Food Allergies: Diagnosis, Treatment, and Prevention.

In the United States, approximately 2% to 3% of adults and 8% of children have a food allergy. Allergic reactions range from minor pruritus to life-threatening anaphylaxis. These allergies often lead to significant anxiety and costs for patients and caregivers. Common food allergies include peanuts, cow's milk, shellfish, tree nuts, egg, fish, soy, and wheat. Peanut allergy, the most common, is the leading cause of life-threatening anaphylaxis. Children with asthma, allergic rhinitis, atopic dermatitis, or an allergy to insect venom, medications, or latex are at an increased risk of developing food allergies. Diagnosis of food allergy starts with a detailed, allergy-focused history. Serum immunoglobulin E and skin prick testing provide reliable information regarding food allergy diagnoses. Primary treatment involves elimination of the offending food from the diet. Prevention strategies proven to decrease the risk of developing a food allergy include restricting exposure to cow's milk in the first three days of life and early sequential exposure to allergenic foods starting between four and six months of age. Exclusive breastfeeding for three to four months reduces the likelihood of developing eczema and asthma but does not reduce development of food allergies. Most children eventually outgrow allergies to cow's milk, egg, soy, and wheat. However, allergies to tree nuts, peanuts, and shellfish are more likely to be lifelong.