Peanuts, along with milk and eggs, have been documented to account for approximately 80% of adverse reactions to foods in patients with atopic dermatitis. Over the past 3 years, we have evaluated 71 patients with atopic dermatitis, ranging from mild to severe in nature. These patients were initially evaluated by allergy prick skin testing and when appropriate had double-blind placebo-controlled food challenges done. Thirty-nine (55%) patients had a positive prick skin test to one of the foods tested. There were 80 food challenges performed with peanut, accounting for 12 (32%) of the 38 positive challenges in 23 (31%) patients. As in earlier studies, patients developed skin (97%), respiratory (55%), and gastrointestinal (32%) symptoms during the challenge. Of the five patients with histories of prior anaphylactic reactions four (80%) were to peanut. These studies indicate that children with all degrees of atopic dermatitis may benefit from evaluation for food hypersensitivity. They also show that peanut is a major food protein responsible for these reactions.