. (See the section “
Allergic contact dermatitis: Touching experiences
” later in this chapter.)
Developing an allergic reaction
If you’re predisposed to developing allergies, here’s how a typical sensitization process and allergic reaction can develop, using ragweed pollen, one of the most common triggers of allergic rhinitis, as an example (you can find more details about this process in Chapter 2):
Ragweed pollen enters your body, usually as a result of inhaling it through your nose.
Your immune system detects the presence of these foreign substances in your body and stimulates the production of
IgE antibodies
, a special class of antibodies.
IgE antibodies attach themselves to the surfaces of mast cells that line tissues throughout your body, especially in your nose, eyes, lungs, and skin.
Your body designs IgE antibodies to counters specific substances.
Your immune system is a magnificent memory machine: Unlike you or me, it hardly ever forgets a face. After sensitization occurs, you’ll likely experience allergies to that substance for most of your life. With ragweed, for example, your immune system produces specific IgE antibodies with receptor sites that allow ragweed allergens to cross-link to the IgE ragweed-specific antibodies. The IgE antibodies work like a lock on the mast cell surface, and the allergen is the key. When the ragweed allergen connects with the two IgE antibodies on the mast cell surface, the bridging or docking mechanism unlocks the mast cell.
Unlocking the mast cell initiates the secretion of pro-inflammatory mediators such as histamines, leukotrienes, and other potent chemicals as a defensive response to the allergen.
In turn, the actions of these chemicals trigger the swelling and inflammation that result in familiar allergy symptoms.
Physicians frequently use antihistamines to relieve allergy symptoms because histamine plays such an important role in the inflammatory process. There are now more specialized drugs to counter and/or inhibit some of the more fundamental allergic processes. In particular, inhaled corticosteroids, mast cell stabilizers, leukotriene modifiers, and new biologic monoclonal antibodies provide new therapeutic approaches to preventing and controlling symptoms of allergic and asthmatic reactions.
Managing Allergic Disease Effectively
In most parts of the world, allergies cause a wide range of problems for millions of people. Allergy problems can involve occasional minor symptoms, serious episodes and attacks, and even potentially life-threatening reactions (in the most severe cases).
However, thanks to recent medical breakthroughs in our understanding of the underlying allergic and immunological factors involved in allergic reaction, it’s now possible in most cases to properly diagnose what’s ailing you and to develop an appropriate and effective treatment plan for controlling your symptoms and managing your condition.
Effectively managing allergic conditions — particularly asthma and allergic rhinitis — frequently requires dealing with an assortment of symptoms, treatments, and preventive measures, because allergies (as well as asthma) tend to be ailments with many faces. Think of a typical Chinese restaurant menu: You many need to order dishes from different columns in order to have a complete meal. See Chapter 6 for information on managing your condition.
Previewing Allergic Conditions
Consider this part of the chapter a preview of forthcoming reactions. In the following sections, we touch on the significant features of the most common allergic diseases and provide important details about distinguishing them from nonallergic conditions that are similar. We also include references to the chapters where we discuss these ailments in more extensive detail.
Allergic rhinitis: Running away with your nose
Frequently referred to as hay fever, allergic rhinitis is the most common allergic disease in the United States. As many as 45 million Americans or more suffer from some form of this allergy. Trademark symptoms of allergic rhinitis include runny nose with clear, watery discharge; stuffy nose, sneezing; postnasal drip; and scratchy nose, ears, palate, and throat. In addition, itchy and watery eyes, symptoms of allergic conjunctivitis (inflammation or swelling of the eye due to an allergic reaction) are often associated with allergic rhinitis. Infections of the middle ear (known as the otitis media) and of the sinuses (sinusitis) are frequent complications of allergic rhinitis.
In Part 2 we discuss the many forms of allergic and nonallergic rhinitis, and we also explain the ways physicians diagnose and treat these ailments (including allergic conjunctivitis). We also share important tips on avoiding triggers of various types of rhinitis, details on medications, and information on the complications of allergic rhinitis symptoms.
