TB Flashcards
What is it
Granulomatous disease that may affect any organ, but most commonly affects the lung
Why does Tuberculosis mainly affect the lung
since it is transmitted via aerosol droplets
Cause
Mycobacterium tuberculosis (acid-fast bacillus)
Pathophysiology of Primary pulmonary TB
Initial TB infection
Ghon focus formation in upper lobes
Hilar lymphadenopathy
Pathophysiology of Secondary pulmonary TB
Occurs after primary infection
Dormant TB is reactivated
Fibrocaseous lesions
Other forms of TB (not primary or secondary pulmonary)
Miliary Genitourinary Bone e.g. Pott's disease of the spine Peritoneal Meningitis
Signs and symptoms
Cough Haemoptysis Weight loss Night sweats Fever
Complications
Dissemination to other organs
Death
Investigations
Sputum culture: (Ogawa/Lowenstein-Jensen medium)
Sputum stain: Ziehl-Neelsen stain
Transbronchial biopsy - Granulomas are diagnostic
Pleural fluid for analysis and biopsy
Radiology
What is seen on CXR
Infiltrates and cavitations
In miliary TB, lesions described as millet seeds
Which investigation assesses for granulomas (diagnostic)
Transbronchial biopsy
Conservative treatment
Patient education, especially the importance of complying with medical therapy
Medical treatment
RIPE: Rifampicin Isoniazid Pyrazinamide Ethambutol
Also maybe streptomycin, quinolones, amikacin, capreomycin
Surgical treatment
Depends on location
e.g. Pulmonary TB, consider Lobectomy
**Describe mode of infection of pulmonary TB in NON immunocompotent (immuno comprimised) patients
Droplets inhaled
Bacteria colonise alveoli
Bacteria engulfed by macrophages
Multiplication of bacteria within macrophages
Granulomas form around M.tuberculosis (caseous necrosis)
[Non-immunocompetent patients:]
Granuloma formation does not contain bacteria
Liquefaction of necrotic tissue
Coughing of infectious droplets since the liquified necrotic tissue drains into the bronchus
