ABSTRACT
Cicatricial or scarring alopecias comprise a diverse group of scalp disorders that result in irreversible hair loss. All scarring alopecias are characterized clinically by a loss of follicular ostia and pathologically by a replacement of hair follicles with fibrous tissue. A basic knowledge of follicular anatomy is important in the understanding of cicatricial alopecias, because the location of the destructive process is crucial in determining the irreversibility of alopecia. Primary cicatricial alopecia refers to a group of idiopathic inflammatory diseases, characterized by a folliculocentric inflammatory process that ultimately destroys the hair follicle. Primary cicatricial alopecias are characterized by an inflammatory process affecting the upper, permanent portion of the follicles, particularly around the pluripotent stem cells of the bulge area, the sebaceous gland, and the infundibulum. Primary cicatricial alopecia most commonly affects the central and parietal scalp before progressing to other sites of the scalp.