Asthma: Breathing and wheezing
The most fundamental definition of asthma is a chronic, inflammatory airway disease of the lungs that causes breathing problems. However, in practice, asthma has many faces and is often difficult to recognize and properly diagnose. As a result, even though currently available prescription medications offer effective ways of relieving, preventing, and controlling the symptoms and underlying inflammation (redness, swellings, congestion, and disruption of normal processes of the airways of your lungs) that characterize asthma, the disease continues to cause serious problems for many people worldwide.
Inflammation of the airways (bronchial tubes) is the most important underlying factor in asthma. In the vast majority of cases, if you have asthma, your symptoms may come and go, but the underlying inflammation usually persists.
Asthma’s characteristic symptoms are coughing, wheezing, shortness of breath, chest tightness, and productive coughs (coughs that produce mucus). Important symptoms of asthma in infancy and early childhood include wheezing, persistent coughing, and recurring or lingering chest colds. (Because of its symptoms, asthma in children is often misdiagnosed as recurring bronchitis, recurring chest colds, or lingering coughs.) Asthma — like most allergies — is a manifestation of atopy. In fact, many people with asthma also have allergic rhinitis.
The hyperreactive response of the sensitized immune system to asthmatic triggers (typically inhalant allergens, such as dander and dust mites, as well as other substances, including irritants, which also trigger allergic rhinitis symptoms) is usually the main factor in aggravating the underlying airway inflammation (see Chapter 8 for a detailed explanation of this process).
In Part 3 we examine asthma, including diagnosis, treatment, ways to avoid asthma triggers, asthma medications, long-term asthma management, and special considerations involving asthma during pregnancy and childhood.
Atopic dermatitis: Scratching your itch
Also describes as atopic eczema or allergic eczema, atopic dermatitis is an allergic condition that targets your body’s largest organ — your skin. The simplest way to define this noncontagious skin condition is the itch that scratches (or the “itch that rashes”).
“The itch that scratches” refers to the itch-scratch cycle, the hallmark of atopic dermatitis. Scratching your dry skin causes more irritation and inflammation, further damaging your skin and making it even itchier, resulting in more scratching and increasingly irritated skin. Eventually, fissures and cracks can develop on your skin, allowing irritants, bacteria, and viruses to enter, often leading to complicating infections.
Atopic dermatitis frequently occurs with allergic rhinitis and can also precede other allergic symptoms. As such, atopic dermatitis can provide an early clue that you’re at risk of developing other allergies and asthma.
This section just scratches the surface of information on atopic dermatitis. If you’re itching for more, see Chapter 11.
IT’S IN YOUR AIRWAYS, NOT IN YOUR HEAD
For centuries, many people believed that psychological factors such as anxiety, emotional disorders, or stress cause asthma. However, although these problems can aggravate asthma or allergies, they don’t by themselves cause asthma or allergies.
Unfortunately, we still hear about the friends and family of people with asthma who claim that asthma is all in the patient’s head. Some of these people insist that if the person would just calm down, their condition would go away. Instead of stress causing asthma, it can be the other way around: Breathing problems can cause stress. Stressing out because you can’t breathe is a perfectly normal and understandable response.
Therefore, a proper diagnosis of asthma and/or allergies, and early, aggressive treatment for these conditions are crucial. In most cases, you should be able to control your asthma and allergic condition so that it doesn’t control you, thus enabling you to lead a full and active life. Forget the negative stereotypes of people with asthma and people with allergies as nerdy, weak, anxious types, forever coughing and blowing their noses. Asthma and allergies can affect anyone: from the captain of the school chess team to the captain of the football team, as well as everybody in between.
Allergic contact dermatitis: Touching experiences
Although you may not know it, you’re probably already familiar with allergic contact dermatitis, because one of the most common triggers of this condition is poison ivy and other related plants of the Toxicodendron family. Other important triggers include latex, nickel, and formaldehyde.
The characteristic signs of allergic contact dermatitis include red rash, swollen pimples, blisters, and itchy skin. These symptoms may appear hours to days after your skin contacts an allergen, and they usually develop where the allergen touches the skin. As you may expect, the point of allergen entry is where the skin usually shows the most severe inflammation. Chapter 12 provides more detailed information on diagnosing and treating allergic contact dermatitis, avoiding triggers of this allergy, and preventing poison ivy from ruining your picnic or camping trip.
