Digital blood circulation in paucibacillary leprosy

Abstract

Digital vascular flow in paucibacillary leprosy was assessed photoplethysmography (PPG). In PPG, infra-red light emitting diode and an adjacent photosensor detect the blood flow in cutaneous capillaries, as represented graphically on a strip-chart. In 29 (6F, 23 M) untreated paucibacillary leprosy patients (7TT, 16 BT and 6 purely neural type) having ailment on limb/limbs, suffering for 5 months to 12 years, PPG recording were done by applying the device to the distal phalanges of all the digits of four limbs serially with Velcro-strap at an ambient temperature of 28 °C - 30 °C and humidity of 60-70 percent. Diminished digital vascular flow of the affected limb/limbs was seen in long-standing cases suffering for > 2 years irrespective of the type, site, morphology or phase (reactional) of the disease. This may be mostly due to specific vascular changes rather than reactional or functional changes. Specific vascular changes are terminal arteritis, vasculitis of vasa nervorum or truncular arteritis, i.e.. tuberculoid lesions of the major arteries. Two patients, suffering for 1.5 years, paradoxically showed increased digital blood flow which is probably due to reactive hyperaemia or paralytic vasodilatation as a result of autosympathectomy.