part 2:what are allergies? - science...

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Healthy immune systemThe immune system is so complexthat some of the way it works isnot yet understood. What scien-tists do know is that a healthyimmune system battles infectiousagents in an effort to keep thebody free of disease. When a disease-producing organisminvades the body, the white bloodcells (called leukocytes) form akind of army that gathers togeth-er to prevent infection. Leuko-cytes also work to repair anydamage done by an invader.

Just as there are a variety of foreign materials that act asinvaders (viruses, bacteria, para-sites, and fungi), there are manytypes of white blood cells.Different ones have differentfunctions. One type, called neutrophils, ingests bacterialinvaders and produces the chemi-cals that destroy them. Whateverthe type, white blood cells worktogether to help produce thebody’s immune response.

White blood cells are assisted bylymphocytes—cells that play the

most prominent role in helpingthe body create a natural resist-ance to disease. There are twotypes of lymphocytes: B cells andT cells. B lymphocytes produceantibodies that do battle withantigens, the foreign substancesthat are created by an invader.When an invader enters the body,its antigens alert the immunesystem to the invader’s presence.

Part 2: What Are Allergies?

The immune system protectsthe body from harmful substances. The immunityresponse (inflammation) ispart of innate immunity. It occurs when tissues areinjured by bacteria, trauma,toxins, heat, or any othercause.

A s t h m a a n d A l l e r g i e s : T h e S c i e n c e I n s i d e

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When antibodies target the invad-er, they also send messages towhite blood cells to join the bat-tle. T lymphocytes attack cellsthat are foreign or that are infect-ed by a virus. They do this bygenerating antibodies that fightoff the foreign particles found ininvading cells. Their attack alsoincludes digesting the invaders orreleasing chemicals that candestroy them. Another job of the T cells is to help the bodyaccept—without overreacting to—the chemicals that are found inallergy shots.

Among the substances that theimmune system encounters areallergens, which can trigger aller-gic reactions in many people.Some of the most common aller-gens are pollen, mold, and animaldander, as well as cockroach and

house dust mite droppings.Scientists do not know why somesubstances are allergens for somepeople and harmless for others.

The body has two main ways ofprotecting itself. Innate immu-nity is the body’s first line ofdefense. It includes the barriersthat keep antigens from enteringyour body, such as the skin,mucus, stomach acid, the coughreflex, and enzymes in tears andskin oils. An antigen that getspast these barriers then has toface other parts of the immunesystem, such as certain whiteblood cells that “eat” microorgan-isms and dead or damaged cells.Inflammation, or swelling, is alsopart of innate immunity. Bloodvessels leak fluid into damagedtissues. This swelling keeps for-eign substances away from otherbody tissues.

Active (acquired) immunityis slightly different, occurringwhen the body responds to a foreign invader such as a virus. In active immunity, the bodyresponds to an antigen and buildsa defense that is specific to thatantigen. In other words, the firsttime the body comes in contactwith a foreign invader, it createsantibodies that attack only thatinvader. The next time the sameantigen enters the body, the


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immune system is already pre-pared to fight it. In a sense, theimmune system “remembers” theantigen.

When a body has a healthyimmune system, some invaderscan be conquered before they cre-ate the condition that leads todisease. The damage from otherinvaders that succeed at first canbe minimized and repaired. Whenan immune system is not healthy,it is not able to work as well infighting off these invaders. Insome cases, an immune systembecomes so compromised that itshuts down and is unable to fightoff or contain any disease-produc-ing organisms.

Problems associated with allergiesA person with allergies has animmune system that overreacts tosubstances that do not producesymptoms in most people.Substances that are otherwiseharmless, such as animal danderor dust, can trigger a severe aller-gic reaction in a person who issensitive to them. For these peo-ple, animal dander and dustbecome allergens. A person withallergies might experience sneez-ing, wheezing, coughing, or anitchy feeling in the throat.

Allergic rhinitis (hay fever) is an inflammation of the mucousmembranes of the nose. It iscaused by the same types of sub-stances that trigger allergies.Outdoor triggers include grasses,trees, and weeds. Indoor triggersinclude mold, animal dander, andcockroach droppings. Treatmentssuch as allergen immunotherapy,medications, and, of course,avoiding the triggers can providesome relief. If not properly treat-ed, a person with rhinitis candevelop sinusitis.

