Cutaneous mastocytosis in Singapore

Mastocytosis is the collective name for a group of clinical syndromes whose signs and symptoms are due to the infiltration of various tissues by mast cells and to the release of chemical mediators by these cells. The skin is the most frequently affected organ. Skin manifestations include urticaria pigmentosa, mastocytoma, diffuse cutaneous mastocytosis and telangiectasia macularis eruptiva perstans. Seven cases of mastocytosis were seen over a 3-year period at the National Skin Centre from 1989 to 1992. All our patients were in the paediatric age group. There were four boys and three girls ranging in age from one year to five years. The mean age of onset of the disease was 2.3 months. Six patients presented with cutaneous signs and symptoms of urticaria pigmentosa and one patient had diffuse cutaneous mastocytosis. Itch was the most prominent symptom seen in all the patients. All the patients had a positive Darier's sign, pathognomonic for mastocytosis. None of the patients had a positive family history. Treatment was conservative and symptomatic, with the use of H1 antihistamines to control itching. A particularly important aspect of management is the avoidance of triggering factors. All our patients have remained well with only skin involvement. The prognosis for children with mast cell disease is good, with at least half of the children with urticaria pigmentosa experiencing reduction of symptoms and lesions by adolescence.