Tuberculosis Flashcards
what is tuberculosis?
chronic granulomatous disease caused by mycobacterium tuberculosis
what is psoas sign?
pain when patient lies on their left side while the right thigh is flexed backwards
what does psoas sign indicate?
possible psoas abscess
what is the standard management regimen for TB?
- isoniazid + rifampicin + ethambutol + pyrazinamide for 2 months
- isoniazid + rifampicin for 6 months
duration extended if cerebral involvement or pericarditis
what are the side-effects of isoniazid?
- peripheral neuropathy
- liver toxicity
what medication is given to prevent peripheral neuropathy secondary to isoniazid?
pyridoxine (vitamin B6)
what are the side-effects of rifampicin?
- liver toxicity
- hepatic enzyme (p450) inducer
- turns bodily fluids red/orange colour
what are the side-effects of ethambutol?
- visual disturbance
- avoid in chronic kidney disease
what are the side-effects of pyrazinamide?
liver toxicity
most hepatotoxic of all TB medications
what diagnosis should be investigated in all cases of TB?
HIV
what is a mantoux test?
tuberculin skin test
postive >/= 5mm induration
what is given the mantoux test?
contacts of TB
when in mantoux test positive?
- active TB
- previous BCG vaccination
who should receive the BCG vaccination?
tuberculin skin test negative (mantoux negative) contact of TB who is either:
* <35 years old
* >35 years old and work in healthcare
what TB medication is most likely to cause hepatotoxicity?
pyrazinamide
how is TB transmitted?
inhalation droplets infected with mycobacterium tuberculosis
what are the clinical features of TB?
- night sweats
- fever
- weight loss
- other systemic symptoms
what are the risk factors for TB?
- ethnic minority groups
- homelessness
- drug and alcohol abuse
- close contact with infected patient
- immunosuppression
- young or old age
where is TB typically seen in the lungs?
apex
what investigations are undertaken in suspected TB?
- chest x-ray
- sputum samples for culture and sensitivity testing
- samples from non-pulmonary sites
- samples are stained with Ziehl-Heelsen or auramine staining
- for culture - Lowenstein-Jensen (LJ) media is needed
- PCR
- interferon-gamma release assays (IGRAs)
- mantoux test
what are the typical findings on chest x-ray in TB?
cavitating lesion in the apex
what is pott’s disease?
tubercular spondylitis
- localised back pain
- neurological deficits
- radiographic findings indicative of vertebral body involvement
- biopsy demonstrating granuloma formation
