Pimecrolimus in dermatology: atopic dermatitis and beyond.

Pimecrolimus is a calcineurin inhibitor developed for the topical therapy of inflammatory skin diseases, particularly atopic dermatitis (AD). Pimecrolimus selectively targets T cells and mast cells. Pimecrolimus inhibits T-cell proliferation, as well as production and release of interleukin-2 (IL-2), IL-4, interferon-gamma and tumour necrosis factor-alpha. Moreover, pimecrolimus inhibits mast cell degranulation. In contrast to tacrolimus, pimecrolimus has no effects on the differentiation, maturation and functions of dendritic cells. In contrast to corticosteroids, pimecrolimus does not affect endothelial cells and fibroblasts and does not induce skin atrophy. Given the low capacity of pimecrolimus to permeate through the skin, it has a very low risk of systemic exposure and subsequent systemic side-effects. In different randomised controlled trials, topical pimecrolimus as cream 1% (Elidel) has been shown to be effective, well tolerated and safe in both adults and children with mild to moderate AD. In addition, pimecrolimus has been successfully used in inflammatory skin diseases other than AD, including seborrheic dermatitis, intertriginous psoriasis, lichen planus and cutaneous lupus erythematosus.