Leprosy overview

Jump to: navigation, search

Leprosy Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Leprosy from other Diseases

Epidemiology and Demographics

Risk Factors

Natural History, Complications and Prognosis

Diagnosis

Diagnostic Criteria

History and Symptoms

Physical Examination

Laboratory Findings

X Ray

Other Imaging Findings

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Secondary Prevention

Tertiary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Leprosy overview On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Leprosy overview

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Leprosy overview

CDC on Leprosy overview

Leprosy overview in the news

Blogs on Leprosy overview

Directions to Hospitals Treating Leprosy

Risk calculators and risk factors for Leprosy overview

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: João André Alves Silva, M.D. [2]

Overview

Leprosy is a chronic infectious disease caused by the bacterium Mycobacterium leprae.[1] Leprosy is primarily a granulomatous disease of the peripheral nerves and mucosa of the upper respiratory tract; skin lesions are the primary external symptom. Left untreated, leprosy can be progressive, causing permanent damage to the skin, nerves, limbs, and eyes.

Historical Perspective

Mycobacterium leprae, the causative agent of leprosy, was discovered by G. H. Armauer Hansen in Norway in 1873, making it the first bacterium to be identified as causing disease in man.[2][3] Historically, individuals with leprosy have been known as lepers, however, this term is falling into disuse due the pejorative connotation of the term.

Classification

The Ridley Jopling classification and the WHO classification are the two most widely used systems to classify Leprosy. These classification systems are based on clinical, microbiologic and histopathological features, and are used to determine the patient's prognosis and the treatment regimen.[4][5][6]

Pathophysiology

The clinical manifestations of leprosy largely reflect the immune response of the host towards the infection. Once the bacterial cells penetrate and multiply within the hosts skin and peripheral nerve cells, the immune system mounts a response toward the infected cells, which results in clinical symptoms. Several single-nucleotide polymorphisms such as TNF-α, IL-10, IFN-γ, TLR 1 have been associated with a greater susceptibility to leprosy as have other genetic markers.

Causes

Mycobacterium leprae is a gram-positive obligate intracellular, acid-fast bacillus, responsible for the development of leprosy, or Hansen's disease. This organism has a very slow growth and has a predilection to affect colder parts of the body, such as the skin, superficial nerves and upper respiratory mucous membranes. Although a route of transmission has not been absolutely defined yet, studies are pointing to a colonization of the dermis and respiratory mucosa of the infected patients. It is an uncommon bacteria, since it has only been noticed to infect and grow in some species of primates and in the nine-banded armadillo.[6]

Differential Diagnosis

Leprosy must be differentiated from other diseases that cause skin lesions, nodules, plaques paresthesias and nerve pain, such as autoimmune diseases, SLE, parasitic infections, vitiligo or cutaneous tuberculosis.

Epidemiology and Demographics

Current prevalence rate of leprosy per 100,000 is 3.7. The disease is more prevalent in endemic areas, which represent a potential source of spread of the disease to the rest of the world.

Risk Factors

Risk factors for contracting leprosy include close contact with an untreated, active multibacillary disease patient with the subtype of lepromatous leprosy, living in an endemic region (Angola, Brazil, Central African Republic, Democratic Republic of Congo, Federated States of Micronesia, India, Kiribati, Madagascar, Mozambique, Nepal, Republic of Marshall Islands, United Republic of Tanzania), age between 5 and 15 as well as over 30, Armadillo contact, tattoos, and genetic variants of the NOD2-mediated signaling pathway.

Natural History, Complications and Prognosis

Leprosy may lead to severe complications if not diagnosed and treated early, which will affect the prognosis.

Diagnosis

Diagnostic Criteria

The diagnosis of leprosy requires at least 1 of 3 criteria to be present: 1) loss of sensation of a hipopigmented skin patch, 2) a thickened peripheral nerve concomitantly with weakness or loss of sensation of the area, and/or 3) confirmation of mycobacterium leprae in a skin smear.

