Solitary mastocytoma improved by intralesional injections of steroid.

Solitary mastocytoma is an uncommon disease characterized by monotonous infiltrations of mast cells that extend from papillary dermis to subcutaneous fat. They usually resolve by adulthood, and there is no satisfactory treatment other than waiting. A two-month-old Korean male infant with deep solitary mastocytoma was treated intralesionally with triamcinolone acetonide. His mastocytoma in medial malleolus was very distressing because it was very sensitive to friction, and he was just reaching the crawling stage. After three injections, his skin lesion flattened with marked decrease of erythema and subjective symptoms. His skin lesion has continued to have a good clinical response for 9 months after the last treatment.