Concentric or Targetoid Regrowth in Alopecia Areata

The document discusses a case of alopecia areata (AA) in a 33-year-old man who exhibited a unique pattern of hair regrowth. The patient had been treated with topical corticosteroids, minoxidil, and intralesional corticosteroids for a single plaque of AA in the occipital region. During follow-up, annular areas of black hair growth were observed at the vertex and occipital region, while the initial plaque had spread to the parietal region, creating a targetoid pattern. Dermoscopy showed yellow and black dots and isolated fragmented hairs. A diagnosis of concentric or targetoid regrowth in AA was made, and complete hair regrowth was achieved after a cycle of oral corticosteroids. The article suggests that this pattern of regrowth, which can occur after various treatments or even spontaneously, may be underdiagnosed and should be recognized to avoid confusion with other types of alopecia. The authors also discuss other unusual forms of AA presentation and the need for differential diagnosis from other disorders with similar annular alopecia patterns.