Peanut and tree nut allergy.

Allergy to peanut and tree nuts is a major worldwide health concern. The prevalence of these allergies may be increasing, but the reasons for these increases remain unclear. This group of foods accounts for a large proportion of severe and fatal food-allergic reactions. These allergies present most often during childhood but can occur at any age. Resolution is possible but uncommon, and frequent lifetime reactions caused by accidental ingestion are a serious problem. The major allergens of peanut and most tree nuts have been identified, allowing for insights into patient diagnoses, clinical outcomes, and potential future immunotherapies.