Atypical Presentation of Adult T-cell Leukaemia/Lymphoma due to HTLV-1: Prurigo Nodularis Lasting Twelve Years Followed by an Acute Micropapular Eruption.

Prurigo nodularis is a pruritic dermatosis of unknown origin. Human T-cell lymphotropic virus type I (HTLV- 1) causes adult T-cell leukaemia/lymphoma. HTLV-1 is not considered to be a cause of prurigo nodularis. A 52-year-old black man, from the French West Indies, who had had prurigo nodularis for 12 years, presented with a distinct micropapular eruption with the typical pathological picture of epidermotropic T-cell lymphoma. Based on HTLV-1-positive serology and monoclonal integration of HTLV-1 we diagnosed smouldering adult T-cell leukaemia/lymphoma. Re-examinination of previous skin biopsies revealed that the disease had been evolving for 12 years. Treatment with n-interferon, 3 × 106 units three times a week, associated with zidovudine, I g daily, resulted in complete remission within 4 months. When investigating a prurigo nodularis, we therefore recommend: (1) performing HTLV-1 serology if the patient comes' from an endemic area; (ii) if positive, performing CD25 staining and looking for a HTLV-1 clonal integration; and (iii) if positive, using a treatment targeting HTLV-1. [ABSTRACT FROM AUTHOR]