Urticaria and angioedema: Breaking out and swelling up
Urticaria and angioedema, better known as hives and deep swelling, can present perplexing problems. Figuring out why hives happen could give you hives — if that weren’t one of the most common misconceptions about these skin eruptions. In fact, contrary to popular belief, stress and other psychological factors aren’t the primary causes of hives but may possibly aggravate a pre-existing condition.
Another common myth is that hives and angioedema (deep swellings) always result from allergic reactions. In fact, although allergies can cause some cases of acute (rapid onset) hives and angioedema, more often these eruptions occur as a result of nonallergic mechanisms, especially in cases of chronic hives.
Angioedema usually coexists with hives. Deep swellings that develop without hives can indicate a serious underlying disorder or may signal a severe, adverse drug reaction.
The most common allergic triggers of hives and angioedema are
Food hypersensitivities, especially peanuts, tree nuts, milk, eggs, fish, shellfish, soybean, sesame, and fruits such as melons and berries. (See
Chapter 14
for more information on food allergies.)
Insect stings from insects of the
Hymenoptera
order (honeybees, yellow jackets, wasps, hornets, and fire ants) can often cause small, localized hives that develop into blisters if you’re sensitized to the venom of these insects. In rare cases,
anaphylaxis
, a life-threatening reaction that affects many organs simultaneously (see the section “
Anaphylaxis: Severe systemic symptoms
” later in this chapter), can follow an insect sting. Refer to
Chapter 17
for more information on insect stings.
Medications, including penicillin, sulfa drugs, and other antibiotics; aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs); insulin; narcotic pain relievers; muscle relaxants; and tranquilizers can trigger systemic hives if you have sensitivities to allergens in these products. See
Chapter 16
for more information on drug reactions.
Chapter 13
goes into much deeper detail about hives and angioedema.
Food hypersensitivities: Serving up allergens
Most adverse food reactions aren’t the result of true food hypersensitivities (the more precise terms for food allergies). In fact, various forms of food intolerance, food poisoning, and other nonallergic mechanisms cause the majority of reactions that most people blame on food allergies.
The most frequent triggers of actual food hypersensitivities are proteins in the following foods:
Peanuts and other legumes, including soybeans, peas, lentils, beans, and foods containing these ingredients
Shellfish, including crustaceans and mollusks such as shrimp, lobster, crab, clams, mussels, and oysters
Fish, both freshwater and saltwater
Tree nuts, including almonds, Brazil nuts, cashews, hazelnuts, pistachios, pecans, and walnuts
Eggs, especially egg whites
Cow’s milk, including products that contain casein and whey
Soy, including soy products like soy milk, tofu, tempeh, and miso.
Wheat and other grains and cereals, such as corn, rice, barley, and oats
Sesame from foods that contain sesame seeds, such as hummus
In cases in which mouth and lip swelling, wheezing, or hives occur immediately after consuming a particular food (peanuts, for example), you many easily deduce that an allergic response caused your reaction. However, in many other instances, distinguishing between food intolerance and true food hypersensitivity can require more extensive diagnostic procedures. If you’re hungry for more information on adverse food reactions, see Chapter 15.
Drug hypersensitivities: Taking the wrong medicine
Certain drugs are prone to produce allergic reactions in susceptible individuals. The most frequent type of adverse allergic reactions to medications occurs with penicillin and its related compounds. Aspirin and related NSAIDs — including newer prescription NSAIDs, known as COX-2 inhibitors, such as celecoxib (Celebrex) — and other drugs can also trigger adverse reactions. However, most adverse drug reactions result from nonallergic mechanisms, as we discuss in Chapter 16.
Although drug hypersensitivity reactions most frequently target the skin, adverse allergic reactions to drugs can affect any organ system in your body, including mucous membranes, lymph nodes, kidneys, liver, lungs, and joints. These reactions can trigger skin rashes, hives, angioedema, respiratory symptoms such as coughing or wheezing, fever (sometimes resulting in drug fever, occasionally with shaking chills and a skin rash), and low blood pressure and /or anemia, resulting from an adverse reaction that destroys your red blood cells.