There are two forms of sinusitis,a condition characterized by aninflammation of the sinuses, aplugged-up nose, a feeling thatthe face is swollen, toothache,tiredness, and fever. One type iscalled chronic sinusitis. Thiscondition is often caused by bac-terial infections and can be acause of chronic cough. Another

The animaldander frompets can trig-ger an allergicreaction in aperson who issensitive to it.


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type is called acute sinusitis.Also caused by bacterial infections,acute sinusitis can appear severaldays after the first sign of a cold.Exposure to tobacco smoke andchemical odors can make symp-toms worse. People with allergiesseem to be predisposed to develop-ing acute sinusitis, perhapsbecause allergies tend to lead toinflammation of the sinuses andnasal linings. The inflammationcan prevent bacteria from getting

cleared from nasal cavities. Long-term treatment for allergies cansometimes help prevent acutesinusitis from developing.

The symptoms of allergiesThe symptoms that an allergicperson experiences are determinedby the type of allergen that trig-gers the reaction, the site wherethe reaction occurs, and theimmune system’s response. Some

people suffer from symptoms thatare mainly consistent with hayfever: runny nose, congestion, and sneezing. Others experiencea reaction that is more typical of a response to a food allergy:swelling of the throat, difficultybreathing, and dizziness. Stillothers break out in hives, anitchy skin rash that forms in clusters, when exposed to a medication such as penicillin.

Allergic reactions can be quitedifferent and can range frommerely annoying to fatal. Themilder, more annoying symptomscan begin with watery, swolleneyes; an itchy, irritated nose andthroat; and hoarseness in thevoice. The nasal passages candrain profusely, through the frontof the nose or down the back ofthe throat. The symptoms cangrow more irritating as they startto reduce the person’s ability tobe active. Thick phlegm (mucoussecretions in the respiratory passages) can occur as the chestbecomes more congested. Cough-ing and sneezing can be so severethat the person becomes exhaust-ed from the effort both require.The skin can become one red,itchy, swollen rash. Abdominalcramps, vomiting, and diarrheacan make it impossible for a per-son to leave home. Still, howeverawful these symptoms sound,none is as bad as those sufferedduring anaphylaxis.

Anaphylaxis is a sudden, severeallergic reaction that can have avariety of symptoms. It is impor-tant to learn about these symp-toms, because anaphylaxis can befatal if it is not properly treated.This allergic reaction can involvemajor areas of the body at thesame time, such as the skin, therespiratory system, the gastroin-testinal tract, and the cardiovas-cular system. Symptoms canoccur within minutes of an expo-sure to a trigger (for example,after receiving an insect sting). It is important to remember,though, that sometimes symp-toms do not appear for severalhours (for example, after taking a medication).

Symptoms associated with vari-ous forms of anaphylaxis includefever, swelling throughout thebody or in one area, difficultyswallowing or breathing, nausea,


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Anaphylaxis

vomiting, diarrhea, abdominal oruterine cramping, congestion, afeeling of having to urinate, hives,swelling of the lips and joints,severe anxiety, headache, itching,sneezing, coughing, and wheezing.The most dangerous symptoms ofanaphylaxis are low blood pres-sure, breathing difficulties, shock,and loss of consciousness.Sometimes anaphylactic symptomsare misdiagnosed as hyperventila-tion, anxiety attacks, low bloodsugar, or drug and alcohol intoxi-cation. A misdiagnosis can bedeadly.

There are no cures for this varietyof allergic reaction, but many

promising treatments can preventor control the symptoms. (Seepages 56–57 for information abouttreatments.)

The causes of allergiesThe exact cause of allergic reac-tions is not known. However, thereappears to be a hereditary compo-nent to the more common forms ofthe condition. If one parent hasallergies, a child’s risk of develop-ing the condition is 48%. If bothparents suffer from allergic reac-tions, the child is 70% likely todevelop allergies. When it comes to allergies, the important ques-tion to ask is not why, but what. If a person can determine—


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through experience that is con-firmed by testing—what it is thattriggers symptoms, treatment can begin.

