Leprosy serology (ML Flow test) in borderline leprosy patients classified as paucibacillary by counting cutaneous lesions: an useful tool.

Leprosy remains an endemic disease in Brazil, with almost 40,000 new cases diagnosed each year. As it is difficult to perform laboratory procedures in the field, operational classification is determined by counting lesions, which can cause underdiagnosis of multibacillary cases and failures in treatment. To evaluate a new tool to diagnose MB cases, the ML Flow test, 21/77 (27.3%) patients with untreated borderline leprosy (6 BL and 15 BT) with 1 to 5 cutaneous lesions were evaluated according to the R&J Classification. The ML Flow test was positive in 14/21 (66.6%) patients; 7/21 (33.3%) cases, 5 BT and 2 BL, showed negative results. Classification of leprosy based only on the number of lesions can fail to diagnose MB leprosy. The ML Flow test is a useful tool to diagnose borderline leprosy in patients with 1 to 5 cutaneous lesions.