URTICARIA PIGMENTOSA - A CLINICAL, HEMATOPATHOLOGIC, AND SEROLOGIC STUDY OF 30 ADULTS

Urticaria pigmentosa (UP) is the most common form of cutaneous mastocy tosis and may be associated with systemic involvement, most often of t he bone marrow. The incidence of systemic involvement is not yet well established, however. To address this question, we subjected a group o f 30 adults with histologically proved UP to a retrospective study tha t included history, physical examination, laboratory tests including c ytokine measurements, radiologic examinations, and bone marrow biopsie s. The most frequently associated clinical symptoms were recurrent flu sh episodes in 16 of 30 patients, alcohol intolerance in 13, pruritus in 10, and gastrointestinal problems in 11 (recurrent diarrhea, 8 pati ents; gastritis, 2 patients; and history of peptic ulcer, 1 patient). Of the 30 patients, 18 (60%) had mast cell infiltrates of the bone mar row (nodular type, 10 patients; diffuse interstitial type, 8 patients) . Bone marrow involvement was not correlated with massive cutaneous ma st cell infiltration, clinically or histologically, or with the incide nce of clinical symptoms and associated hematologic disorders. None of the patients had experienced progression of clinical symptoms, skin o r organ involvement, or development of hematologic malignant neoplasms since UP was first diagnosed (10 years on average). Urticaria pigment osa was found associated with mast cell infiltration of the bone marro w in 18 patients (60%). However, bone marrow involvement does not seem to predict adverse clinical course.