5.2. Tuberculosis (TB)

📄 Definition

Tuberculosis (TB) is a chronic infectious disease caused by Mycobacterium tuberculosis, commonly affecting the lungs (pulmonary TB) but may involve any organ (extrapulmonary TB).

🔬 Pathophysiology

  • Inhaled droplets → alveolar macrophage phagocytosis

  • Formation of granulomas (caseating necrosis)

  • Can be:

    • Latent TB – asymptomatic, non-infectious

    • Active TB – symptomatic, infectious

  • Reactivation common in immunosuppressed

📋 Risk Factors

🧠 Mnemonic: CLOSE CONTACT

  • Contact with known TB case

  • Low immunity (HIV, diabetes, cancer, steroids)

  • Overcrowded living (hostels, prisons)

  • Socioeconomic deprivation

  • Endemic area travel/residence (Africa, SE Asia)

  • Chronic renal failure

  • Organ transplant

  • Nutritional deficiency

  • Teenagers or elderly

  • Alcohol misuse

  • Chemotherapy

  • Tobacco smoking

📋 Clinical Features

🧠 Mnemonic: CLAPS

  • Cough >3 weeks (± haemoptysis)

  • Low-grade fever (especially evening)

  • Anorexia and weight loss

  • Profuse night sweats

  • SOB and pleuritic chest pain

🩺 Physical Examination Findings

  • Cachexia, pallor, lymphadenopathy

  • Finger clubbing

  • Crackles/bronchial breathing

  • Spinal tenderness (if Pott’s disease)

  • Signs of effusion or consolidation

🔍 Investigations

🧠 Mnemonic: SPUTUM CXR TEST

  • Sputum: 3 early-morning samples → Ziehl-Neelsen stain, culture (8 weeks), PCR

  • CXR: upper lobe infiltrates ± cavitation, hilar lymphadenopathy

  • Mantoux test (tuberculin skin test)

  • IGRA (Interferon Gamma Release Assay) – e.g. T-Spot TB

  • HIV test

  • FBC, LFTs – baseline for treatment

  • CT/MRI – for extrapulmonary TB

  • Pleural aspirate/biopsy – if pleural TB suspected

Extrapulmonary TB (EPTB)

🧠 Mnemonic: SPINE

  • Spinal TB (Pott’s disease)

  • Pericardial TB

  • Intestinal TB

  • Neuro TB (meningitis)

  • Effusions (pleural, peritoneal, joint)

🧾 Management

🧠 Mnemonic: RIPE

  • Rifampicin

  • Isoniazid

  • Pyrazinamide

  • Ethambutol
    Duration:

  • 6 months (RI for 6m, PE for 2m) for standard pulmonary TB

  • 12 months for CNS/spinal TB

💊 Co-prescribe pyridoxine (vitamin B6) with isoniazid to prevent neuropathy

🛡️ Public Health:

  • Notifiable disease

  • Close contact tracing

  • DOT (Directly Observed Therapy) if adherence is a concern

  • Consider isolation if smear-positive

⚠️ Side Effects of Treatment

🧠 Mnemonic: RIPE SIDE

  • Rifampicin – red/orange secretions, hepatotoxicity

  • Isoniazid – neuropathy, hepatitis

  • Pyrazinamide – gout, hepatotoxic

  • Ethambutol – optic neuritis (visual testing needed)

🧐 Differentials

🧠 Mnemonic: CHILD COUGH

  • Cancer

  • Histoplasmosis

  • Interstitial lung disease

  • Lung abscess

  • Drug reaction (ACE-i)

  • COPD

  • Oesophageal reflux

  • Urinary TB (if systemic)

  • Granulomatosis (e.g. sarcoidosis)

  • HIV-related opportunistic infection

📌 PARA Revision Tips

  • Always isolate suspected smear-positive TB

  • Weight loss + night sweats + cough >3 weeks = TB unless proven otherwise

  • Know the RIPE regimen, duration, and public health actions

  • CXR + sputum + IGRA/Mantoux = triple approach

  • Risk of reactivation high in HIV/steroid use

🔎 Last updated in line with NICE NG33 – Tuberculosis
Published: January 2016 • Last updated: September 2019
Last reviewed: July 2025
🔒 PASSMAP ensures all content is NICE-aligned and reviewed for Physician Associate Registration Assessment (PARA) success.

Scroll to Top