There is an extensive list ofknown or suspected allergens.Each person with allergies reactsto specific substances. Someonefor whom pollen is a problemmight have no allergic reaction tomold. People who are allergic tocats are not necessarily sensitiveto dogs. Some foods and medica-tions trigger reactions in people;others do not. Some people canwork in an environment in whichthey are exposed to a chemicalthat triggers an allergic reactionwithin days of their first expo-sure. For other people, this reac-tion might take years to appear.

Anaphylaxis can be caused byexposure to some common sub-stances, such as foods, medica-tions, insect bites, and certainmaterial, such as latex. Exercisecan also produce anaphylacticsymptoms, but not consistently.Allergens that induce anaphylax-is include the following:

• Foods and additives: A traceamount of peanuts, tree nuts(for example, walnuts oralmonds), shellfish, fish, milk,or eggs can trigger an allergicreaction in some people. This

reaction can occur quickly.Additives such as sulfides—found in beer, dried fruit, pick-les, and potato products—canalso cause anaphylaxis, espe-cially in asthmatics.

• Medication: There is anincreased chance of developingan allergy to medication if themedicine is given frequently, in large doses, or by injection.This reaction usually occurswithin hours of exposure.

• Insect stings: Honeybees,bumblebees, yellow jackets,hornets, wasps, fire ants, andharvester ants are the insectsthat cause most anaphylacticsymptoms, which occur withinminutes of the sting or bite.

• Latex: Those who work in thehealth care or rubber industriesare exposed to latex so oftenthat some develop allergic reac-tions to the material. Childrenwho have congenital diseaseslike spina bifida often havemany early exposures duringtheir numerous surgeries. They, too, can develop an aller-gy to latex. Certain foods thatcross-react with latex can trig-ger allergic reactions in thesesame people. These foodsinclude bananas, kiwi, avoca-dos, European chestnuts, pota-toes, tomatoes, peaches, plums,

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cherries, and other fruits withpits.

A less common type of allergicreaction is called food-dependentexercise-induced anaphylaxis.Symptoms occur after a personexercises within 3 or 4 hours ofeating a certain food. The foodsthat have been known to causethis reaction are wheat, shellfish,fruit, milk, cereal, and fish.Usually, those who experience thereaction already have asthma aswell

as other allergies.

In some cases, a person can experi-ence what is called a biphasicreaction. This happens when ananaphylactic reaction occurs. Afterthe reaction, the symptoms goaway, only to return hours later.For this and other reasons, it isimportant for a person havingthese symptoms to stay at a hospi-tal for several hours following thefirst signs of trouble. Even if med-ical staff indicate that a person is


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free to go home, it is best to sit inthe hospital lobby for a few hoursjust to make sure that the symp-toms do not return. Doing socould save the person’s life.

How allergies affect the bodyA person can be allergic only tosomething to which he or she hasalready been exposed. In otherwords, an allergic response occursafter an initial exposure to a sub-stance to which the person’simmune system is sensitive. It isreexposure to the substance thatproduces the allergic reaction.

The first time an allergen entersthe body of a person who is likelyto develop allergies, a certaintype of allergen-specific antibodyis produced. This antibody, calledimmunoglobulin E (IgE), trav-els to mast cells in many areas ofthe body. Mast cells are com-monly found in the nose, eyes,lungs, and gastrointestinal tract.IgE antibodies attach themselvesto the surfaces of these mastcells. Each IgE antibody is wait-ing for an invasion by a particular allergen.

Let’s say that a person is predis-posed to developing an allergy tocat dander. The IgE antibody forthat allergen can be found on thesurface of that person’s mast

cells. He or she might develop anallergy to cat dander only. Thismeans that the person’s allergieswill not be triggered by dog orhorse allergens, unless, of course,those allergen-specific IgE anti-bodies are present as well.

Therefore, the IgE antibodies tocat dander have “set up camp” on the mast cells. The very nexttime that the person comes intocontact with cat dander, thisallergen will enter the body. Thewaiting IgE antibodies will cap-ture these cat dander allergens.Once this happens, chemicalssuch as histamine are releasedfrom the mast cells. These chemi-cals, often called mediators, areresponsible for producing thesymptoms of an allergic reaction,such as sneezing and coughing.As the person continues to beexposed to the cat dander aller-gen, the reaction continues.Already inflamed tissues mightgrow more inflamed as thesechemicals draw other swollencells to the area.

