Peanut challenge: a retrospective study of 140 patients

Abstract

Given the poor positive predictive value and specificity of PST, a peanut challenge is usually required to diagnose peanut allergy with certainty when the PST is positive. In cases of a clear history of anaphylaxis to peanut and a positive PST, challenges are unwarranted. When the history is strongly suggestive and the PST is borderline positive, i.e. 3 or 4 mm, peanut challenge is generally necessary to confirm the diagnosis. Given the excellent negative predictive value and sensitivity of PST, a blinded peanut challenge is usually unnecessary in the context of a negative PST except for patients with a history strongly suggestive of immediate hypersensitivity. These patients should be individually assessed for the need to undergo a blinded challenge. The peanut challenge is a useful and safe diagnostic tool when performed by qualified personnel under appropriate conditions.