Extrapulmonary tuberculosis

Epidemiologic risk factors include birth in high TB-prevalent countries, exposure at place of residence/work in an institutional setting, and homelessness.

Diagnosis may be delayed as a result of nonspecific clinical manifestations that progress slowly and the low sensitivity of acid-fast bacilli (AFB) smear on extrapulmonary specimens.

Microbiologic proof is the key to diagnosis and treatment, and tissue biopsy is frequently required. Other supportive findings are granulomas and positive AFB stain on pathology, and chest x-ray findings.

Initial therapy is a 4-drug regimen of isoniazid, rifampin, pyrazinamide, and ethambutol; treatment lasts for at least 6 months.

Tuberculosis (TB) is caused by Mycobacterium tuberculosis. In many cases, M tuberculosis infection becomes latent before progression to active TB disease. Patients who are infected but who have no clinical, bacteriologic, or radiographic evidence of active TB are said to have latent TB infection. When there is progression from latent infection to active disease, it most commonly involves the lungs and is communicable in this form, but may affect almost any organ system including the lymph nodes, CNS, bones/joints, genitourinary tract, abdomen (intra-abdominal organs, peritoneum), and pericardium. When TB occurs in organ systems other than the lungs, it is referred to as extrapulmonary TB (EPTB).