Patchy hair loss in an otherwise healthy man.

What diagnoses should be considered? The most important diagnosis to consider is alopecia areata. This is an immune-mediated form of hair loss that most commonly affects the scalp, but it can affect any hair-bearing site. It can occur in any ethnic group, both sexes and at any age, with an estimated lifetime risk of 1.7% in the general population. Other diagnoses to consider include tinea capitis, trichotillomania and cicatricial (scarring) alopecia.