Expression of adhesion molecules in atopic dermatitis is reduced by tacrolimus, but not by hydrocortisone butyrate: a randomized immunohistochemical study.

Topical tacrolimus represents an effective and well-tolerated treatment for atopic dermatitis (AD). Its known effects include reduced production of proinflammatory cytokines and reduced chemokine gradient. We performed lesional skin biopsies on adult patients affected by moderate-to-severe AD. Then, patients were randomized to receive local treatment with tacrolimus ointment 0.1% and hydrocortisone butyrate ointment 1%. On the 21st day of treatment, another skin specimen was taken. Nine patients treated with tacrolimus and seven treated with hydrocortisone successfully concluded the trial. By immunohistochemistry (alkaline phosphatase/antialkaline phosphatase method), we demonstrated that endothelial leucocyte adhesion molecule (ELAM)-1, vascular cell adhesion molecule (VCAM)-1 and intercellular adhesion molecule (ICAM)-1 showed different intensities and patterns of expression in untreated AD lesions. Tacrolimus-treated specimens featured a significant reduction of the expression of ELAM-1, VCAM-1 and ICAM-1, while hydrocortisone-treated lesions did not. Inhibition of adhesion molecule expression may represent another selective mechanism of action of topical tacrolimus in AD.