Food allergy hypersensitivity occurs in an allergic individual when the immune system reacts to food or something in the food, and causes symptoms similar to ragweed allergy or a beesting. This is different from food intolerance, a more general term that describes any abnormal reaction to a food or additive, and is not an allergy.

How common are food allergies? Studies are limited, however, in a study of Danish children, cow’s milk allergy was found to be 2.2%. In another study, approximately 4% of children up to age three were found to have food allergies. Studies in adults are even more limited, with as many as 2.4% having food allergy and intolerance.

Only a few foods cause most allergic reactions and symptoms usually occur within minutes of eating the food. These reactions occur in all age groups, and the individuals that react to foods usually have other allergies, asthma or eczema. In allergic infants and children, because the gastrointestinal system is also immature, food substances may also penetrate the system and cause reactions. And some studies suggest that exclusive breastfeeding may prevent some food allergies and eczema from occurring.

Can one outgrown food allergies? Interestingly, some, but not all, children and adults may outgrow milk, egg and wheat allergies if foods are avoided for at least 1-2 years. Peanut and shellfish allergies are more serious and last a lifetime, although some new research suggests that 20% of peanut allergic individuals may outgrow the allergy. In children, the foods commonly causing allergies include egg, milk, peanuts, tree nuts, and (less commonly) wheat, fish, soy, shrimp and peas. In adults, foods causing most allergies include fish, shellfish, tree nuts, peanuts and seeds (sesame). Food proteins are often resistant to heat and therefore cooking or boiling may not prevent the food from causing symptoms.

In adults and children, food allergy may cause a wide variety of symptoms and reasonable typical pollen allergies or a bee sting. For mild to moderate itching, runny nose, eye itching or hives, one can use one of the newer non-sedating antihistamines, such as Clarinex or Xyzal. Nasal steroids, such as Nasonex, are effective for nasal congestion or drainage. For mild coughing or wheezing, immediate use of a fast acting bronchodilator such as Proventil should help reduce and eliminate symptoms. More severe reactions may include chest tightness, wheezing, abdominal pain, nausea, vomiting, diarrhea, flushing, hives or swelling.