History and Symptoms

Common symptoms of leprosy include hypopigmented, anesthetic, red skin lesions, that are hard to heal, nodular growths on the skin, muscle weakness and paresthesia of the extremities and eye problems. If left untreated blindness and paralysis may occur.

Physical Examination

Although the findings on physical examination may vary depending upon the subytpe of leprosy, common findings include hypopigmented skin lesions, thickened dermis, and loss of sensation.

Laboratory Findings

There are no laboratory tests that diagnose leprosy.

X Ray

Osteoporosis is a common finding in leprosy patients which along with the loss of sensation may lead to fractures.

Other Imaging Findings

There are no other imaging studies that diagnose leprosy.

Other Diagnostic Studies

Biopsy of skin lesions and skin smear tests are important for the diagnosis of leprosy in patients whose clinical examination is suspicious of the disease.

Treatment

Medical Therapy

The medical treatment of leprosy is made with a multiple drug regimen, for 6 to 12 months. This drug regimen may include 2 or 3 drugs: rifampicin, dapsone and clofazimine, or rifampicin and dapsone, depending on the class of the disease.

Surgery

Surgery is not indicated in the treatment of leprosy, yet it may treat or decrease the impact of some of the complications that may arise from the disease.

Primary prevention

Primary prevention of leprosy includes immunoprophylaxis, chemoprophylaxis and education of the populations to prevent infection by the Mycobacterium leprae.

Secondary Prevention

There is no secondary prevention of leprosy available because it is not possible to know if contact with leprosy will lead to the development of the disease, until first symptoms appear.

Tertiary prevention

After treatment has been initiated, other measures to minimize further damage to the patient include: education of the individual and family members to monitor and treat skin ulcers and other lesions, primary care facilities to provide help to the populations and to direct patients to a specialist, whenever necessary.[7]

Cost-effectiveness of Therapy

After the results of the campaign of the WHO to eradicate leprosy, the treatment of this disease may be considered cost-effective.

Future or Investigational Therapies

Ongoing research focuses on the the mechanism of leprosy transmission as well as the identification of patients at high risk of infection in order to improve disease prevention and to treat infected individuals earlier. [7] Identification of alternatives to existing drugs, such as rifampicin is also critical in so far as these agents may be contraindicated either because of toxicity or resistance. [7]

References

  1. Sasaki S, Takeshita F, Okuda K, Ishii N (2001). "Mycobacterium leprae and leprosy: a compendium". Microbiol Immunol. 45 (11): 729–36. PMID 11791665.
  2. Hansen GHA (1874). "Undersøgelser Angående Spedalskhedens Årsager (Investigations concerning the etiology of leprosy)". Norsk Mag. Laegervidenskaben (in Norwegian). 4: pp. 1–88.
  3. Irgens L (2002). "The discovery of the leprosy bacillus". Tidsskr Nor Laegeforen. 122 (7): 708–9. PMID 11998735.
  4. Walker, Stephen L.; Lockwood, Dina N.J. (2007). "Leprosy". Clinics in Dermatology. 25 (2): 165–172. doi:10.1016/j.clindermatol.2006.05.012. ISSN 0738-081X.
  5. Eichelmann, K.; González González, S.E.; Salas-Alanis, J.C.; Ocampo-Candiani, J. (2013). "Leprosy. An Update: Definition, Pathogenesis, Classification, Diagnosis, and Treatment". Actas Dermo-Sifiliográficas (English Edition). 104 (7): 554–563. doi:10.1016/j.adengl.2012.03.028. ISSN 1578-2190.
  6. 6.0 6.1 Bhat, Ramesh Marne; Prakash, Chaitra (2012). "Leprosy: An Overview of Pathophysiology". Interdisciplinary Perspectives on Infectious Diseases. 2012: 1–6. doi:10.1155/2012/181089. ISSN 1687-708X.
  7. 7.0 7.1 7.2 "Enhanced global strategy for further reducing the disease burden due to leprosy (2011-2015)" (PDF).

Linked-in.jpg