Quantitative Morphmeetric And Histochemical Analyis Of Hair Jollicles In Alopecia Areata

Abstract

Alopecia areata is a common disease of the hair follicle characterized by the appearance of patchy areas of hair loss leaving a smooth and non- scarre9 scalp. The disorder is potentially reversible and is characterized by either limited patchy hair loss (alopecia ar ata), loss of all scalp hair (alopecia totalis) or all body hair (alope<?ia universalis).

Although several hypotheses have been proposed, the exact pathogenesis of hair loss is not clear. Among the many factors which appear to be implicated are the patient's genetic constitution, on-specific immune and anagen-specific autoimmune reactions and possibly emotional stress.

The histologic features of alopecia areata vary with the stage of the lesion. Active patches demonstrate peribulbar lympho id infiltrate, a reduction in the anagen/ telogen ratio and miniaturized dystrophic hairs. In later stages, a reduction in the anagen/telogen ratio, miniaturized hairs, and many fibrous tracts, some with lymphoid cells or pigment incontinence are seen.

Diagnostic features of alopecia areata include a peribulbar lymphocytic infiltrate, and significantly decreased terminal hairs, increased follicular stelae, decreased anagen and increased telogen and often catagen hairs, and increased vellus hairs.