Alopecia Areata

Alopecia means hair loss; it is a clinical finding rather than one single disease. The clinical focus is alopecia areata (AA), an autoimmune disorder in which T cells target hair follicles. The follicle is attacked during the hair-growth cycle, but it is not usually destroyed. That is why AA produces nonscarring loss: the skin may look smooth and bare, while follicular openings remain visible and regrowth remains possible. The usual presentation is one or more sharply defined patches of scalp hair loss. Eyebrows, eyelashes, beard areas, and other hair-bearing sites can also be involved. The extent of loss and the speed at which it develops matter more than the size of one isolated patch. AA is not a wound. Missing hair does not create a wound bed, exudate, tissue depth, or a need for routine wound measurements, dressings, ankle-brachial index testing, or wound cultures. Those assessments belong to different clinical problems and can distract from the findings that establish the pattern of AA.