Extrapulmonary Tuberculosis - Symptoms, Causes, Treatment & Prevention

Overview

Extrapulmonary tuberculosis (TB) refers to Mycobacterium tuberculosis infection that occurs outside the lungs. While the bacterium most commonly affects the respiratory tract, it can spread through the bloodstream or lymphatic system to virtually any organ, including the lymph nodes, pleura, bones and joints, genitourinary tract, meninges, and skin.

Extrapulmonary TB accounts for ~15–20 % of all reported TB cases in high‑income countries, but the proportion rises to 30–40 % in immunocompromised patients, especially those living with HIV. Worldwide, the World Health Organization (WHO) estimates **10 million** new TB cases annually; about **1.5 million** (15 %) are extrapulmonary ¹. The disease can affect anyone, but children <5 years, people with HIV, and individuals receiving immunosuppressive therapy are at highest risk.

Symptoms

Because TB can involve any organ, symptoms vary widely. Below is a comprehensive list grouped by the most common sites of involvement.

Lymphatic (most frequent form)

• Enlarged, painless lymph nodes—often in the neck (cervical tuberculous lymphadenitis, “scrofula”).
• Node may become tender, fluctuant, or develop a sinus tract that drains pus.

Pleural (lung lining)

• Sharp chest pain that worsens with deep breathing.
• Fever, night sweats, and shortness of breath.
• Dry cough; pleural effusion may cause a feeling of “fullness” in the chest.

Bone and Joint (Pott disease)

• Persistent back or neck pain, often worsening at night.
• Reduced range of motion, spinal deformities (e.g., kyphosis).
• Swelling and warmth over affected joints.

Genitourinary (kidney, bladder, prostate, reproductive organs)

• Flank or lower abdominal pain.
• Blood in urine (hematuria) or painful urination.
• Infertility or pelvic pain in women.

Meningeal (TB meningitis)

• Severe, persistent headache.
• Neck stiffness, photophobia.
• Altered mental status, seizures, or cranial nerve palsies.
• Fever and vomiting.

Abdominal (peritoneal, intestinal)

• Abdominal pain or distension.
• Weight loss, loss of appetite.
• Diarrhea or constipation; occasional intestinal obstruction.

Skin (cutaneous TB)

• Ulcerated or nodular lesions, often on the face, arms, or legs.
• Lesions may be painless or tender and can form sinus tracts.

Other organs (eye, ear, breast, etc.)

• Visual disturbances, eye pain, or uveitis.
• Ear pain, hearing loss, or facial nerve palsy.
• Lump in the breast that mimics cancer.

Systemic features such as **fever, night sweats, unexplained weight loss, and fatigue** are common across most forms of extrapulmonary TB.

Causes and Risk Factors

Extrapulmonary TB occurs when M. tuberculosis spreads beyond the lungs. This dissemination can happen during the initial lung infection (primary TB) or later when a pulmonary focus reactivates.

Primary Causes

• Inhalation of airborne droplets containing TB bacilli.
• Hematogenous spread (through the bloodstream) to distant organs.
• Direct extension from a nearby infected lymph node or bone.

Key Risk Factors

• HIV infection – Reduces cell‑mediated immunity; up to 50 % of TB in HIV‑positive patients is extrapulmonary.
• Young age – Children, especially under 5 years, have immature immune responses.
• Immunosuppressive therapies – Corticosteroids, TNF‑α inhibitors (e.g., infliximab), chemotherapy.
• Malnutrition – Impairs immune function.
• Diabetes mellitus – Increases susceptibility and can worsen disease severity.
• Recent travel or residence in high‑TB‑burden regions (e.g., South‑East Asia, sub‑Saharan Africa).
• Close contact with active TB cases – Household members, healthcare workers.

Diagnosis

Diagnosing extrapulmonary TB is often more challenging than pulmonary TB because symptoms are less specific and bacilli are harder to detect. A combination of clinical suspicion, imaging, laboratory tests, and tissue sampling is usually required.

Step‑by‑step diagnostic pathway

1. Medical history and physical exam – Assess risk factors, symptom pattern, and organ‑specific signs.
2. Baseline laboratory tests
   • Complete blood count (CBC) – May show anemia or leukocytosis.
   • Erythrocyte sedimentation rate (ESR) or C‑reactive protein (CRP) – Often elevated.
   • HIV test – Recommended for all suspected TB cases.
3. Imaging studies
   • Chest X‑ray – May be normal or show residual pulmonary lesions.
   • CT or MRI – Preferred for spinal, meningeal, or abdominal disease.
   • Ultrasound – Useful for lymph node, pleural, or abdominal fluid assessment.
   • PET‑CT – Occasionally used for difficult cases.
4. Microbiologic confirmation
   • Acid‑fast bacilli (AFB) smear – Low sensitivity for extrapulmonary samples.
   • Culture (solid or liquid media) – Gold standard, but may take 2‑6 weeks.
   • Nucleic acid amplification tests (NAATs) – GeneXpert MTB/RIF and similar assays provide results within hours and detect rifampin resistance.
   • Histopathology – Granulomatous inflammation with caseating necrosis is characteristic, though not exclusive to TB.
5. Site‑specific procedures
   • Lymph node excisional or core needle biopsy.
   • Thoracentesis for pleural effusion analysis (ADA level, PCR).
   • Lumbar puncture for CSF analysis in suspected meningitis (high protein, low glucose, lymphocytic pleocytosis).
   • Bone biopsy or image‑guided aspiration for spinal disease.