In less frequent but more serious cases, an adverse drug reaction can result in anaphylaxis, a severe, potentially life-threatening response that affects many organs simultaneously (see the section “Anaphylaxis: Severe systemic symptoms” later in this chapter). In fact, penicillin injections cause the most drug-related anaphylactic deaths in the United States. (Fortunately, the use of penicillin shots has significantly decreased in recent years.) For more information on drug hypersensitivities, see Chapter 16.
Stinging insects: The wrong kind of buzz
The venom of stinging insects from the Hymenoptera order (honeybees, yellow jackets, wasps, hornets, and fire ants) can trigger allergic reactions in people who are sensitized to those allergens. Reactions range from discomfort, swelling, itching, and hives to — in rare cases — potentially life-threatening anaphylaxis.
Like allergic contact dermatitis, insect-sting hypersensitivities are equal-opportunity allergies. Having other allergic conditions, such as allergic rhinitis, asthma, atopic dermatitis, or food allergies, or a family history of atopy puts you at no greater risk than anyone else for experiencing an allergic reaction to stings from these insects.
In Chapter 17, we provide extensive details on these insects and how you can avoid venomous encounters with them.
Anaphylaxis: Severe systemic symptoms
Anaphylaxis, an ultimate but thankfully rare form of allergic reaction, involves a severe, potentially life-threatening response that affects many organs simultaneously. The characteristic signs of anaphylaxis include
Flushing (sudden reddening of the skin)
Dramatic itching over the entire body
Itchy rash or hives
Nausea, vomiting, abdominal pain, and/or diarrhea
Swelling of the throat and/or tongue (limbs may also swell)
Difficulty breathing
Dizziness or fainting
Severe drop in blood pressure
The most frequent causes of anaphylaxis in the United States are extreme allergic reactions to the following allergens:
Venom from stinging insects of the
Hymenoptera
order
Drugs such as penicillin and related compounds
Foods — particularly peanuts and shellfish
In addition, pseudoallergic or idiosyncratic reactions (see Chapter 16) caused by drugs such as aspirin or related OTC NSAIDs like ibuprofen (Advil, Motrin), ketoprofen (Actron, Orudis), naproxen (Aleve), and newer prescription NSAIDs, known as COX-2 inhibitors, including celecoxib (Celebrex), can (in some cases) lead to severe, potentially life-threatening reactions referred to as a non IgE-mediated immune response or as an anaphylactoid reaction, involving direct activation of certain immune cells such as mast cells and basophils (see Chapter 2).
If you’re at risk of anaphylaxis, you should be prepared to take emergency measures to prevent this type of extremely serious reaction. Consult with your physician about prescribing an emergency kit (such as EpiPen or Auvi-Q) that contains an injectable dose of epinephrine, or the single dose epinephrine nasal spray called “neffy,” which was recently approved by the U.S. Food and Drug Administration (FDA).
Make sure that your physician shows you how to use the injectable device. Learning the proper technique for administering epinephrine in your physician’s office is much more effective than trying it out for the first time while you’re having a reaction.
Because anaphylaxis is such a serious issue and can result from various types of exposures, we address it throughout the book, wherever applicable.
DYEING YOUR ALLERGIES
Inhaled topical corticosteroids, which are often used as asthma and allergy treatments — including budesonide (Pulmicort, Rhinocort), mometasone (Asmanex, Nasonex), and other inhaled topical corticosteroid products that we list in Chapter 6 — are extremely effective in suppressing the inflammatory process. Keep in mind, however, that most asthma and allergy drugs treat the end result of a long, complex chain of immune system reactions but don’t fundamentally prevent the underlying process causing your ailment. Therefore, if you stop taking your prescribed medications, the underlying disease process most likely restarts, and your clinical symptoms reappear.
We compare this process to dyeing your hair. You can change your hair color, but if you don’t continue coloring it (like treating your asthma and allergies with your prescribed medicine), your new hair growth comes in with its original color, because you haven’t really altered its underlying, genetically determined characteristics.
