Involvement of Cell Adhesion and Activation Molecules in the Pathogenesis of Erythema Dyschromicum Perstans (Ashy Dermatitis)

Abstract

To assess the expression of several cell adhesion and lymphocyte activation molecules in erythema dyschromicum perstans lesions, and to evaluate the effect of clofazimine therapy on the expression of these molecules. A prospective study. Skin biopsy samples were obtained from patients before and after 3 months of clofazimine therapy, and the expression of cell adhesion and activation molecules was assessed by an immunohistochemical technique. This study was performed in a clinical referral center and an immunology research laboratory. We studied 6 patients with erythema dyschromicum perstans. A diagnosis was made on the basis of clinical and histological criteria. Two patients discontinued participation in the study: one because of adverse effects and the other for unknown reasons. Patients were treated with clofazimine, 100 mg/d, for 3 months. Expression of cell adhesion and lymphocyte activation molecules in skin biopsy specimens before and after clofazimine therapy. Before clofazimine therapy, we detected a noticeable expression of intercellular adhesion molecule 1 and major histocompatibility complex class II molecules (HLA-DR) in the keratinocyte basal cell layer. In addition, CD36, a thrombospondin receptor that is not expressed by normal skin, was detected in the strata spinosum and granulosum. The dermal cell infiltrate expressed the activation molecule AIM/CD69 and the cytotoxic cell marker CD94. After clofazimine therapy, the expression of intercellular adhesion molecule 1 and HLA-DR disappeared, as well as the mononuclear cell infiltrate. Our results suggest that some cell adhesion and activation molecules are involved in the pathogenesis of erythema dyschromicum perstans. Clofazimine appears to have an important effect on the inflammatory phenomenon of erythema dyschromicum perstans.