Clinical guidelines from the CDC and WHO recommend confirming TB whenever possible before starting long‑term therapy, but empirical treatment may be started if the suspicion is high and delay would risk serious complications.

Treatment Options

Standard anti‑TB chemotherapy is effective for extrapulmonary disease, but regimens may be longer or require adjunctive procedures based on the organ involved.

First‑line drug regimen

• Isoniazid (INH) – 5 mg/kg (max 300 mg) daily.
• Rifampin (RIF) – 10 mg/kg (max 600 mg) daily.
• Pyrazinamide (PZA) – 15–30 mg/kg daily.
• Ethambutol (EMB) – 15–25 mg/kg daily.

This intensive phase lasts **2 months**, followed by a continuation phase of **INH + RIF** for **4–7 months**. For most extrapulmonary sites, the total duration is **6–9 months**; however, certain forms (e.g., TB meningitis, spinal TB) often require **12 months** of therapy.

Adjunctive treatments

• Corticosteroids – Recommended for TB meningitis, pericardial TB, and severe pleural effusions (e.g., dexamethasone 0.4 mg/kg daily, taper over 6–8 weeks).
• Surgical intervention – Indicated for:
  • Abscess drainage (brain, spinal, or abscesses).
  • Debridement of infected bone or joints.
  • Pleural fluid evacuation or thoracoscopic decortication.
• Supportive care – Nutritional supplementation, management of comorbidities (HIV antiretroviral therapy, diabetes control).

Drug‑resistant TB

If NAAT or culture shows resistance (e.g., multidrug‑resistant TB, MDR‑TB), a regimen containing second‑line agents (fluoroquinolones, injectables, bedaquiline, delamanid) is required, typically for 18–24 months. Management should be coordinated through a specialized TB program.

Living with Extrapulmonary Tuberculosis

Successful treatment hinges on adherence, monitoring, and lifestyle modifications.

• Medication adherence – Use a daily pillbox, set alarms, or enroll in Directly Observed Therapy (DOT) if recommended.
• Follow‑up appointments – Regular visits for liver function tests (INH, RIF, PZA can be hepatotoxic) and drug‑level monitoring.
• Nutrition – High‑protein, calorie‑dense diet supports immune recovery; consider supplements (vitamin D, B‑complex) after discussing with a clinician.
• Alcohol and tobacco – Avoid both; they increase hepatotoxic risk and impair immune response.
• Physical activity – Light to moderate exercise improves stamina; avoid heavy lifting if spinal TB is present until cleared by a specialist.
• Infection control – Most extrapulmonary TB patients are not infectious, but if a concurrent pulmonary focus exists, wear a mask and practice good cough etiquette.
• Psychosocial support – Stigma can be significant. Seek counseling, support groups, or community health worker assistance.

Prevention

Because extrapulmonary TB stems from the same organism as pulmonary TB, primary prevention mirrors that of classic TB.

• BCG vaccination – Provides variable protection against severe TB forms (meningitis, miliary TB) in children; recommended in high‑burden countries.
• Screening of high‑risk contacts – Prompt tuberculin skin test (TST) or interferon‑γ release assay (IGRA) for household members and healthcare workers.
• Latent TB infection (LTBI) treatment – Isoniazid for 6–9 months or rifampin for 4 months in persons with a positive TST/IGRA and risk factors.
• Infection control in healthcare settings – Negative‑pressure rooms, N95 respirators, rapid isolation of suspected pulmonary TB cases.
• Public health measures – Improve ventilation in congregate settings (prisons, shelters), and ensure completion of therapy through DOT programs.

Complications

If left untreated or inadequately treated, extrapulmonary TB can cause irreversible damage.

• Neurologic deficits – From TB meningitis (hydrocephalus, seizures, cranial nerve palsies).
• Spinal deformities – Kyphosis, vertebral collapse, paraplegia.
• Chronic kidney failure – From extensive genitourinary involvement.
• Infertility – Scarring of reproductive organs in both men and women.
• Pericardial constriction – Restrictive cardiomyopathy leading to heart failure.
• Sepsis and multi‑organ failure – In disseminated (miliary) disease.
• Drug‑induced toxicity – Hepatotoxicity, optic neuritis (ethambutol), peripheral neuropathy (isoniazid).

When to Seek Emergency Care

Early intervention can prevent permanent organ damage and improve outcomes.

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Sources: 1. World Health Organization. Global Tuberculosis Report 2023. 2. CDC. Tuberculosis (TB) – Extrapulmonary TB. 3. Mayo Clinic. Tuberculosis – Symptoms and causes. 4. NIH, National Institute of Allergy and Infectious Diseases. Treatment of TB. 5. Cleveland Clinic. Extrapulmonary Tuberculosis. 6. Lancet Respir Med. 2022;10:879‑892.