Prurigo pigmentosa

Case I A 28-year-old woman with skin type 2 was first seen in May 1997 with a 10-year history of a recurrent pruritic eruption in the intermammary are a. Her medical history was not significant regarding a systemic disease or a triggering factor that could have been related to her eruption. Results o f laboratory investigations, including peripheral brood cell counts, liver and renal function tests, blood glucose levels, and urinalysis, were within normal limits. Physical examination revealed erythematous papules and reti culated hyperpigmentation in the intermammary area. Histopathologic examina tion from an erythematous papule showed parakeratosis, mild acanthosis, spo ngiosis, dyskeratotic keratinocytes, and focal Vacuolar degeneration of bas al keratinocytes within the epidermis; and perivascular lymphocytic infiltr ate and pigment incontinence within the upper dermis (Fig. 1), Following an initial treatment with topical corticosteroid for 2 weeks with a partial r esponse, doxycycline was started in 200 mg daily doses for 3 weeks. The eru ption resolved leaving marked residual hyperpigmentation within 3 weeks. No recurrence has been observed over the past 6 months. Case 2 A 23-year-old woman with skin type 3 presented in June 1997 with a 2 -month history of a recurrent pruritic eruption on her chest. She denied an y provoking factor that could have been responsible for her eruption. Her e xamination revealed erythematous papules and reticulated hyperpigmentation localized to the inframammary area (Fig. 2). Skin biopsy showed focal parak eratosis, minimal acanthosis, spongiosis, and a lymphocytic infiltrate arou nd the blood Vessels of the upper dermis. The lesions resolved spontaneousl y leaving residual reticulated hyperpigmentation within 2 weeks. The follow ing course of her lesions is not known as she was lost to follow-up.