Course of Urticaria Pigmentosa in Children

The benign nature of urticaria pigmentosa as seen in children is well known.1,2"Clear by puberty" has been the watchword of reassurance passed down through 4 generations of dermatologists,3except for the rare dissenter.4Even the recognition that these peculiar urticating spots may on occasion be an indication of widespread underlying mast-cell disease has not significantly changed the prognosis for the ordinary case. But just how accurate is this prediction? Are there any signs early in the disease which may provide clues in distinguishing which case will be short-lived and which more prolonged? The following study was undertaken to answer these questions. Method of Study Thirty-seven cases of urticaria pigmentosa (cutaneous mast-cell disease) with onset in the first decade of life were selected from the more than 150 patients with this diagnosis seen at the Mayo Clinic from 1917 through 1959. Atypical cases, in which histologic confirmation