Extra-pulmonary Tuberculosis (EPTB): Causes, Symptoms and Diagnosis

Introduction

Extra-pulmonary tuberculosis refers to tuberculosis affecting organs and tissues outside the lungs. It is caused by members of the Mycobacterium tuberculosis complex and may occur when infection involves sites such as lymph nodes, bones, joints, the brain, kidneys, or other organs.

Tuberculosis can be difficult to diagnose when it occurs outside the lungs because symptoms vary according to the affected organ.

Common forms

  • Lymph-node TB: Often presents with enlarged lymph nodes.

  • Pleural TB: Affects the pleura surrounding the lungs.

  • TB meningitis: Involves the membranes covering the brain and spinal cord.

  • Bone and joint TB: May affect the spine or other skeletal structures.

  • Abdominal TB: Can involve the intestines, peritoneum, or abdominal lymph nodes.

  • Genitourinary TB: Affects the kidneys or reproductive and urinary systems.

Symptoms

Symptoms depend on the site of infection and may include:

  • Persistent fever.

  • Weight loss and fatigue.

  • Enlarged lymph nodes.

  • Localised pain or swelling.

  • Neurological symptoms in central nervous system involvement.

  • Abdominal discomfort or swelling.

  • Organ-specific symptoms.

Not every patient experiences the same symptoms.

Diagnosis

Diagnostic methods may include:

  • Clinical assessment and medical history.

  • Imaging such as ultrasound, X-ray, CT, or MRI.

  • Examination of relevant tissue or fluid samples.

  • Molecular tests, including appropriate nucleic acid amplification tests.

  • Histopathology and culture where indicated.

A negative test does not always exclude extra-pulmonary TB because the number of bacteria in some specimens may be low.

Treatment and public-health significance

Treatment generally involves combinations of anti-tuberculosis medicines under appropriate clinical guidance. The regimen and duration depend on the site of disease, drug susceptibility, and relevant national guidelines.

UPSC Prelims Key Pointers

  • TB is caused primarily by Mycobacterium tuberculosis.

  • Extra-pulmonary TB affects sites outside the lungs.

  • Pulmonary and extra-pulmonary TB can occur together.

  • TB meningitis is a serious form of extra-pulmonary TB.

  • Drug-resistant TB requires appropriate drug-susceptibility assessment and treatment.

  • India implements the National TB Elimination Programme.

  • TB is an infectious disease, but the likelihood and route of transmission depend on the site of disease; pulmonary and laryngeal TB are particularly important sources of airborne transmission.