BackgroundLeprosy is associated with different dermatologic and neurologic manifestations within a wide clinical spectrum, causing a great diagnostic challenge. Therefore, we aimed to examine associations between common presenting symptoms of leprosy and stage at diagnosis. Methodology/Principal findingsIn this cross-sectional study, we analyzed population-level data from the Leprosy Management Information System (LEPMIS) in Yunnan, China, from 2010-2020 and enrolled patients with newly detected leprosy. The data of 2125 newly detected leprosy patients, with 5000 symptoms, were analyzed. Numbness (828/5000, 16.56%), erythema (802/5000, 16.04%), Painless nor pruritic skin lesions (651/5000, 13.02%), eyebrow hair loss (467/5000, 9.34%), and tubercles (442/5000, 8.84%) were common symptoms of leprosy. The symptoms related to skin (1935/2533, 76.39%) and leprosy reaction (279/297, 93.94%) were mainly existed in MB group. While the symptoms related to disability (263/316, 83.49%), clinical feature (38/56, 69.09%), and facial features (19/23, 82.61%) were predominantly presented in delayed diagnostic group. Despite low proportions, formic sensation (99/5000, 1.98%), pain (92/5000, 1.84%), pruritus (56/5000, 1.12%), finger contracture (109/5000, 2.18%), muscle atrophy (71/5000, 1.42%), and motor dysfunction (18/5000, 0.36%) were reported during the diagnosis of leprosy. The proportions of skin, skin and nerve, and nerve symptoms as initial symptoms were 33.25%, 44.95%, and 21.80% and as only symptoms were 28.66%, 57.81%, and 13.91%, respectively. In those with physical disability, nerve symptoms were the most frequent symptoms (57.65% and 65.36% for the initial and only symptoms, respectively) compared with skin and skin and nerve symptoms. In the delayed diagnosis group, nerve symptoms were the most frequent symptoms (15.73% and 17.25%) and were associated with the longest diagnostic intervals (mean +/- SD: 38.88 +/- 46.02 and 40.35 +/- 49.36 months for initial and only symptoms, respectively) when compared with skin and skin and nerve symptoms. ConclusionsUnderstanding the nature of presenting symptoms and developing symptom awareness campaigns would improve the level of leprosy awareness in the community. As nerve symptoms were related to a higher proportion of physical disability and longer diagnosis interval, we should increase awareness about nerve symptoms. Individuals with nerve symptoms should be considered the target group. Neurology outpatient visits may provide potential screening opportunities, and holding focused training for specialized neurology medical staff would enhance the capacity of the health system to recognize leprosy early. Author summaryEarly diagnosis is key in leprosy control; however, the diagnosis of leprosy is still challenging. In this study, we reviewed the common and rare symptoms of leprosy. Numbness, erythema, painless nor pruritic skin lesions, eyebrow hair loss, and tubercles were common symptoms of leprosy. Despite low proportions, formic sensation, pain, pruritus, finger contracture, muscle atrophy, and motor dysfunction were also reported by leprosy patients. As initial symptoms at symptom onset and only symptoms at diagnosis, nerve symptoms were associated with a greater degree of physical disability and a longer diagnosis interval than skin and skin and nerve symptoms. Understanding the presenting symptoms in detail would improve the level of leprosy awareness in the community. Increasing awareness of nerve symptoms, focusing on individuals with nerve symptoms at neurology outpatient visits, and holding focused training for medical staff specializing in neurology would enhance the capacity of the health system to recognize leprosy early.