The reaction that the person hasdepends upon the location of themast cells to which the IgE anti-bodies have attached. For exam-ple, if an allergen such as pollentouches the lining of the nose, asis common in allergic rhinitis (hay fever), the mucous mem-branes that line the nose will

become inflamed and congested.The person will experience a drip-ping nose and watery, itchy eyes. If the person continues to beexposed to the allergen that trig-gered the reaction, the symptomswill continue the same way.

A person with a very different trigger—for example, a food thatproduces eczema—will experiencesymptoms that affect the skin. For 80% of those with eczema, thiscondition—itchy, reddening, flak-ing, and peeling skin—begins inchildhood. Another skin-specificallergic reaction can occur from an infection, eating a certain food,or taking a certain medication.

Hives can cover the skinwith small or large clus-ters of itchy, red bumps.Children experience aller-gic reactions to food morefrequently than adults do.Over time, a child canbecome less sensitive tofoods that were once aller-gy triggers.

Food can also be a triggerfor anaphylaxis. A personwho is in immediate dan-ger from this severe aller-gic reaction should begiven an injection of epinephrine (adrenaline)as soon as possible.Otherwise, the episodecould be fatal. Epine-

phrine is a body chemical that isproduced naturally by the adrenalglands. Used in injections, a syn-thetic form of the chemical fightsallergic reactions in several ways.Epinephrine opens constricted airpassages, constricts dilated bloodvessels, elevates low blood pres-sure, and halts the swelling that iscommon with hives.

How allergies affect lifestylePeople with allergies suffer fromsymptoms whenever they areexposed to the provoking allergens.In some cases, a person can avoidthe trigger. If shellfish provokes an


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Children haveallergic reac-tions to foodmore oftenthan adultshave. As theygrow older,they may outgrow some of these allergies.

allergic reaction, a person couldsimply avoid exposure to anyform of this food.

With other allergy sufferers,avoiding the allergen is not aseasy. If the trigger is airborne,how can a person avoid exposureif the trees, grasses, weeds, andmolds that thrive from Januaryto December each year are theculprits? Even if allergies are sea-sonal, this still means that formonths each year, the personmust avoid the outdoors. If a per-son working as a nurse developsan allergic reaction to latex, whatcan be done? There are latex-freegloves available, but latex in vari-ous forms can be found every-where within the environment inwhich the person must work. A food allergy can be so severethat simply avoiding direct contact with the food is not sufficient.

Peanut allergies are among themost common allergies in theUnited States. Children rarelyoutgrow peanut allergies. Peoplewho are allergic to peanuts find itdifficult to avoid the many formsof the nut that are triggers. A child with a peanut allergymust avoid exposure to groundnuts, mixed nuts, peanut butter,peanut oil, and peanut flour. All utensils and surfaces that are

used to prepare foods containingnuts must be avoided as well. Theprotein that causes an allergicreaction to peanuts can becomeairborne. Therefore, a child witha peanut allergy can have a reac-tion from sitting in an environ-ment in which peanuts or peanutproducts are cooked or con-sumed—for example, in a cafete-ria in which other children areeating peanut butter or in aChinese restaurant where eggrolls are being prepared.

Allergies of all types have drivenpeople to significantly restricttheir activities. Many people withsevere allergies feel as if everyenvironment holds potential dan-gers. Especially if a child is suf-fering from allergies, it is impor-tant to create an environment inwhich there is little fear of symp-toms and an expectation existsthat the child can meet the chal-lenges of daily living. Usually, a


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Peanut allergiesare among themost commonallergies in theU.S.

combination of avoidance, allergenimmunotherapy, and medication isneeded to give an allergy sufferermore freedom to live a normal life.Many with allergies have had toendure the difficult side effects ofmedications that were used totreat their symptoms. At one time,antihistamines caused so muchdrowsiness that an allergy patienthad to decide whether to suffer theeffects of the allergy and remainalert or suffer the drowsinessbrought on by the medication.Today, many formulas that do not produce drowsiness areavailable.

