Background: Leprosy neuropathy is the most common peripheral neuropathy of infectious etiology worldwide; it is characterized as asymmetric and focal multiple mononeuropathy. Semmes-Weinstein monofilament (SWM) test is a simple method to assess sensory nerve function. Methods and findings: In this prospective cohort study, a dermatologist carried out hands and feet tactile sensation test with SWM in 107 multibacillary leprosy patients at diagnosis and in 76 patients at the end of treatment from 2016 to 2019. At diagnosis, 81/107 (75.7%) patients had some degree of functional disability, and 46 (43%) of them had altered SWM-test in the hands and 94 (87.9%) of them in the feet. After one year of multibacillary multidrug therapy, the disability decreasing to 44/76 patients (57.9%) and decreasing of the percentual of patients with altered SWM-test to 18% for the hands, and to 28.7% for the feet. At the end of treatment, the number of SMW-test points presented improvement in the hands of 22 (28.9%) patients, and in the feet of 47 (61.8%). In the hands, by SWM-test, only the radial nerve point demonstrated a significant asymmetry, while in the feet, the difference between the sum of altered SWM-test points showed significant asymmetry between both sides, highlighting the tibial nerve for the establishment of asymmetric leprosy neuropathy. In Spearman’s correlation analysis, a positive correlation with statistical significance was observed between the number of hands and feet SWM altered points at diagnosis and the degree of disability at diagnosis (0.69) and at the end of the treatment (0.80). Conclusion: The patterns of hands and feet tactile sensation at diagnosis and their consequent modifications with the anti-leprosy drugs define the bacterial etiology of neuropathy, an important tool for the clinical diagnosis and follow up of the disease, highlighting the tibial nerve findings, the most affected nerve among leprosy patients by SWM-test, with significant asymmetry and focality impairments.

In Brazil, pentavalent antimonials (Sb⁺⁵) are the first-line drugs for Lb infection treatment. Despite high efficacy, the numerous side effects, such as cardiac, renal and hepatic toxicity, induced by these drugs consequently restricts use to certain groups of patients.² In addition, recent studies have demonstrated increasing resistance to these antimonials in several Latin American countries, as well as in India.^6,7,8 In light of this scenario, several studies have investigated alternative treatment strategies, such as combined therapy involving Sb⁺⁵ and immunomodulators, such as pentoxifylline, an inhibitor of TNF production, which seemed to accelerate cure in patients.^1,9

Key words: leprosy; antibodies; Mce1A protein; diagnosis; immunoglobulin

Leprosy can be considered a dissimulated disease, mainly when presented as atypical cases leading to mistaken diagnosis at the emergency setting. Herein we report six patients referred to the emergence room with hypotheses of acute myocardial infarction and arterial and venous thrombosis, although with chronic neurological symptoms; the seventh patient was referred with a wrong suspicion of infected skin ulcer. Positive findings included hypo-anesthetic skin lesions and thickened nerves; 100% were negative for IgM anti-phenolic glycolipid-I, while 71.4%, 100% and 42.8% were positive for IgA, IgM and IgG Mce1A. RLEP-PCR was positive in all patients. Ultrasound of peripheral nerves showed asymmetric and focal multiple mononeuropathy for all patients. Unfortunately, in many patients leprosy is often misdiagnosed as other medical conditions for long periods thus delaying initiation of specific treatment. This paper is intended to increase physicians' awareness to recognize leprosy cases presented as both classical and unusual forms, including in emergency department.

Leprosy, a neglected tropical disease, is reported in over 120 countries, with upwards of 200,000 new cases annually. This Cross-Sectional Cohort Study aimed to delineate the epidemiological profile of leprosy in a low-endemic area in southern Brazil, both before and after implementing an active search strategy. The study examined two surveillance periods in Caçador, Santa Catarina, Brazil. The active search strategy was carried out through the application of the LSQ by the community health workers as a screening and detection tool for new cases of leprosy and this was compared with passive case detection. The first spanned from 2014 to 2020, and the second from January 2021 to August 2023. 48 leprosy cases were reported throughout the study, 83.3 % of which were diagnosed as multibacillary. The first period had an average detection rate of 0.38 cases per 10,000 inhabitants, increasing to 1.19 cases per 10,000 inhabitants in the second period. Notably, there was a substantial shift in the degree of physical disability (GD), with more Grade 0 and Grade 1 disabilities observed post-active search. The study underscores the efficacy of active search strategies in early diagnosis, highlighting a 300 % increase in the annual average of diagnosed cases. This large number of detected cases demonstrates the high sensitivity of the LSQ. This approach significantly aids in uncovering hidden cases of leprosy, enhancing disease management and control in low-endemic areas indicating that the Ministry of Health should intensify leprosy control activities in these regions.