Trichotillomania Masked by Diffuse Alopecia Areata: A Case Report

An 11-year-old girl previously treated for tinea capitis presented a 3-month history of continuous decrease in hair density on the vertex, frontal, and parieto-temporal areas of the scalp. Hair pull test was negative. Trichoscopic findings showed black dots, micro-exclamation point hairs, regrowing vellus hair, and zigzag hairs. Histopathology showed CD3+ peribulbar lymphocytic infiltrates and occasional eosinophils around the anagen hair follicle consistent with a non-scarring alopecia. A diagnosis of diffuse alopecia areata was made. Patient was given methylprednisolone (0.5 mg/kg/day) for 2 weeks and noted marked increase in hair density except on focal areas of the scalp. Patient eventually admitted to occasional hair pulling. Trichoscopy revealed trichoptilosis, V-sign, tulip hairs, and multiple broken hairs of varying length while a second biopsy showed trichomalacia and pigment casts consistent with trichotillomania. In this case, where co-existence of alopecia areata and trichotillomania is considered to be uncommon, trichoscopy proved to be an important tool in differentiating hair disorders with similar presentation. Knowing key features of hair diseases can help elucidate the diagnosis when presented with an atypical case.