A seven-year retrospective analysis of patch test data in a cohort of patients with contact dermatitis in Sri Lanka.

BACKGROUND: Patch testing with a baseline series is a common tool employed when the sensitizing agent in contact dermatitis is unclear. However, for Asian countries, there are no locally validated baseline series to utilize in screening. METHODS: We completed a retrospective analysis of all patients that had undergone patch testing with the European Baseline series, Shoe Series or Comprehensive International Baseline series, over 7 years from 2012 to 2018 in a tertiary care reference dermatology clinic in Sri Lanka to evaluate the suitability of these investigations to identify causes for contact dermatitis in the local study population. RESULTS: Out of 438 patients tested, 239 (54.8%) reacted to at least one substance in the series. The Shoe Series was significantly more likely to yield a positive result than the European Baseline Series (70.2% vs 46.9%, p < 0.05). The top three sensitizers identified by all series were nickel sulfate (16%, 70/438), p-phenylenediamine (12.3%, 54/438) and 2-mercaptobenzothiazole or mercapto mix (10.5%, 46/438). CONCLUSION: Shoe series has a comparatively high yield in the local population compared to European Baseline series. Since little less than half of the study population did not have any reactivity to any of the allergens tested it is important to develop or modify and validate a locally relevant, more suitable baseline series which is based on the Shoe Series in Sri Lanka. This is further evidence for the continuously changing nature of allergens in the environment and the need to modify existing patch testing standards accordingly.

Coexistence of mycobacterial infections - Mycobacterium tuberculosis and Mycobacterium leprae - in Sri Lanka: a case series.

BACKGROUND: Leprosy is one of the oldest mycobacterial infections and tuberculosis is the most common mycobacterial infection with a higher degree of infectivity than leprosy. Although both diseases are prevalent in clusters in developing countries, simultaneous occurrence of them in an individual is a rare entity, even in an endemic setting. CASE PRESENTATION: We describe six cases of tuberculosis and leprosy coinfection: a 57-year-old Sinhalese woman, a 47-year-old Tamil woman, a 72-year-old Tamil man, a 59-year-old Sinhalese man, a 54-year-old Sinhalese man, and a 50-year-old Sinhalese man. In this case series, five patients had lepromatous leprosy and the majority of patients were men. Three patients were detected to have tuberculosis at the outset of treatment of leprosy, while two developed tuberculosis later and one had extrapulmonary tuberculosis 5 years before the diagnosis of leprosy. The latter developed pulmonary tuberculosis as a reactivation while on treatment for leprosy. A majority of our patients with pulmonary tuberculosis had positive Mantoux test, high erythrocyte sedimentation rate, radiological evidence, and acid-fast bacilli in sputum. Human immunodeficiency virus and diabetes were detected in one patient. One patient had rifampicin-resistant tuberculosis, while she was on monthly rifampicin therapy for leprosy. CONCLUSION: An immunocompromised status, such as human immunodeficiency virus infection, diabetes, and immunosuppressive drugs, are risk factors for tuberculosis infection. The use of steroids in the treatment of leprosy may increase the susceptibility to develop tuberculosis. Development of rifampicin resistance secondary to monthly rifampicin in leprosy is a major concern in treating patients coinfected with tuberculosis. Despite the paucity of reports of coinfection, it is advisable to screen for tuberculosis in patients with leprosy, especially if there are respiratory or constitutional symptoms, high erythrocyte sedimentation rate, and abnormal chest X-ray. The fact is that positive Mantoux and QuantiFERON Gold tests and presence of acid-fast bacilli in sputum are misleading, chest X-ray evidence of active tuberculosis and positive tuberculosis cultures are important diagnostic clues for active tuberculosis infection in a patient with leprosy. This is important to avoid monthly rifampicin in patients with suspected coinfections, which may lead to development of drug resistance to tuberculosis treatment. Whether prolonged steroid therapy in leprosy is a risk factor for development of tuberculosis is still controversial.