Efficacy of Topical Pimecrolimus in the Treatment of Pityriasis Alba: A Randomized Placebo-controlled Trial

Background and Rationale: Pityriasis alba (PA) is a common benign skin disorder, that usually affects children and adolescents of darker phototypes. PA usually manifests as erythematous lesions followed by smooth scales with residual characteristic pruritic or non-pruritic ill-defined hypopigmented patches, that typically occur on the upper part of the body, especially the face. A history of atopic dermatitis is a well-known risk factor, and PA may be a minor manifestation of atopic dermatitis, although it can occur in nonatopic individuals as well. It is thought to represent nonspecific dermatitis with residual post-inflammatory hypopigmentation. Sun exposure is a triggering and accentuating factor. PA is a common reason for dermatologic consultation due to its chronic course, frequent relapses and cosmetic appearance. Spontaneous healing occurs in several months to few years, therefore impacting the quality of life. Emollients and mild-potency topical steroids are the mainstay of treatment, with a potential risk of skin atrophy and hypopigmentation. Pimecrolimus is a topical calcineurin inhibitor that prevents T-cell activation, approved for the treatment of atopic dermatitis, and proved efficacious for seborrheic dermatitis, without having the potential adverse effects of topical corticosteroids. Tacrolimus 0.1% ointment, another calcineurin inhibitor is an effective and safe treatment for PA, a similar efficacy of calcitriol and tacrolimus was shown after 9 weeks of treatment. An exploratory study evaluated the efficacy of pimecrolimus cream in the treatment of PA. To the best of our knowledge there is no randomized placebo-controlled trial in the literature proving the efficacy of pimecrolimus in PA. Objective: To evaluate the effect of topical pimecrolimus in the treatment of treatment of PA Hypothesis: Pimecrolimus is an efficacious, well-tolerated and safe treatment for pityriasis alba. Trial design: A randomized placebo-controlled double blinded trial establishing the superiority of topical pimecrolimus 1% over placebo.