A traditional much feared disfiguring chronic bacterial infection of the skin and peripheral nerves caused by Mycobacterium leprae.
Commonly referred to as Hansen's disease.
Younger adult males most at risk. Known in India by 600 BC. Introduced to Europe by 1400's. Most of the 200,000 odd registered cases worldwide are in Southeast Asia. Since effective treatment in 1982, it has a WHO strategic plan for the leprosy elimination which is proceeding at 4% per annum. As of 2009 most activity is in Angola, Brazil, Central African Republic, Democratic Republic of Congo, India, Madagascar, Mozambique, Nepal and Tanzania.
Mycobacterium leprae. There is evidence that the NOD2-mediated signalling pathway which regulates immune response can be an important host factor in determining susceptibility and also response. It shares this with Crohn's disease.
Spectrum of disease from asymptomatic (most common) to tuberculoid and lepromatous. Rarely associated with [[glomerulonephritis, vasculitis, nerve palsy and granulomata anywhere (usually cooler areas body). For example, eyes can have lagophthalmos, corneal hypoaesthesia and iridocyclitis. Common qualifying terms are multibacillary (type 2 helper T (Th2) cell response active), paucibacillary (type 1 helper T (Th1) cells active) and borderline.
The characteristic skin lesions in association with thickened nerves are diagnostic.
Large well defined macular hypopigmented/erythematous anaesthetic lesions with usually raised margins or occasionally scaly patches
Widespread erythematous macules, papules or nodules.
- WHO recommended
- Small non‐necrotic granulomas
- Acid and alcohol fast bacilli
Tuberculin skin tests
A tuberculin skin test (TST) is performed by introducing tuberculin, a protein derived from mycobacteria, into the skin. Somebody with prior immunity to mycobacteria will produce a response to the test. A vigorous response may indicate current infection with a mycobacterium, most likely (in the UK) MTB.
- Early detection of the disease then treatment as human human spread only
- BCG vaccine. The disease can be prevented by vaccination with BCG vaccine (which prevents leprosy more effectively than it does tuberculosis).
- WHO multidrug treatment. For adults:
- Multibacillary (MD) leprosy for 12 months
- Paucibacillary (PB) leprosy for 6 months
- Single Skin Lesion Paucibacillary leprosy single dose regime
- Corticosteroids of leprous reactions and "silent neuropathies"
- Comprehensive care for prevention of disabilities and rehabilitation
- ↑ Zhang FR, Huang W, Chen SM, Sun LD, Liu H, Li Y, Cui Y, Yan XX, Yang HT, Yang RD, Chu TS, Zhang C, Zhang L, Han JW, Yu GQ, Quan C, Yu YX, Zhang Z, Shi BQ, Zhang LH, Cheng H, Wang CY, Lin Y, Zheng HF, Fu XA, Zuo XB, Wang Q, Long H, Sun YP, Cheng YL, Tian HQ, Zhou FS, Liu HX, Lu WS, He SM, Du WL, Shen M, Jin QY, Wang Y, Low HQ, Erwin T, Yang NH, Li JY, Zhao X, Jiao YL, Mao LG, Yin G, Jiang ZX, Wang XD, Yu JP, Hu ZH, Gong CH, Liu YQ, Liu RY, Wang DM, Wei D, Liu JX, Cao WK, Cao HZ, Li YP, Yan WG, Wei SY, Wang KJ, Hibberd ML, Yang S, Zhang XJ, Liu JJ. Genomewide association study of leprosy. The New England journal of medicine. 2009 Dec 31; 361(27):2609-18.(Link to article – subscription may be required.)