Diagnosing and Treating Allergic Disorders: Just the Basics
The basic components of effectively managing allergies include the following steps.
Getting a proper diagnosis of your condition
. Identifying the specific allergens, irritants, and/or precipitating factors that may trigger your ailment is a critical component of your diagnosis. Cough medicine isn’t the treatment for your cough if you have asthma. First finding out why you're coughing (cough may be the only obvious symptom of underlying asthma in certain patients) is vital so you can then take appropriate steps to effectively control and manage your condition.
Avoiding or reducing exposures to allergens, irritants, and precipitating factors that may trigger your asthma and/or allergies.
Effective avoidance and allergy-proofing measures (see
Chapters 5
and
9
) can significantly improve your quality of life and often reduce, or in certain cases eliminate, your need for medication.
Taking long-term preventive medications to control your underlying condition while appropriately using short-term medications when you experience flare-ups, episodes, or attacks.
We provide extensive information on prescription and over-the-counter allergy and asthma products in
Chapters 6
and
10
.
Evaluating and monitoring your condition.
Consider having a comprehensive evaluation by a board-certified allergist to confirm your diagnosis and to follow your clinical course.
Adhering to your treatment plan and keeping yourself informed about all aspects of your condition.
Follow the recommendation of your physician, take your medicines as prescribed, and come prepared with any questions you might have at the time of your office appointments.
Keeping yourself in good general health (by eating healthy and exercising) to avoid developing more severe symptoms or potential complications of your ailment and to help you enjoy the highest quality of life possible.
Good health and an active lifestyle will certainly help you maintain an excellent quality of life and allow you to participate in the activities that bring you enjoyment.
CLIMATE CHANGE AND THE INCREASING INCIDENCE OF ALLERGIC CONDITIONS
A significant factor contributing to the increase in allergic disorders in recent years, is climate change. Warmer temperatures coupled with increased carbon dioxide levels in the atmosphere, create ideal conditions for plants to produce more pollen, lengthening seasonal allergies and intensifying pollen concentrations.
This prolonged exposure to allergens exacerbates existing allergies and may even trigger new allergies in sensitive individuals. The extreme weather events, caused by climate change, such as intense heatwaves and flooding, worsen air quality by increasing environmental pollutants and mold spores, which further aggravates respiratory allergies such as asthma and allergic rhinitis.
Chapter 2
Understanding Your Immune System
IN THIS CHAPTER
Differentiating immunity from allergy
Understanding how your immune system works
Examining immune system disorders
In terms of germs, the world can still be a rough place. Despite major advances during the last 100 years in fighting infectious diseases and providing effective medical care for increasing numbers of people, viruses, bacteria, fungi, and other potentially harmful agents remain constant threats to your health. That’s why your body’s defense network is so important to your well-being.
Your front-line defense against potentially infections intruders is the physical barrier formed by your body’s largest organ — your skin. (Your mucus membranes, as well as the highly acidic digestive juices of your stomach, the beneficial bacteria in your gut, and certain nonspecific cells, also act as immediate defenders against uninvited guests.) The second far more complex and fundamental defense apparatus in your body — and one of the most important keys to the survival of the human species — is your immune system.
Because numerous immune system processes can play important roles as underlying factors in allergy and asthma (as well as in many other diseases), doctors frequently need to apply their understanding of immunology (the science of immunity) when evaluating and treating allergic conditions.
We devote this chapter to explaining the immunologic basis of allergic reactions so that you can have a better understanding of what may be at the root of your ailment and to review with you what your physician considers when diagnosing and treating your condition.
Protecting Your Health: How Your Immune System Works
The most basic function of your immune system is to distinguish between your body (self) and potentially harmful (non-self) agents. Your immune system performs the following functions to protect you:
Recognizes foreign (therefore, potentially harmful) microorganisms, their products, and toxins, all known generally as
antigens
. These substances can stimulate a response from your immune system and react with an antibody or a sensitized
T-cell
(a specialized immune system cell involved in cell-mediated immunity, as we explain in “
Reacting to allergen exposures
,” later in this chapter). Allergens, which usually consist of proteins, are particular types of antigens, which initiate an allergic response.
