A case of lichen planopilaris associated with lichen planus following Blaschko lines successfully treated with topical corticosteroid

Lichen planopilaris (LPP) is characterized by erythematous, keratotic follicular papules and cicatricial alopecia. LPP, the most common cause of cicatricial alopecia, is usually seen in women and causes significant psychosocial morbidity. We describe here a 42-year-old woman with a 6-month history of hair loss accompanied by itching on the scalp. Dermatological examination revealed patchy cicatricial alopecia in the vertex and band-like purple flat patches and plaques following the Blaschko lines on the right half of the body, together with post-inflammatory hyperpigmentation. Histopathological examination of the scalp biopsy was consistent with LPP, while thigh biopsy was consistent with lichen planus. With the histopathological and clinical evidence, our patient was evaluated as LPP associated with LP and successfully treated with topical corticosteroid. A few LPP and LP cases following the Blaschko lines have previously been reported separately. However, LPP, together with LP following Blaschko lines, have not been reported in the same patient.