Prurigo pigmentosa and diabetes: A case report

Abstract

Sir, Prurigo pigmentosa is a rare inflammatory disease first reported in 1971 by Nagashima et al. as a “peculiar pruriginous dermatosis with gross reticular pigmentation” in Japan [1], where the largest number of such cases have been described, with only several cases having been described elsewhere. Herein, we report a new case of prurigo pigmentosa. A 32-year-old Moroccan female presented at our dermatology department with a several-week-old history of pruritic eruptions on the chest, abdomen, lumbosacral area, and neck. According to the patient, the onset was marked by itchy papules coalescing to plaques, secondarily becoming hyperpigmented reticulated macules. The patient was treated with antifungal drugs without improvement. Additionally, the patient had recently been diagnosed with type II diabetes and was treated by oral antidiabetics. A physical examination revealed hyperpigmented macules arranged in a reticulate pattern, mainly on the chest, abdomen, lumbosacral area, and neck (Figs. 1 and 2). She had no acanthosis nigricans or other associated symptoms. The main diagnoses considered were pityriasis versicolor, confluent and reticulated papillomatosis of Gougerot–Carteaud, and prurigo pigmentosa. A histological examination revealed a discreetly atrophic epidermis surmounted by compact orthokeratotic hyperkeratosis and slight basal pigmentation. The dermis was the site of perivascular mononuclear infiltrates associated with a small number of melanophages. Periodic acid–Schiff staining was negative. This was consistent with the diagnosis of prurigo pigmentosa.