leprosy (Hansen's disease)
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Classification
- indeterminate
- frequently initial form
- resolves spontaneously or evolves into other forms
- lepromatous
- most contagious form
- mainly affects skin
- peripheral nerves may be affected
- other symptoms may be present
- tuberculoid
- affects skin & peripheral nerves
- generally few lesions
- borderline
- intermediate between lepromatous & tuberculoid forms
Etiology
caused by Mycobacterium leprae
Epidemiology
- endemic in tropical & subtropical regions (India, Brazil, Indonesia)
- rare in the U.S. (150-250 cases/year)
- only 18% of people born outside the U.S. but later diagnosed with leprosy had symptoms before entering the U.S.[5]
- incubation period often lasts 3-7 years[5]
- armidillos may be carriers in southwest US[4]
- ~100 cases/years reported in U.S. (CDC)
Pathology
- chronic granulomatous disease
- associated with depressed cellular immunity
- humoral immunity appears to be intact
- etiologic agent M leprae thrives particularly in peripheral Schwann cells & macrophages
- dystroglycan is a receptor for the entry of Mycobacterium leprae into peripheral nerve Schwann cells
Microscopic pathology
- perivascular & perineural pattern
- thrombosis of medium-sized arteries, with surrounding lymphohistiocytic infiltrate containing plasma cells & foamy macrophages
- acid-fast bacilli with invading vascular endothelial wall may be seen on tissue staining (Fite-Faraco)
* images (histopathology)[6]
Genetics
- susceptibility associated with locus on chromosome 10p13
- polymorphisms in 5' regulatory regions shared by PARK2 & PACRG genes also confer susceptibility (chromosome 6q25-27)
- genetic variations in TLR2 are associated with suceptibility to leprosy
- polymorphisms in lymphotoxin-alpha (LTA) accounts, in part, for susceptibility to leprosy linked to chromosome 6p21.3
Clinical manifestations
- incubation period often lasts 3-7 years[5]
- nasal discharge
- dysphagia
- hoarseness
- skin manifestations
- skin lesions are indurated & may be hypoesthetic or anesthetic
- skin nodules, macules & papules symmetrically distributed on forehead, cheeks, ears
- persistent ulcerations
- coalescent ulceronecrotic areas over the trunk, arms, & legs[6]
- painful, blistering skin lesions (case report)[6]
- case of scattered painless skin nodules on distal extremities
- hypoesthesia noted within lesions
- retiform purpura[6]
- loss of eyebrows, swelling of earlobes, absence of facial wrinkles, diffuse alopecia (case report)[6]
- generalized lymphadenopathy
- persistent neuropathy
- saddle nose deformity
* images (Lucio's phenomenon, diffuse lepromatous leprosy)[6]
Laboratory
- culture of organisms from blood & nasal secretions
- false positive VDRL
- anemia
- skin biopsy
Management
- rifampin, clofazimine & dapsone for 12 months
- rifampin, ofloxacin & minocycline as a single dose for paucibacillar leprosy
- systemic glucocorticoids & anticoagulation for diffuse lepromatous leprosy[6]
More general terms
Additional terms
- Mycobacterium leprae
- parkin coregulated gene protein; molecular chaperone/chaperonin-binding protein; PARK2 coregulated gene protein (PACRG, GLUP)
References
- ↑ Stedman's Medical Dictionary 26th ed, Williams & Wilkins, Baltimore, 1995
- ↑ DeGowin & DeGowin's Diagnostic Examination, 6th edition, RL DeGowin (ed), McGraw Hill, NY 1994, pg 905
- ↑ Ramose-e-Silva M & Rebello PF, Am J Dermatol 2:203, 2001
- ↑ 4.0 4.1 Truman RW et al. Probable zoonotic leprosy in the southern United States. N Engl J Med 2011 Apr 28; 364:1626. PMID: https://www.ncbi.nlm.nih.gov/pubmed/21524213
- ↑ 5.0 5.1 5.2 5.3 Nolen L et al Incidence of Hansen's Disease - United States, 1994-2011 MMWR. Weekly October 31, 2014 / 63(43);969-972 http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6343a1.htm
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 Tajalli M, Wambier CG Images in Clinical Medicine: Lucio's Phenomenon. N Engl J Med 2021; 384:1646. April 29 PMID: https://www.ncbi.nlm.nih.gov/pubmed/33913641 https://www.nejm.org/doi/full/10.1056/NEJMicm2025081
- ↑ Elkston CA, Elkston DM Bacterial Skin Infections: More Than Skin Deep. Medscape. July 19, 2021 https://reference.medscape.com/slideshow/infect-skin-6003449
- ↑ White C, Franco-Paredes C. Leprosy in the 21st century. Clin Microbiol Rev. 2015 Jan;28(1):80-94. PMID: https://www.ncbi.nlm.nih.gov/pubmed/25567223 PMCID: PMC4284303 Free PMC article. Review.
- ↑ Rodrigues LC, Lockwood DNj. Leprosy now: epidemiology, progress, challenges, and research gaps. Lancet Infect Dis. 2011 Jun;11(6):464-70. PMID: https://www.ncbi.nlm.nih.gov/pubmed/21616456 Review.
- ↑ Maymone MBC, Laughter M, Venkatesh S et l Leprosy: Clinical aspects and diagnostic techniques. J Am Acad Dermatol. 2020 Jul;83(1):1-14. PMID: https://www.ncbi.nlm.nih.gov/pubmed/32229279 Review.
- ↑ Alemu Belachew W, Naafs B. Position statement: LEPROSY: Diagnosis, treatment and follow-up. J Eur Acad Dermatol Venereol. 2019 Jul;33(7):1205-1213. PMID: https://www.ncbi.nlm.nih.gov/pubmed/30945360 Review.