Dermoscopic clues to distinguish trichotillomania from patchy alopecia areata

BACKGROUND: Trichotillomania and patchy alopecia areata have similar clinical and dermoscopic features. OBSERVATIONS: In trichotillomania, dermoscopy shows decreased hair density, short vellus hair, broken hairs with different shaft lengths, coiled hairs, short vellus hair, trichoptilosis, sparse yellow dots, which may or may not contain black dots and no exclamation mark hairs. CONCLUSIONS: In the case of patchy alopecia and broken hairs, the absence of exclamation mark hairs suggests a diagnosis of trichotillomania. On the other hand, the finding of yellow dots without black dots does not exclude it.