Newer medications allow peoplewho have suffered life-threatening

allergic reactions to live more normal lives. There was a timewhen a person who had sufferedfrom anaphylaxis could not travelto any area of the world where acertain level of medical care mightnot be available. Some people wereso concerned about the availabilityof treatment that they lived closerto hospitals and ate dinner atrestaurants that were minutesaway from an emergency room.Now that epinephrine injectionsare portable and easy to adminis-ter, a dangerous insect sting orfood allergy can be treated imme-diately. Still, medical help shouldbe sought immediately after epinephrine is used.


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Epinephrineinjections aremore portablenow. This makesit easier for people with life-threateningallergies to leadnormal lives.


29Huntley-Fenner, continued on next page

Out from theShadow of AsthmaAt first, Gavin Huntley-Fenner’s asthmacame on slowly. While training with hishigh school wrestling team, he grewshort of breath whenever he ran lapsoutside in the cold. Huntley-Fennerdidn’t worry too much, though,because his symptoms were neversevere, and they disappeared in warmweather. A few years later, things grewmuch worse.

By then, his asthma attacks were so severe and frequent that he endedup in a hospital emergency room twice in one month. When he wasnear cats, his symptoms worsened. At times, it was impossible for himto climb a short flight of steps without stopping to rest. Huntley-Fennerdecided he needed to find a way to manage his disease for a lifetime.

When Huntley-Fenner puts his mind to something, the results are oftenimpressive. He earned his doctoral degree from the prestigiousMassachusetts Institute of Technology and began a research careerstudying how children learn to speak and to grasp the concepts ofnumbers and counting. His broad range of skills has made him asought-after business consultant in Southern California, where he nowlives with his wife and two children.

He approached his struggle with asthma with the same deliberate andcareful study.

“My key challenge right now as an asthmatic is that I’m on a lot ofmedication at high doses,” he says. “As I grow older and my diseaseworsens, I’m concerned that there will be less and less flexibility totreat flare-ups.”

So, with his doctor’s blessing, Huntley-Fenner tries to cut down on med-ications whenever possible, all the while being careful not to jeopard-ize his health. “Finding a doctor open to thinking through the problemwith you is important,” he recommends.


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His approach seems to be working. For now, Huntley-Fenner’s asthma doesn’t seem to be worsening. To keep his body strong, he seeks out waysto exercise that won’t cause an attack. “I have to be more creative in find-ing ways to keep fit,” he says matter-of-factly. “I can’t run around as muchas I would like with my kids, but we ride bikes. There are neighborhoodsoccer games that would be fun for me to join in, but I can’t. We’re manag-ing well, though. I can run on a treadmill. I can cycle. I can swim.”

For Huntley-Fenner, trying to minimize the impact his asthma has on his family is a main concern. He has worked to reduce the amount of dust and allergens in his home, which can aggravate his asthma. “We no longerhave a dog, we’ve covered our mattresses and pillows [with special cover-ings to reduce allergens], and we’ve put in wood flooring instead of carpets,” he explains.

At the same time, he is concerned that creating such a sterile environmentcould prevent his three-year-old son and eight-year-old daughter from building their own resistance to things that cause allergies. It’s a careful balancing act.

“If you’re allergic or asthmatic and you’re a parent, you might worry, ‘What is the impact of this disease on my children?’” he says. Though he is concerned that his children may develop asthma or allergies, he doesn’tlet those thoughts get the best of him.

With the care of a good doctor, proper medicine, and a healthy outlook,Huntley-Fenner has dealt with asthma head-on—and instead of anxiouslyawaiting another attack, he has pushed it into the background of his busy,fulfilling life.

“I know that asthma poses certain risks for me and my family,” he says,“but I won’t let it overshadow my life.”

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Part 5: How Can Allergies Be Treated and Prevented?

Diagnosing and treatingallergiesWhen a physician is evaluating a person for allergies, there areseveral steps involved. First, thepatient’s history is taken. Then,the patient is examined. Depend-ing on the patient’s symptoms,several tests might be done.Since some medications (espe-cially antihistamines) can affecttest results, a person should askthe health care provider whichmedications should be stoppeddays before the testing is to takeplace.

