Adult Onset Urticaria Pigmentosa without Systemic Involvement: A Case Report

Cutaneous mastocytosis is a rare condition characterized by abnormal accumulation of mast cells in the skin. The most common clinical presentation, urticaria pigmentosa, manifests as itchy, brownish macules or plaques predominantly on the trunk and proximal extremities. In adults, it is generally associated with systemic involvement, making isolated cutaneous presentations highly unusual. We report a rare case of isolated urticaria pigmentosa in a 28 year-old adult male, presenting without systemic involvement confirmed through exhaustive investigations. Treatment with antihistamines and topical corticosteroids resulted in rapid clinical improvement. This case highlights the necessity for comprehensive evaluation to exclude systemic mastocytosis in adults.