TB Flashcards
Primary tuberculosis
Non immune host exposed to mycobacterium tuberculosis
Commonly affects lungs
Ghon focus development
Normally heals with fibrosis
In immunocompetent may become disseminated
Ghon complex
Ghon focus (TB laden macrophages) + hilar lymph nodes
Secondary TB
Host becomes immunocompromised
Latent infection reactivates
Common site of lung TB
Apex of the lungs
Extra - pulmonary TB
CNS - tuberculous meningitis Vertebral bodies - Pott’s disease Cervical lymph nodes - scrofuloderma Renal GI
Risk factors for reactivation
HIV
Malnourishment
Organ transplant
Taking immunosuppressants
Screening
Mantoux test
Interferon gamma test
Can’t differentiate between latent and active disease
Mantoux test - can’t differentiate if vaccinated
Presentation
Haemoptysis Pleuritic chest pain Weight loss Night sweats Recent travel - especially South Asia
Ix
Respiratory exam
Basic obs
Bloods - FBC, U+Es, LFTs, CRP
3x early morning sputum cultures with ziehl Neelsen stain
NAAT
CXR
ABG
Mx
2 months of:
- Rifampcin
- Isoniazid
- pyrazinamide
- ethambutol
Further 4 months of:
- Rifampcin
- Isoniazid
Side effects of TB drugs
- Rifampcin - hepatitis, orange secretions
- Isoniazid - hepatitis, peripheral neuropathy, agranulocytosis
- pyrazinamide - hepatitis, arthralgia, gout
- ethambutol - optic neuritis
How to prevent peripheral neuropathy when taking TB medication
Give vitamin B6
Test to do before TB drugs are given
Visual acuity test and colour blind check
Treatment of latent TB
3 months of isoniazid And Rifampcin
Or
6 months of isoniazid
Meninges tuberculosis Mx
Treated for at least 12 months
- steroids