Skin (scratch or puncture)testing. In this test, a variety of substances that are commonto the region in which the personlives are evaluated. Tinyamounts of fluids containingallergens such as pollen, animaldander, dust mites, and moldsare placed just under the surfaceof the skin. Within 15–20 min-utes, swelling occurs at the siteof any substance to which theperson has an allergy. The sever-ity of the reaction can indicatethe person’s level of sensitivity.

Virtually painless, this form oftesting offers immediate resultsand almost no risk of seriousallergic reaction. This test isusually used to assess reactionsto respiratory allergens.

Intradermal testing. Thesetests are similar to scratch orpuncture tests, but are slightlymore involved. Tiny amounts ofallergens are injected under theskin. Intradermal tests are oftendone if the scratch or puncturetest results are not complete or useful.


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Blood (RAST) testing. In thesetests, a person’s blood is combinedwith an allergen to determinewhether any IgE antibodies react.If there is a reaction, there is likely an allergy to the tested substance. Although slightly moreexpensive than skin tests, this testis relatively painless, offers fastresults, and provides almost norisk of serious allergic reaction.Blood testing is often used to evaluate reactions to insects andmedications in people for whomskin testing is not an option.

Patch testing.For this type of test,allergen-specificadhesive patches areplaced on a person’sskin and left for 72hours. The sites thatshow swelling orredness indicate anallergic response.This form of testingis commonly used toassess reactions tometals and cosmeticadditives.

Provocative testing. This type of testing is also called challengetesting. Usually, the substance inquestion is administered in aneffort to provoke symptoms gradu-ally. A trace amount of the allergenmight be administered in anaerosol spray. The person’s reac-tion to the allergen indicates to

the physician both the nature of and the severity of the symptoms.Provocative testing can be uncom-fortable. Severe allergic reactionscan occur.

An infant’s sensitivity to a food oreven a food allergy might be diag-nosed at home first. If a parentknows that there is a family histo-ry of food allergies, there is a wayto avoid having an infant experi-ence full-blown symptoms. Bygradually introducing smallamounts of new foods—one at atime—parents can isolate a reac-tion. If a few foods are groupedtogether in a single meal, it is farmore difficult to figure out whichone is causing the reaction. If,however, a parent already suspectsthat a child has a food allergy, it isbest not to test this suspicion anyfurther at home. Safer testing canbe done in an allergist’s office.

A person can be treated for aller-gies, but not cured. The range oftreatment options provides somerelief for most people. As men-tioned earlier, one common form of treatment involves ongoingallergen immunotherapy (alsocalled allergy desensitization injections). Those who suffer fromreactions to airborne allergens and insect stings find this form of treatment quite beneficial. Over time, a series of injectionscontaining the offending allergensis given in an effort to build


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the immune system’s defensesagainst them.

When a person first begins aller-gen immunotherapy, a very dilut-ed form of the allergen compoundis given. Gradually, more of thesubstance is added to the injec-tion. Eventually, the allergistdetermines that the optimal dosehas been reached. The allergistcould also determine that the person is at risk of developing an allergic reaction if the injec-tions continue. Whatever thedetermination is, at this point the therapy ends.

The entire process of allergenimmunotherapy can last foryears. There is some evidencethat this type of therapy worksby tricking the immune system.As increased amounts of theallergen are injected, the immunesystem starts to produce a block-ing antibody (IgG). The IgG anti-body competes with the allergyantibodies (IgE) for the allergen,takes it over, and then does twothings that halt an allergic reac-tion: It prevents the mast cellsfrom activating and it stops therelease of histamines.

Most of the oral medications thatare used to treat allergies fallinto two categories: antihista-mines and decongestants.Antihistamines prevent a

histamine—a chemical that thebody produces during an allergicreaction—from taking effect.Antihistamines are availableover-the-counter in tablet and liquid form; they are also avail-able as tablets, liquids, and injec-tions with a prescription. Decon-gestants work by shrinkingblood vessels and decreasing fluidleakage so that nasal congestionis reduced. Both liquid and tabletforms are available as over-the-counter and prescribed medica-tions. Often, antihistamines anddecongestants are combined in asingle medication to address agreater number of symptoms.

