Blood flow velocity in cutaneous lesions of leprosy

The velocity of blood flow in the cutaneous lesions of leprosy was measured by the noninvasive technique of laser-Doppler velocimetry in nine male patients, all under treatment with World Health Organization multidrug regimens. In three patients with stable borderline tuberculoid (BT) lesions, the blood-flow velocity was slightly faster over the lesion than that in adjacent uninvolved skin. There was no substantial difference between different sites at the center and edge of individual lesions in each patient, but there was some variation between subjects. In one other BT patient with a reversal reaction, blood-flow velocity was 20-fold greater than in adjacent uninvolved skin. In four patients with stable borderline lepromatous/lepromatous (BL/LL) disease, the blood-flow velocity was 3 to 9 times faster over the plaques than in adjacent skin. There was relatively little difference between measurements over comparable points at the edge and center of individual plaques, or between plaques in the same patient, but there were considerable differences between patients. A fifth BL patient in reversal reaction showed generally similar results to those found in the stable BL/LL patients. Histometric study of the biopsies taken immediately after blood-flow measurement from two different plaques on each of four BL patients showed a clear relationship between the granuloma fraction measured by planimetry and the blood-flow velocity. This finding suggests that laser-Doppler velocimetry might prove to be a useful, clinically acceptable, noninvasive technique for monitoring the severity of hyperemia as an early indication of reversal reaction during chemotherapy trials in leprosy patients.