2.1 Pulmonary tuberculosis

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    Prolonged cough (more than 2 weeks), with or without sputum production, is a common symptom in patients with pulmonary tuberculosis (PTB). 

     

    Other frequent, less specific, signs and symptoms include weight loss, anorexia, fatigue, haemoptysis (blood in sputum), shortness of breath, chest pain, moderate fever and night sweats.

     

    Signs and symptoms may vary between individuals and generally evolve in a chronic, insidious manner. History-taking is therefore of the utmost importance.

     

    Advanced forms and complications are common:

    • Respiratory insufficiency due to extensive lesions and destroyed lungs;
    • Massive haemoptysis due to large cavities with hyper-vascularisation and erosion of vessels;
    • Pneumothorax due to the rupture of a cavity in the pleural space.

     

    In endemic areas, the diagnosis of PTB should be considered in any patient consulting for respiratory symptoms lasting more than 2 weeks.

     

    Table 2.1 provides a differential diagnosis of PTB for non-HIV infected patients.

     

    Table 2.1 - Differential diagnosis for PTB (non-HIV infected patients)

     

    Diseases

    Remarks

    Bacterial pneumonia

    • Usually more acute and shorter in duration; high fever often present.
    • Response to antibiotics with no anti-TB activity suggests bacterial pneumonia.
    • Lobar consolidation is typical of bacterial pneumonia; however, CXR alone cannot differentiate PTB from bacterial pneumonia.

    Pulmonary abscess

    • May arise from aspiration in individuals with impaired consciousness (coma, intoxication with alcohol/drugs, etc.).
    • Foul-smelling, purulent sputum.
    • Cavities typically have a thick wall and air fluid levels.

    Bronchiectasis

    • Frequent complication of successive, poorly-treated bronchopulmonary infections in tropical regions.
    • Characterised by chronic or repeated episodes of productive cough.
    • Hemoptysis, usually mild, can be present.

    Lung cancer

    • History of smoking or environmental exposure (working in a mine, etc.).
    • Haemoptysis in 20 to 50% of patients.

    Paragonimiasis
    (lung flukes)

    • To be ruled out in presumed PTB cases in endemic areas (certain areas of Southeast Asia, West Africa and Latin America).

    Pulmonary echinococcosis
    (hydatid disease)

    • In Latin America, the Middle East, some Sub-Saharan African countries and China.
    • Lung involvement may cause chronic cough, with or without haemoptysis.
    • Cysts can mimic TB cavities.

    Pneumocystosis

    • Common in patients with advanced HIV disease and patients receiving long-term, even low dose, corticosteroid therapy.

    Less common diseases

    • Silicosis, sarcoidosis, melioidosis.
    • Cryptococcosis, aspergillosis, histoplasmosis.

     

    For differential diagnosis in HIV-infected patients see Section 2.4.