REPORT OF A CASE
A 6-year-old white girl was referred with multiple pruritic papules predominantly affecting the face and neck but also involving the arms and upper torso. These lesions (Fig 1) had been appearing in increasing number over the preceding 6 months. Each salmon-pink annular papule was 5 to 10 mm in diameter and usually asymptomatic. When stroked, they became pruritic, erythematous, and edematous (Fig 2). Over several months, these lesions faded and flattened, leaving a macule of wrinkled skin. When palpated, this skin would allow the finger to press with ease into the dermis, unlike the normal-appearing surrounding skin. An excisional biopsy was performed (Figs 3 through 5).What is your diagnosis?
Urticaria pigmentosa (UP) with secondary anetoderma.
A low-power photomicrograph stained with hematoxylin-eosin (Fig 3) showed a mild perivascular inflammatory cell infiltrate in the dermis. Many of these cells contained
Gebauer KA, Navaratnam TE, Holgate C. Pruritic Pigmented Papules Posing Permanent Problems. Arch Dermatol. 1992;128(1):110. doi:10.1001/archderm.1992.01680110121023