For an acute allergic reactionthat involves a great deal of con-gestion, a physician might recom-mend a decongestant in the formof drops or a nose spray. Theover-the-counter form of medica-tion should not be used for morethan three or four consecutivedays. Otherwise, it can actuallyincrease nasal congestion. A pre-scription form of this medication

can be used for a longer periodwithout producing this side effect.

Nasal steroid inhalers or sprayscan offer fast relief by reducinginflammation and swelling, as wellas by slowing the rate at whichhistamines are released. Thesesprays deliver a very fine mistdirectly into the lining of the nose.They temporarily constrict theblood vessels in the swollen tissueswithin the nose. They also tem-porarily open a larger passage toallow for the free flow of air. Whenthe effects of the spray wear off,the swelling returns. Sometimes,the swelling has grown worse.When this happens, most peoplejust reuse the spray. Unfortu-nately, a series of brief periods ofrelief can lead to longer bouts ofcongestion. It is important to notethat decongestant nasal sprays canbe overused. If a person does over-use these sprays, his or her heartrate can increase and blood pres-sure can rise.

The good news is that most allergysymptoms can be treated easilyand safely. The bad news is that,on rare occasions, an allergic reac-tion can be deadly. As we discussedearlier, anaphylaxis is a severe,sometimes fatal, allergic reaction.It is usually treated with an injec-tion of epinephrine, and antihista-mines and steroids are also given.The sooner the allergic person getstreatment, the less severe the

symptoms will be. Epinephrine can stop the progression of ana-phylaxis; antihistamines andsteroids cannot. Antihistaminesand steroids should never be giveninstead of epinephrine, because,while they can help recovery, they cannot reverse the symptomsof anaphylaxis.

Often, a person who has a severefood allergy learns about it onlyafter exposure to the trigger. Suchexposure can happen as a result of breathing in or eating the sub-stance. After the symptoms aretreated, contact an allergist for follow-up care. The allergist canhelp determine what triggercaused the reaction. This is veryimportant in preventing anaphy-laxis from happening again.

Although triggers that are foodsmay be easy to avoid, it might betrickier when the allergen is a foodadditive. This is why it is crucialto be under a doctor’s care. If ana-phylaxis happens again, the per-son might already have an injec-tion of epinephrine handy. Usingthis medicine will keep symptomsunder control until the person canbe taken to a hospital. An allergistcan even offer treatments that canhelp build immunity to some trig-gers. For example, if anaphylaxisis triggered by insect stings, ongo-ing allergy shots can help buildtolerance to the venom.


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Here are some suggestions for what can be done to assistsomeone who is experiencing anaphylaxis:

1. Ahead of time, learn enoughabout the symptoms to recog-nize when the reaction is occurring.

2. Get medical help as soon aspossible.

3. Do not allow a person who isundergoing this type of reactionto drive.

4. Even if the person receivestreatment at the location wherethe reaction occurred, it is vitalthat he or she go to an emer-gency room, where the condi-tion can be monitored.

5. Make a note of what could have caused the reaction andwhat amount of time elapsedbetween exposure and reaction.Having this information couldhelp to prevent a future reaction.

Preventing and controlling allergiesFor most allergies, preventing orcontrolling symptoms requires afew simple steps. Depending onthe severity and frequency of thereaction, almost all symptoms canbe minimized by changes in envi-ronment and the person’s behav-ior. Once the triggers are known,

they should be avoided. Changesto the home, school, and workenvironments can significantlyreduce the person’s exposure to a variety of allergens.

The most important behavioralchange that a person can make tohelp prevent and control allergiesis to use all available methods oftreatment. Allergen immunother-apy can help build toleranceagainst specific allergens. Othermedications can help prevent orcontrol symptoms that do recur. A person who suffers from aller-gies can also improve his or hergeneral health by eating nutri-tious foods, exercising regularly,and getting enough rest.