Identifies self-antigens. These antigens are usually damaged and/or improperly functioning cells in your body. Malignant cells that can develop into tumor-causing cancerous cells are an example of self-antigens.
Assists in removing antigens from your body.
The immune system defense is vital to the survival of all animals. If your immune system functions properly, its protective function is an underlying, ongoing, and generally imperceptible aspect of your everyday existence.
Your immune system can work as a double-edged sword, however. In some cases, it deploys its defensive functions too zealously while trying to protect your body against any type of perceived threat. In such cases, rather than preventing infections, your immune system can actually instigate certain types of health problems, including
Autoimmune disorders: These disorders include serious diseases such as rheumatic fever, a rare complication of an inadequately treated strep infection of the upper respiratory tract (strep throat), in which the immune system can attack heart tissue cells that cross-react with Streptococcus bacterial antigens. This kind of complication is why it’s so important that you take the full course of antibiotic therapy your physician prescribes for strep throat and that you return to your doctor’s office of a repeat throat culture to make sure that your infection has completely resolved. (For more information on cross-reactivity, see Chapter 5.)
In other cases, the immune system (for reason researchers are still trying to discover) loses its ability to distinguish between certain self and non-self substances. This inability to make that distinction can cause diseases such as systemic lupus erythematous, psoriasis, rheumatoid arthritis, and some forms of diabetes, when your immune system perceives otherwise functional and vital cells in your body as antigens and turns its firepower on them.
Rejection of organ transplants:
Doctors usually try to find a close genetic match between patient and organ donors to reduce the risk of the patient’s immune system rejecting the donated organ. In many cases, however, physicians still need to administer drugs to suppress the patient’s immune system and prevent organ rejection. This suppression of the immune system can then increase the risk of opportunistic infections potentially harming the patient.
Allergic conditions:
If you have allergies or asthma, you almost certainly have an immune system that works too well or overreacts. As we explain in
Chapter 1
, doctors use the term
hypersensitivity
to refer to allergies because your immune system is overly sensitive to substances such as certain food proteins, carbohydrates, pollens, animal dander, and other types of allergens that offer no real threat to your health. With hypersensitivity, your immune system acts like an alarm system that summons a SWAT team regardless of whether a cat burglar or just a cat is intruding on your property.
Classifying Immune System Components and Disorders
Your immune system consists of several related processes. Think of these processes as a civil defense network of arsenals, supply lines, logistical support, and command and control centers for the cells that actually defend your body. The most important organ and tissue components of your immune system include the following:
Bone marrow:
This is where stem cells (early, non-specific types of cells) originate, developing into
B-cells
(specialized types of plasma cells) that subsequently secrete distinct forms of plasma proteins, known as
antibodies
. These antibodies are divided into the following five classes of
immunoglobulins
(identified by the prefix Ig):
IgG:
The major component of gammaglobulin used for treating certain types of immune deficiencies, IgG antibodies account for at least three-quarters of the antibodies in your body. This class of antibodies, together with IgM antibodies, in cooperation with your white blood cells, is vital in defending you against bacterial infections. IgG antibodies also play an important role in preventing allergens from initiating an allergic reaction. As a response to
immunotherapy
(allergy shots), the production of IgG antibodies is believed to work by blocking IgE antibodies from binding to mast cells, thus preventing the subsequent release of chemical mediators of inflammation that produce allergy and asthma symptoms. (See “
Reacting to allergen exposures
,” later in this chapter for more information.)
IgM:
About 5 percent of your antibodies belong to this class, which plays a role in the primary immune response and also enhances the role of IgG antibodies.
IgA:
The primary antibody in your mucus membrane surfaces, IgA antibodies reside in your saliva, tears, and in the secretions of the mucosal surfaces of your respiratory bronchi, gastrointestinal, and genital tracts, where these antibodies protect against infection. They’re also present in mother’s milk for the first few days after giving birth, thus providing antibody protection (referred to as
passive immunity
) for breast-fed newborns.
