Friday, August 7, 2015

Cutaneous Tuberculosis

  • Cutaneous tuberculosis (TB) is essentially an invasion of the skin by Mycobacterium tuberculosis, the same bacteria that cause TB of the lungs (pulmonary TB).
  • Cutaneous TB is a relatively uncommon form of extrapulmonary TB (TB infection of other organs and tissues). 
Types of cutaneous TB:

  • Several different types of cutaneous TB exist.
  • Direct infection of the skin or mucous membranes from an outside source of mycobacteria results in an initial lesion called the tuberculous chancre.
  • The chancres are firm shallow ulcers with a granular base.
  • They appear about 2-4 weeks after mycobacteria enter through broken skin.
  • The immune response of the patient and the virulence of the mycobacteria determine the type and severity of cutaneous TB.





Investigation:
  • The diagnosis is usually made or confirmed by characteristic histopathological features on skin biopsy.
  • Typical tubercles are caseating epithelioid granulomas that contain acid-fast bacilli.
  • These are detected by tissue staining, culture and polymerase chain reaction (PCR).



Treatment for Cutaneous Tuberculosis:

  1. Patients with pulmonary or extrapulmonary TB disease need to be treated with antitubercular drugs.
  2. This usually involves a combination of antibiotics (isoniazid, rifampicin, pyrazinamide and ethambutol) given over a period of several months and sometimes years.
  3. Occasionally surgical excision of localized cutaneous TB is recommended.
  4. According to a journal published in 2009 on Dermatology, Cutaneous Tuberculosis (CTB) treatment is the same as that for systemic TB and consists of long, multidrug therapy.

Recommendations:
  • Although the incidence of CTB is rare, it should be considered in patients presenting with atypical skin lesions suggestive of an underlying infectious etiology.
  • It is imperative that physicians have a high index of suspicion in order to quickly and effectively diagnose and treat these substantially morbid skin conditions.
  • Prompt consideration leads to a swift diagnosis and proper treatment resulting in high patient satisfaction

References:
http://dermnetnz.org/pathology/tuberculosis-path.html
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2923933/
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4230662/


No comments:

Post a Comment

Note: Only a member of this blog may post a comment.