Background: Leprosy or Hansen’s disease predominantly affects skin and peripheral nerves; therefore, can cause visible deformities from sensory and motor impairment. Early detection of sensory deficit has been of great benefit in a vigorous preventive role.

Objective: To compare the result of sensory evaluation in multibacillary leprosy (MB) patients using Semmes-Weinstein monofilament (SWM) and conventional monofilament technique used in Thailand and to observe the course of neuritis detected during the study period.

Material and Method: MB patients from Hansen’s clinic at the Department of Dermatology, Siriraj Hospital, and Leprosy clinic at Raj Pracha Samasai Institute were evaluated for sensory impairment using monofilament test by both SWM and conventional technique for two consecutive follow-up visits. The patients’ demographic data, clinical and laboratory findings, and course of disease were recorded.

Results: Seventy MB patients were enrolled. Two-third of the patients were male (71.4%) and a mean (SD) age was 43 (15.75) years with a range of 19 to 85-years-old. The results from SWM and conventional Thai technique were not statistically different for ulnar, median, and posterior tibial nerve distribution excluding heel area (p = 1.00). Twenty-eight (40%) patients who mentioned of numbness at either palms or soles had impaired sensation detected by SWM technique (p = 0.014).

Conclusion: Using SWM with less tested points can minimize the time spent on sensory evaluation in MB patients; hence, we encourage the application of the present SWM technique to shorten the time in each follow-up visit and to improve the follow-up practice for better services of leprosy patients in Thailand.

Keywords: Monofilament, Leprosy, Hansen’s disease, Sensory impairment