As an allergist, it is important to identify and empathize with patents, myself, had an adverse reaction to mango years ago. Biting into a fresh mango, my palms and feet began to itch, my skin began to swell and itch, and soon I looked like the Michelin Man's brother. That was not fun. I took some antihistamines and soon improved.

Adverse food reactions are unexpected reactions to ingested foods. This can be further subdivided into food allergies, which are immunologically mediated, and other reactions. Up to 30% of the population report an adverse reaction to food ingestion. Of these, only 6-8% of these are true food allergies in children under 5, and this drops to 3-4% in adults. Since only a few people have true food allergies, what are other causes of adverse food reactions? Lactose intolerance (not having lactase, the enzyme to break down milk sugar), stomach infections (food poisoning) and gastrointestinal reflux are some "food allergy" impostors.

This month I'll discuss immunoglobulin E (IgE) mediated reaction and next month non-IgE mediated food allergies. IgE are antibodies which are preformed in our body and react to contact with a specific protein. These reactions tend to present rapidly within minutes to hours and may be potentially life-threatening. Acute urticaria is an immediate skin reaction which may occur after an ingestion and manifests as raised, itchy and swollen skin. For children, milk, eggs, peanuts, nuts, soy and wheat tend to be the biggest offenders. For adults, fish, shellfish (so long Maine lobster and shrimp), tree nuts and peanuts are frequently implicated. Food additives have been reported, but are rare. Acute contact urticaria may occur for some people from only skin contact to foods. Raw meats, seafood, raw vegetables and fruits, milk, eggs, mustard, rice, and beer (say its not so) have been implicated in this form of urticaria.

Other symptoms of an acute urticarial response to food ingestion include: rhino conjunctivitis (runny eyes and nose), gastrointestinal anaphylaxis (nausea, belly pain, cramping, vomiting and diarrhea) and generalized anaphylaxis. A word about this last one, it can be nasty.

Generalized anaphylaxis (GA) is a severe allergic response effecting the skin, respiratory and cardiovascular systems. In the severest forms, a person experiencing GA may develop very low blood pressure, cardiac arrhythmias and even die. Food allergy has been estimated to account for up to one half of all anaphylaxis cases in the emergency room. Common offenders are peanuts, tree nuts, fish and shellfish. My nephew has a walnut allergy and all foods must be devoid of walnuts or his life may be in danger. Treatment for the above includes fluid, fluid, and more fluid, antihistamines and epinephrin. In severe cases like my nephew, Epipens (epinephrin syringes) and antihistamines have to be available at all times.

Lastly I would like to mention two related diseases. Atopic dermatitis is a chronic skin disorder beginning in early infancy. It may be associated with asthma and allergic rhinitis (runny nose). With this problem, eating certain foods produces a rash. Systematically eliminating foods from a child's diet may be able to help eliminate this problem. And finally, asthma may be related to food. This typically is seen in people working in the food industry developing asthma after repeated inhaled exposure. "Bakers lung" is an example of an IgE-mediated allergy to inhaled wheat protein.

As I prepared for this article, many friends suggested specific topics to discuss: celiac sprue, peanut allergies and even garlic! I realized next month I will need to continue the details of this problem.

Dr. Jeffrey Rehm, father of three, is a pulmonologist at both Mary Washington Hospital and 521 Park Hill Drive. Phone is (540)899-1615.