Effect of topically applied capsaicin on pruritus in patients with atopic dermatitis

The neuropeptide substance P has been implicated in the pathophysiology of pruritus. Capsaicin, the pungent agent in red pepper, is known as a potent substance P depletor. Therefore, the influence of capsaicin on pruritus was studied in ten patients suffering from atopic dermatitis. The patients applied 0.05% capsaicin cream four times daily to one arm for 3 weeks in an open left versus right comparison. Every week skin lesions were evaluated by a physician, and pruritus was assessed by the patients. Four out of ten patients reported a marked relief of pruritus in the capsaicin-treated area only. A relief of pruritus by both capsaicin and vehicle was reported by two patients. Capsaicin was of no benefit in two patients. All patients reported a transient burning sensation after application of capsaicin, which gave reason to discontinue capsaicin treatment in two cases. We conclude that for some patients with atopic dermatitis, capsaicin can be helpful in reducing pruritus.