Update on primary cicatricial alopecias.

UNLABELLED The cicatricial alopecias encompass a diverse group of disorders characterized by permanent destruction of the hair follicle and irreversible hair loss. Destruction of the hair follicle can result from primary, folliculocentric disease or as a secondary result. This article focuses on the former, or primary cicatricial alopecias. The cause and pathogenesis of many of these disorders are largely unknown. Although unique clinicopathologic features allow for accurate diagnosis in some cases, diagnostic certainty is often elusive and reflects the limits of present understanding. Classification of the primary cicatricial alopecias on the basis of pathology provides a diagnostic and investigational framework and, it is hoped, will facilitate future enlightenment. Details of classification, etiopathogenesis, clinicopathologic features, differential diagnosis, and practical management of the primary cicatricial alopecias will be discussed. LEARNING OBJECTIVES Upon completion of this learning activity, participants should be familiar with the following aspects of the primary cicatricial alopecias: (1) the new, consensus-issued classification scheme, (2) current understanding about etiopathogenesis, (3) salient clinicopathologic features, (4) differential diagnosis, and (5) therapeutic management.