Urticaria pigmentosa

Urticaria pigmentosa (UP) is a rare disease under the disease category of mastocytosis where the skin is excessively infiltrated by mast cells. Nettleship and Tay made the original description of UP in 1863.(1) It can present as a solitary lesion, referred to as a mastocytoma, or in a diffuse form. Diffuse involvement manifests in one of five forms: telangiectasia macularis eruptiva perstans (TMEP), diffuse bullous, diffuse erythrodermic, diffuse doughy, or maculopapular (Table 1).(2) The maculopapular type is most common. This article is a review of the current literature on UP with an emphasis on evaluation and treatment.