Crusted (Norwegian) scabies in a patient with smoldering adult T-cell leukemia

Crusted (Norwegian) scabies is described in a patient with smoldering adult T-cell leukemia (ATL). The patient is an 84-year-old Japanese woman who presented with widespread scaling over the trunk and limbs and crusted lesions on the scalp and ears. Microscopical examination of scrapings from the scalp and ears showed extraordinarily large numbers of scabies mites. The white blood cell count was 5.1 x 10(9)/L with 6% abnormal lymphocytes with mature nuclei that showed convolution and lobulation. Anti-HTLV-I antibodies were positive. Southern blot analysis revealed that the cellular DNA extracted from this patient's peripheral blood cells, digested with Pst I, showed the same pattern of provirus genome as the DNA from ATL patients. A diagnosis of crusted scabies with smoldering ATL was made. It is possible that crusted scabies could be an opportunistic infection and a pre-diagnostic sign of ATL.