CICATRICIAL ALOPECIA

Scarring alopecias are of diverse etiology and pathogenesis. They may be histologically classified as primary or secondary, depending on inv olvement of reticular dermis. The most important primary scarring alop ecias include pseudopelade, lichen planopilaris, and diffuse scarring of the vertex in African-Americans. The most important secondary scarr ing alopecias include folliculitis decalvans and late-stage lupus eryt hematosus.