Urticaria pigmentosa treated with oral disodium cromoglycate.

4 patients with urticaria pigmentosa were treated with oral disodium cromoglycate (DSCG) for 2 months. During the treatment urine excretion of the main histamine metabolite, 1,4-methylimidazoleacetic acid (MIAA), was determined, and sequential skin biopsies were examined. DSCG was found to have beneficial effect on pruritus and whealing in 3 patients. The one treatment failure was in a patient without pruritus. The skin lesions remained unchanged. DSCG treatment had no effect on MIAA excretion or on the number of mast cells found in the skin biopsies.