Pure neuritic leprosy in patients from a high endemic region of Colombia.

Agua de Dios was a leprosarium for leprosy patients' obligatory isolation (1872-1961). Its leprosy incidence is the highest in Colombia (1.5-7/10000). Relapses are common. Government grant of US$ 200 per month subsidy is available to patients with disabilities. Spontaneous consultation with neural symptoms is frequent and simulation to get the subsidy has to be considered. We studied 36 subjects (2007-2009), with ages from 29-78, 19 of them men, with neural symptoms of 6 months to 20 years evolution. All had clinical examination, bacteriological examination, skin and nerve biopsies, electromyography (EMG), PCR for M. leprae, IgM anti-PGL1, and lepromin A. All but two are household contacts of leprosy patients. Symptoms were hypoesthesia of the hands and feet, and difficulty using hands with loss of muscular strength. None had skin lesions. Three had thickening of ulnar nerve. Lepromin was positive in all; bacteriology and biopsies were negative in all. The speed and amplitude of neural conduction were altered in 34 patients; two women had normal EMG and were considered to be feigning the disease; 21 were diagnosed as PNL by clinical, epidemiological and EMG findings; five of them had a positive PCR and one, high titers for IgM anti PGL1. Nine other subjects had diabetes and six carpal tunnel syndrome (CTS). Slow progression of disease, the lack of neural enlargement and the neural biopsies without inflammation suggest that most of these patients could have spontaneously cured PNL, as happens with other cases of paucibacillary leprosy. Diabetes and CTS are important differential diagnoses of PNL. Patients were treated with MDT and received the state subsidy.