A case of prurigo pigmentosa treated with doxycycline

Abstract

Prurigo pigmentosa is a rare dermatosis with unknown etiology. It is characterized by the sudden development of erythematous papules that resolve leaving reticulated hyperpigmentation mainly on the trunk. Nearly 300 cases have been reported in Japan to date. A 17-year-old male came to our hospital with a 2-month history of pruritic eruption on the left clavicular area, back and nape. Before he visited our hospital, he was treated with topical corticosteroids and oral antihistamine but the eruption and the pruritus continued. We treated him with doxycycline, 200mg daily. Two weeks later, leaving brownish reticular pigmentation, the erythema and the pruritus disappeared. Over a year there has been no recurrence.