TB Flashcards
(26 cards)
What are some pulmonary features of pulmonary TB?
Cough
Haemoptysis
SOB
Chest pain
Prolonged (>3 weeks) LRTI
Symptoms resistant to Abx
What are some systemic features of pulmonary TB?
Weight loss Low grade fever Night sweats (very specific for TB) Fatigue Malaise Enlarged lymph nodes
How would you investigate pulmonary TB?
Sputum (microscopy + smear) - Ziehl Neelsen stain (test for acid fast bacilli) - instant results Sputum culture - 2 - 3 weeks to return
Chest X-ray
Give 3 features of pulmonary TB you might see on a Chest X-ray
Hilar lymphadenopathy
Apical lobe consolidation
Apical lobe cavitation
Fibrosis (Ghon complex becoming Ranke complex)
What are the 4 meds for pulmonary TB? And how long are they given for?
Rifampicin
Isoniazid
Pyrazinamide
Ethambutol
2 months of everything
then 4 months of rifampicin and isoniazid
(Pyrazinamide and Ethambutol are given for 2 months only)
Side effect of rifampicin?
Red urine
Hepatitis
CYP450 inducer
Side effect of isoniazid?
B6 depletion –> peripheral neuropathy
Hepatitis
Side effect of pyrazinamide?
Hepatitis
Arthralgia/Gout
Rash
Side effect of ethambutol?
Optic neuritis
What is the term of therapy to ensure adherence?
Directly Observed Therapy (DOTS)
What test(s) would you perform to determine exposure to TB but will not differentiate between active or latent TB?
Mantoux test
IFN-gamma release assay
- Quantiferon –> looks at IFNy release
- T spot –> measure IFNy-producing T cells
When would you get a false negative result for the Mantoux test?
Immunosuppression: HIV, Steroid usage Sarcoidosis Lymphoma Hypoalbuminaemia Anaemia
What do you call the granulomatous inflammation in TB?
Ghon focus
What do you call a Ghon focus with lymphadenopathy?
Ghon complex
What do you call a Ghon complex which undergoes fibrosis and calcification?
Ranke complex
What might you see in a CXR to indicate old TB?
Calcified nodule
Can the Mantoux test differentiate between TB and BCG vaccine?
Yes and no.
If the size of the induration is high enough, suggests exposure to TB
What type of necrosis is TB?
Caseating necrosis
What drug is used for chemoprophylaxis for latent TB and what is the duration?
6 months of isoniazid.
3 months of rifampicin and isoniazid
66% of these patients won’t get relapse of TB
What are some drugs you can give in MDR-TB?
Clofazimine
Bedaquilline
Pretomanid
Linezolid
What the most common sites for extrapulmonary TB?
Lymph node (most common)
Pleural
Genitourinary
Mechanism of action of rifampicin?
Interferes with nucleic acid synthesis
Mechanism of action of isoniazid?
Inhibits mycolic acid synthesis
Mechanism of action of pyrazinamide?
Inhibits fatty acid synthesis
