Both food allergies and eosinophilic esophagitis are on the rise, and the two conditions have a strong association. Esophagitis is an inflammatory condition of the esophagus. It has several causes: acid reflux, infection by viruses or fungi, medication that gets stuck in the throat, radiation (as in therapy for lung cancer), and allergy. Eosinophilic esophagitis is a condition characterized by the presence of abnormal numbers of a specific type of white blood cells (eosinophils) in the throat. At least 50 percent of patients with this condition also have another allergic condition, such as asthma, hay fever, or dermatitis (skin rash).
The symptoms of esophagitis include:
1. Difficulty swallowing, especially for solid food
2. Nausea and vomiting
3. Chest pain for adults, abdominal pain for children
4. Failure to thrive (for children)
5. Food impaction. This is the most serious symptom, when food gets stuck in the throat and blocks swallowing. The patient feels chest pain that mimics heart attack, and spits up saliva that cannot be swallowed. The treatment is endoscopic removal of the food by a doctor
A recent article in the Cleveland Clinic Journal of Medicine reports that food allergies appear to be the most likely cause of eosinophilic esophagitis, but it is a challenge to identify specific food triggers for some patients. Skin prick tests have been able to identify common food allergies for about two-thirds of eosinophilic esophagitis patients. Atopy patch testing is more effective for some patients. In this method, a small quantity of food is placed on the skin, and the skin reaction is evaluated after a set time.
A double-blind, placebo-controlled oral food challenge is the gold standard for diagnosing food allergies. The food to be tested is hidden in other foods or in capsules so that neither doctor nor patient knows which is the test food and which is the placebo. Unfortunately, this poses the risk of severe allergic reaction, so skin tests and blood tests are preferred. The blood test is called radioallergosorbent testing (RAST).
The most common food allergies for children are milk, egg, and peanut. For adults, the most common are tree nuts, fish, and shellfish. Food allergies affect an estimated 6 to 8 percent of young children in the United States, and 3 to 4 percent of adults.
References:
Hong S et al, “Food allergy and eosinophilic esophagitis: Learning what to avoid”, Cleveland Clinic Journal of Medicine 2010 January; 77(1): 51-59.
More information online:
http://www.medicinenet.com/eosinophilic_esophagitis/article.htm
Linda Fugate is a scientist and writer in Austin, Texas. She has a Ph.D. in Physics and an M.S. in Macromolecular Science and Engineering. Her background includes academic and industrial research in materials science. She currently writes song lyrics and health articles.