And while we're on the subject of allergies....

Perhaps there is no cause of sudden death as distressing as that due to anaphylaxis, also called anaphylactic shock--allergic reactions that produce such severe swelling of the air passages that suffocation and death occur, often within minutes. The allergic reaction may be to a drug such as penicillin, an insect sting, or even some foods. Sadly, most anaphylactic deaths are readily preventable--but only if an injection of epinephrine (adrenaline) is promptly given.

Anaphylaxis, like other forms of allergy, can occur when the victim has been sensitized beforehand by the offending allergen. On the other hand, an allergic reaction can also be induced the first time one is exposed to a particular allergen. If subsequent exposure to a given allergen produces even the mildest symptom of allergy--such as a skin rash, asthma, or nausea--the patient should beware of future exposure to anything with allergic potential.

Allergic reactions to food are common, but anaphylaxis among persons with food allergies is rare. However, hundreds of children in this country die needlessly each year of allergies to hidden ingredients in food, according to a study that was reported last August in The New England Journal of Medicine. This study also pointed out that adults, including some doctors, fail to treat the allergic reaction as a medical emergency.

The study involved 13 children, six of whom died. These six were known to have allergies, five of them having previously reacted to the particular foods that finally killed them. However, none of the six, nor their parents, were aware that the food they had eaten contained the fatal ingredient.

Three of the patients were allergic to peanuts, two to other nuts, and one to eggs. The foods they ate included a cupcake, a sandwich, a hamburger roll, and candy. All six were under active treatment for asthma, allergic rhinitis, and atopic (allergic) dermatitis. One had received epinephrine and corticosteroids for an allergic reaction to food two weeks before.

In five of the cases, the reactions took place in public places, four at school, and one at a fair. All five had oral and abdominal symptoms (itching or tingling in the mouth, tightness in the throat, abdominal cramps, and vomiting). The sixth patient, a two-year-old, was reported to have been irritable after ingesting the fatal food.

Symptoms began three to 30 minutes after ingesting the food and became severe 20 minutes to two-and-a-half hours later. Although self-injectable epinephrine had been prescribed for three of the six children, none had it available at the time of the reaction. Although symptoms developed almost immediately in all six cases, four of the six had mild symptoms for an hour or more before severe respiratory distress began. None of the six received epinephrine before the onset of severe breathing difficulties.

On the other hand, the other seven children in the study who did not die received epinephrine before or within five minutes of the development of severe symptoms.

It appears from other studies that the frequency of fatal and near-fatal food-induced anaphylactic reactions has increased in recent years. Much of this seems to be due to the increasing use of protein additives in commercially prepared foods. The presence of these proteins is not always noted on the label in such a way for even the most careful parent to identify the presence of a known allergen and avoid giving the food to the child.

The authors of the study recommend that children who have had a severe allergic reaction to any food be taught to use and always have epinephrine at hand. Those responsible for them at school, at home, or elsewhere should likewise be trained to recognize the problem and promptly administer the drug.

The EpiPen Epinephrine Auto-Injector is recommended for this purpose. Marketed by Center Laboratories of Port Washington, New York, the device delivers a premeasured dose of epinephrine into the thigh muscle. Two models are available--the EpiPen (0.3 mg) for adolescents and adults and the EpiPen Jr. (0.15 mg) for younger children.

Anyone who has experienced an allergic reaction to food, insect bites or drugs should ask his or her physician to prescribe the device. At a cost of about $30, the unit should retain its potency for years. Each unit contains a registration form to be mailed to Center Laboratories, who will then notify the purchaser before the expiration date.

The Auto-Injector design is that issued for military personnel to deliver antidotes for nerve gas. To work the device, simply remove the cap, place the tip against the outer thigh, and push, holding it in place for several seconds before discarding it. A reusable EpiPen Trainer, containing neither drug nor needle, is available to physicians to teach patients how to use it.