Anaphylaxis is a rare but potentially life-threatening reaction to an allergen or other trigger. Knowing its signs is essential for immediate treatment when symptoms can be reversed most easily. The most common triggers of anaphylaxis are foods, drugs and insect stings. Less common triggers are latex-and even exercise.
Carol has a known allergy to nuts and carefully avoids them. Yet while playing cards at a birthday party one day, she suddenly develops swollen lips and eyelids and feels a “tickling” in her throat. As it turns out, another guest at the party had eaten nuts just before joining the card game, and had transferred traces of the nuts from her fingers to the cards. Carol immediately takes a liquid antihistamine which suppresses allergic responses. Gradually, her symptoms go away.
Nuts, along with milk, eggs, wheat and shellfish, are the most common foods that trigger anaphylaxis. As Carol’s case illustrates, even a slight trace can cause problems in a susceptible individual.
One or all of the signs and symptoms of anaphylaxis may be present. Symptoms can include tissue swelling and/or hives, breathing difficulty, hoarseness and swelling of throat tissues, a drop in blood pressure and shock. Usually, the more rapidly the symptoms progress, the more serious the problem.
To pinpoint which food has caused an anaphylactic reaction, an allergist first takes a careful medical history. Sometimes this alone can identify the culprit. In other cases, the physician may order allergy tests and ask the patient to keep a detailed food diary to help determine the trigger or triggers. In more difficult cases, the allergist may order a “food challenge” test. In this test, the patient is exposed to very small amounts of various foods. If one of them provokes signs of anaphylaxis, the mystery is solved. A physician or nurse is prepared to immediately treat the reaction and directly observes the patient throughout the test.
Once a food allergen is identified, the patient must take great pains to avoid eating it again. That includes asking about all of the ingredients in any food or dish that may contain it. Children are especially at risk of encountering a problem food when they are away from home. Older children must be trained to ask the ingredients of any foods they eat. For younger children, the child-care provider or other adult who supervises them must accept that responsibility. As Carol’s experience shows, however, exposure can’t always be prevented. That’s why anyone who experiences anaphylaxis must have the proper medications on hand to treat it.
The drugs available today have vastly improved physicians’ ability to diagnose and treat diseases. Unfortunately, some of these agents (in rare cases) can trigger anaphylaxis. Antibiotics, especially penicillin, lead the list of offenders. As with food allergens, the best precaution for people who have experienced any sign of allergic reaction to a particular medication is to avoid it in the future. If the troublesome drug is essential for treatment, an allergist can run further tests to determine how serious the patient’s allergy is. The allergist may determine that the patient can safely take the drug.
Many allergy sufferers receive regular immunotherapy in which they are given injections of the allergens in order to help overcome their allergies to the substances. These doses of allergens are a type of “drug,” therefore both physicians and patients must be alert to the risk of anaphylactic shock inherent in immunotherapy. Patients should remain in the physician’s office under the direct observation of a trained health-care provider for at least 20 minutes after receiving immunotherapy, when an anaphylactic reaction is most likely to occur.
Although rare, bee or wasp stings can trigger life-threatening anaphylactic reactions in susceptible people. If a person develops signs of anaphylactic shock following an insect sting, he or she will require immediate medical attention. Emergency room personnel are well trained to recognize and treat insect sting reactions. There is now an effective immunotherapy which can reduce reactions to any subsequent stings.
Scott is undergoing another in a long series of operations for spina bifida, a congenital defect of the spine. Suddenly, his blood pressure drops, he begins wheezing and he breaks out in hives. The surgeon halts the operation and the anesthesiologist begins administering drugs to treat anaphylaxis. Scott’s symptoms disappear. The latex in the surgeon’s gloves had caused an allergic reaction.
This unusual but potentially serious reaction occurs most typically in patients who have undergone many operations, as well as in health-care providers who use latex gloves often. The best treatment for latex allergy is to avoid latex. That means warning your dentist, dental hygienist, doctor and any other health-care professional to use non-latex gloves when examining or treating you. It also means learning about the range of products that contain latex, from balloons to rubber bands, and eliminating them from your home and work area.
As the aerobics class she is leading ends, Missy develops hives and abdominal pain. She takes an antihistamine for the hives and soon feels better. Two weeks later, after a second episode, she sees her doctor. In response to the physician’s questions, Missy recalls having had a snack before each of the two episodes. Missy is instructed to avoid eating for at least four hours before exercise. She does so and has no further problems.
Exercise-induced anaphylaxis is rare but frightening. It can occur at any level of exercise, whether or not food has been eaten right beforehand. It can be predictable-or unpredictable. Therefore, anyone who has experienced an episode of exercise-induced anaphylaxis must keep an epinephrine kit containing a syringe of the hormone readily available during workouts and should exercise only with a partner or in a supervised setting.
Jan had just finished dinner when she began to feel “funny.” The sensation reminded her of how she had felt during an anaphylactic reaction she had experienced several months prior. Though she had an epinephrine kit, she did not feel she could inject herself. She called a neighbor, who gave her the injection. Jan began to feel faint, but did not develop hives, difficulty speaking or wheezing. Taken to an emergency room, she received more epinephrine and other medications and fully recovered.
Epinephrine is the cornerstone of anaphylaxis treatment. Several types of epinephrine kits are available. EpiPen is a preloaded syringe that is pushed against the skin and delivers epinephrine. The needle is not exposed and is convenient to use. Depending on the severity of the syndrome, treatment may also include antihistamines, intravenous fluids, bronchodilators to relax lung spasms, or corticosteroids to reverse tissue swelling and other inflammatory reactions.
Education is paramount. Susceptible people need to know both how to avoid triggers and how to recognize the earliest warning symptoms of anaphylaxis so that, in case of an inadvertent exposure, treatment can be prompt. As Jan’s case illustrates, the sooner treatment starts, the better the results. Because Jan received treatment at the earliest hint of anaphylaxis, her reaction never became serious. Though frightening, anaphylaxis often can be prevented through careful diagnosis and avoidance of offending allergens. Moreover, everyone can learn to recognize the earliest signs of the syndrome, when prompt treatment can best prevent serious problems.