12. TB Flashcards
What is Tuberculosis
an infectious disease caused by the mycobacterium tuberculosis bacteria
it is a small rod shaped bacteria (a bacillus)
they are also resistant to the acids using in staining procedures so described as acid-fast bacilli
acid fast bacilli that stain red with Zeihl-Neelson stains is what organisms
mycobacterium tuberculosis
where is TB more prevalent
non-UK born patients (ie from South Asia)
those who are immunocompromised (ie HIV) and those with close contacts with TB
where is the most common site for TB infection and why
the lungs where they get plenty of oxygen
extra pulmonary TB is where it infects other areas ;
name some other areas
lymph nodes 'a cold abscess' is a firm painless abscess caused by TB usually in the neck pleura CNS pericardium GI system GU systemm cutaneous TB affecting the skin
what are the risk factors for TB
- Known contact with active TB
- Immigrants from areas of high TB prevalence
- People with relatives or close contacts from countries with a high rate of TB
- Immunosuppression due to conditions like HIV or immunosuppressant medications
- Homeless people, drug users or alcoholics
What test is used prior to having the BCG vaccine
Mantoux test
what are the typical signs and symptoms of TB
- Lethargy
- Fever or night sweats
- Weight loss
- Cough with or without haemoptysis
- Lymphadenopathy
- Erythema nodosum
- Spinal pain in spinal TB (also known as Pott’s disease of the spine)
what does the Mantoux test look for
previous immune response to TB and this indicates possible previous vaccination, latent or active TB
on a CXR what does primary TB look like
patchy consolidation, pleural effusions and hilar lymphadenopathy
on a CXR what does reactivated TB look like
patchy or nodular consolidation with cavitation (gas filled spaces in the lungs) typically in the upper zones
on a CXR what does disseminated biliary TB look like
millet seeds uniformly distributed throughout the lung fields
what is the management of active TB
Mnemonic RIPE
4 drugs • R – Rifampicin for 6 months • I – Isoniazid for 6 months • P – Pyrazinamide for 2 months • E – Ethambutol for 2 months
What medication is prescribed alongside TB medications in order to prevent peripheral neuropathy caused by the isoniazid
pyridoxine (vitamin B6)
what is the main side effect of rifampicin
red/orange discolouration of urine and tears