IgD:
This antibody class, which works with the antigen at cell surface contact, seems to exist in very small quantities and plays a nonspecific role in the immune process.
IgE: Although present in only minute quantities in your body, IgE antibodies (also known as reaginic antibodies) are key players in allergic reactions (hence the longer paragraphs; these antibodies are probably the reason you’re reading this book). Although everyone produces IgE antibodies, allergy sufferers have an inherited tendency to overproduce these agents. IgE antibodies can induce other cells, particularly mast cells and basophils (special sentinel cells, as we explain in “Reacting to allergen exposures,” later in this chapter), to set in motion a complex chain reaction that culminates in your allergy and asthma symptoms.
Mast cell surfaces have special IgE receptor sites. Two allergen-specific IGE antibodies linking to an allergen (such as pollen, animal dander, molds, dust mite allergens, insect sting venom, and certain foods and drugs) on the surface of the mast cell can trigger a Type 1 allergic reaction, also known as an IgE mediated allergic reaction (see “Classifying Abnormal Immune Responses,” later in this chapter).
Cytokines:
These signaling proteins play an important role in nearly all aspects of inflammation and immunity. They’re chemical messengers that tell your cells how to behave. Some cytokines make disease worse (proinflammatory), while others act to reduce inflammation and have a healing effect (anti-inflammatory).
Interleukins
are a group of cytokines that act as chemical signals between white blood cells. The major anti-inflammatory cytokines include interleukin-4 (IL-4), IL-6, IL-10, IL-11, and IL-13. Inflammatory cytokines include interleukin-1 (IL-1), IL-12, and IL-18. Interleukin-5 (IL-5) is known to be a pro-inflammatory cytokine that controls the production, activation, and localization of eosinophils that mediate allergy and asthma symptoms.
TSLP:
Thymic stromal lymphopoietin is an epithelial cell-derived cytokine expressed in the skin, gut, lungs, and thymus. It activates dendritic cells to promote T helper (Th) 2 immune reactions. It’s a key mediator of asthma and can cause severe allergic airway inflammatory responses by its action on adaptive and innate immune cells and structural cells.
Thymus:
Secretions of special hormones (such as thymosin) from this gland are vital for regulating your immune system’s functions. The thymus also helps encode certain T-cells, which then play key role in developing antibodies against antigens.
Lymph nodes:
The lymphatic system provides drainage for your immune system. Your lymph nodes filter out material resulting from a local inflammatory reaction. If you seem to have, for example, strep throat, your doctor checks for swollen lymph nodes downstream from the infected area (under your throat) as an indication of infection.
Spleen:
This organ filters and processes antigens in your blood.
Lymphoid tissues:
These important immune system participants, which include your tonsils, adenoids, appendix and parts of your intestines, help process antigens.
INFLAMING YOU FOR A GOOD REASON
You may wonder why you’re equipped with IgE antibodies if they’re so problematic. This seemingly bothersome immunoglobulin is a significant part of the reason the human species made it to another millennium. During prehistoric times, in addition to the challenges of hunting and gathering our daily meal (and trying not to become another animal’s chow in the process), humans also had to contend with all sorts of infectious agents, especially parasites.
The potent inflammatory action triggered when a parasite-specific antigen would bind with cell-bound IgE antibodies probably insured that parasitic infections couldn’t affect enough humans to endanger our species. In fact, IgE antibodies remain important players in the immune responses of some people in less-developed regions of the world, where parasites continue to pose threats to human health. I have seen patients who have recently arrived from less-developed countries and who have highly elevated IgE and eosinophil levels in their blood tests. In those cases, I rule out parasitic infections before moving to a more likely diagnosis of an allergic condition. However, because parasites are such an extremely rare problem in the U.S. population, elevated IgE and eosinophil levels are almost always a sign that I’m dealing with an allergic patient.
In most modern-day humans, IgE antibodies play a role similar to that of fat cells. In prehistoric times, humans needed fat cells to store food and stave off hunger when their hunting and gathering was less than productive. Now, human fat cells turn into love handles, and IgE antibodies trigger allergies.
