A number of different symptoms can be associated with IgE-mediated food allergies. The symptoms that occur during a food-allergic reaction will not always be the same.

This website is not intended to be clinically oriented. Thus, we will provide links to reliable medical websites that should be consulted as the primary source of this type of information.

The nature of the symptoms and their severity depend upon several factors:

• the individual,
• amount of the offending food ingested,
• tissue receptors that are affected,
• length of time since the previous exposure.

Some individuals tend to develop only mild symptoms while others may experience much more severe manifestations.

The symptoms of IgE-mediated reactions can involve the gastrointestinal tract, skin, or respiratory tract. Gastrointestinal and cutaneous symptoms are among the more common manifestations of IgE-mediated food allergies.

• Common gastrointestinal symptoms include abdominal cramps, nausea, vomiting, and diarrhea. Of course, all of the GI symptoms have multiple possible causes and can occur in other foodborne disease. The diagnosis of food allergy based upon the appearance of gastrointestinal symptoms alone can be quite difficult.
   
• Cutaneous symptoms will include hives, itching, and eczema or dermatitis. Dermatitis is an especially common manifestation in early childhood. About 40% of cases of dermatitis in young infants may involve food allergies.

• Respiratory symptoms are much less commonly encountered in food allergies. However, individuals with respiratory manifestations of their food allergies can be more likely to experience severe and life-threatening reactions (asthma, laryngeal edema). Mild respiratory symptoms (rhinitis, rhinoconjuncitivitis) are much more likely to be encountered with exposure to environmental allergens such as pollens or animal danders that are airborne and inhaled directly into the respiratory tract. While these mild respiratory symptoms are mostly annoying, those few food-allergic individuals who experience serious respiratory manifestations (asthma, laryngeal edema) in association with the inadvertent ingestion of the offending food are most likely to be at risk for life-threatening episodes.

• Anaphylactic shock is the most severe manifestation of IgE-mediated food allergy. Anaphylactic shock can involve multiple organ systems (gastrointestinal, respiratory, cutaneous, and cardiovascular) and numerous symptoms. Death can ensue from severe hypotension coupled with respiratory and cardiovascular complications.

Severe Symptoms

Some symptoms of food allergy are potentially quite severe. As noted above, anaphylactic shock is the most severe. But, asthma and laryngeal edema can also be very serious symptoms. Fatal reactions can and do occur. Anaphylactic shock is a common cause of death in these fatalities.

Comparatively few individuals are susceptible to suffering such severe reactions upon food ingestion. The inadvertent ingestion of allergenic foods has resulted in deaths. Deaths have occurred with most of the common allergenic foods (all of the Big 8 except wheat), although peanuts, tree nuts, and crustacea seem to be more frequently implicated in severe food allergies than some of the other commonly allergenic foods.

The prevalence of severe allergic reactions to foods is rather uncertain. The number of deaths occurring from IgE-mediated food allergies in the U.S. (or in other countries) is somewhat debatable. Some experts have estimated that 100 – 200 deaths occur each year in the U.S. However, many of these deaths are not recorded as food allergy deaths because of the nature of the reporting systems used by the U.S. health care community. Certainly, fatal reactions can and do occur. The precise number may not be as important as the realization that fatal food-allergic reactions are preventable.