Urticaria-pigmentosa-like lesions in acute lymphoblastic leukaemia (2 cases).

Two males aged 12 and 38 years presented with widespread severely pruritic blackish spots for 15 days. Widespread slate-grey patches and erythematous hyperpigmented plaques were observed with a positive Darier's sign. There were associated neck swellings, abdominal pain, anorexia, weight loss and bleeding gums in both. Peripheral blood and bone marrow showed blast cells, anaemia and thrombocytopenia. Cell surface markers confirmed the presence of acute lymphoblastic leukaemia. Skin biopsy showed an infiltrate of lymphoblasts as well as mast cells. Partial response was noted with cytotoxic therapy in 1 patient. Thus lesions mimicking urticaria pigmentosa may be the presenting sign of acute lymphoblastic leukaemia.