Linear alopecic patches in a child: An unusual presentation
A 10-year-old girl presented with patches of hair loss involving the midline and the crown area of the scalp for the past 5 months. There was no history of associated pruritis or hair loss in any other areas. Personal and family history were unremarkable.

On examination, the patient had 3 × 10 cm linear patch of nonscarring alopecia on the midline of scalp. Another similar patch of size around 2 × 10 cm was present 3 cm lateral and parallel to the previous patch. There was no redness or scaling. Hair pull test was negative along the edges of the patch and no exclamation mark hair was observed.

Polarized dermoscopy was done with a handheld Dino-Lite DermaScope and showed hair of different lengths with broken shafts, numerous black dots, perifollicular hemorrhage, flame-shaped hair, vellus hair, V-sign, and pigtail hair. Biochemical tests including thyroid function tests were within normal limits. Punch biopsy was performed from the edge of the lesion, which revealed thickened and wrinkled fibrous root sheaths with abundant deposits of melanin pigment, extravasated red blood cells within the hair matrix, and trichomalacia. Although the clinical picture was atypical, a diagnosis of trichotillomania (TTM) was made based on the classical histopathology and dermoscopic findings.

Source: Indian dermatology journal online

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