MARY SSTONEMDSOONBAHRAMIMDCARRIE ANN RCUSACKMDSENAIT WDYSONMDMOLLY AHINSHAWMDVINCENTLIUMD
The skin biopsy specimen demonstrated hyperkeratosis, papillomatosis, and acanthosis. The basal layer of the epidermis showed increased pigmentation, and the dermis displayed a mild superficial perivascular lymphohistiocytic infiltrate and a few scattered dermal melanophages.
Idiopathic eruptive macular pigmentation was first reported by Degos et al1 in 1978. Sanz de Galdeano et al2 offered the following diagnostic criteria for IEMP: (1) eruption of brownish nonconfluent asymptomatic macules involving the trunk, neck, and proximal aspect of the extremities in children or adolescents; (2) absence of preceding inflammatory lesions; (3) no previous drug exposure; (4) histologic examination showing basal cell layer hyperpigmentation of the epidermis and prominent dermal melanophages without visible basal layer damage or lichenoid inflammatory infiltrate; and (5) normal mast cell count.
Multiple Brown Patches on the Trunk—Diagnosis. Arch Dermatol. 2010;146(11):1301-1306. doi:10.1001/archdermatol.2010.320-b