At the very beginning of life andduring early childhood, measurescan be taken to help pre-vent some allergies.Researchers have knownfor some time that breastmilk is far more nutritiousfor infants than formula,cow’s milk, or soy milk.Studies show that infantswho are breast-fed are lesslikely to develop allergies toa variety of substances. Thelower incidence of allergy inchildren who were breast-fed might result from themother’s immunities beingtransferred to the childthrough the breast milk.

Another way to help lower the riskof allergy—specifically, peanut ornut allergy—involves not exposingchildren under the age of three topeanut products. Allergists believethat one reason that there are somany children in the UnitedStates with peanut allergies mightbe the extensive early exposurethey have to peanuts. Many youngAmerican children regularly eatfoods that contain peanuts orpeanut products.

In the case of life-threateningallergic reactions, preventionis possible only if the trigger canbe completely avoided. This is difficult to do, so additional measures must be taken to controlsymptoms. If a person has had an anaphylactic allergic reaction in the past, a physician might suggest carrying a supply of epinephrine at all times.

Regardless of whether the triggeris or is not known, the symptomscertainly are. Having a supply of a medication that can offer imme-diate relief will help get the symp-toms under control until the per-son can be taken to a hospital.Since this medication is given inthe form of an injection, the personwho carries it must know how toadminister it. However, becausethere is a possibility that the per-son having the reaction might beincapable of completing the injec-tion, a companion should alsoknow how to administer it.Another measure that can helpsave the life of a person known to have anaphylactic reactions is even easier to do: Have the per-son wear a medical bracelet thatindicates to medical personnel andothers the nature of the person’s allergic condition and any possible triggers.


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A Little Bit ofDiscomfort BringsReliefEvery day when Erminia Cardenas goes towork, she performs a simple test that canchange the lives of her patients.

Cardenas, who is a licensed vocational nurse inHouston, uses tiny prongs to prick the skin onher patients’ backs. There are 80 prongs in all,and each contains something different—fromgrass pollen to mold to cat dander.

The procedure is often the first step in unlocking the mystery of what iscausing her patients’ unexplained sneezing fits, watery eyes, and even difficulty in breathing—all symptoms of allergies. For Cardenas’s patients,the test is fascinating: Could the cause of all their problems be somethingas simple as the goose-feather-stuffed comforter on their bed, or could the culprit be a type of tree that lines the streets in their neighborhood?

If one or more of the pricks begin to itch, swell, or turn red, Cardenas hasthe answer. Even though the prong pricks cause a bit of discomfort, finallylearning the cause of their difficulties can be a huge relief to patients.

“We have one patient, a young man who works on the golf course at acountry club, who came to us because he had started sneezing every timehe went out on the course,” says Cardenas. “When we tested him, he wasallergic to all the grasses and tree pollens that surrounded him on the golfcourse—he was a mess, poor thing! He said, ‘I can’t give up my job,’ so weput him on shots and he’s doing very well.”

Cardenas, whose ancestors are Mexican, considers herself lucky becauseshe doesn’t have any allergies. Neither did her parents, which was fortu-nate, since they were migrant workers who spent a lot of time outdoors in the cotton fields. As a baby, Cardenas traveled with her parents to thefields. “If they ever had allergies, it wasn’t severe—not like what thepatients I see have,” she says.

Cardenas, continued on next page

But her son suffers from watery eyes and sneezing when the season changesevery year from summer to fall. The good news is that, with treatment, evenpeople who suffer from severe allergies can control their symptoms.

“Some of our patients can even give themselves shots at home, if their symp-toms are milder,” says Cardenas.

Cardenas, a mother of three who returned to nursing after taking time off to raise her children, sounds positively maternal when she talks about herpatients. She worries that many of the patients she sees—who range from airline pilots to lawyers to fellow nurses—have such demanding jobs that theirsymptoms can worsen because of the pressure. “Sometimes because they’re sostressed at work, they don’t take care of themselves,” she says. “I think stresscan aggravate allergies.”

So can the change of seasons—and Cardenas, who talked about her job on abeautiful March day when the spring’s first flowers were pushing through theground, knew she would be in for a busy time at work.

That’s just fine for Cardenas. After all, she knows that after patients come toher office and receive a proper diagnosis and treatment, they might actually be able to sit outside and take in nature’s beauty—without suffering from asneezing fit.


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