An Unusual Case of Incontinentia Pigmenti Presenting with Pa

10-day-old Caucasian female presented with her family to the emergency department for constipation. Dermatology was subsequently consulted for 7-day history of worsening rash. The mother had a normal pregnancy with prenatal care and a full term spontaneous vaginal delivery without complication. The patient was discharged from the hospital at Day 2 of life. Patient’s mother reports rash started as a few red bumps on her legs that spread to her trunk, upper extremities, and scalp. The rash did not seem to be symptomatic.

Physical exam was significant for firm pink papules and plaques over the trunk, arms, legs, and scalp along with scattered areas of fine desquamation on patient’s arms and abdomen. Patient had no palpable lymphadenopathy. We performed a 4MM punch biopsy on the patient’s right lateral thigh. Differential diagnosis at the time of biopsy was a depositional or fibrosing disorder versus subcutaneous fat necrosis of the newborn. Histopathologic examination demonstrated spongiosis with numerous eosinophils, and rare dyskeratotic cells within the epidermis consistent with Incontinentia Pigmenti....