TB Flashcards
What factors increase the likelihood of someone having TB? (6 things)
- Hx prior TB exposure / treatment
- Low immunity (HIV)
- Travel to area where TB is endemic
- Homelessness
- Jail / IV drug use
- Gastrectomy
What are the classical features of pulmonary TB? (7 things)
- Fever
- Night sweats
- Fatigue
- Cough
- Haemoptysis
- Chest pain
- Weight loss / anorexia
What is the bacteria that causes TB?
Myobacterium tuberculosis
When does active infection of TB occur?
Inadequate containment by immune system (T cells / macrophages)
What 2 things can active infection of TB arise from?
- Primary infection
2. Reactivation of latent disease
What is latent TB?
Infection without disease
Because contained by immune system (e.g granuloma formation prevents bacteria growth + spread)
What tests will show up positive / negative in latent TB?
Positive: skin / blood tests
Negative: Sputum / CXR
What are the risk factors for reactivating latent TB?
- New infection
- HIV
- Organ transplant
- Immunosuppression
- Homeless / jail
What are the systemic clinical features of TB? (7 things)
- Fever (low grade)
- Anorexia
- Malaise
- Weight loss
- Night sweats
- Erythema nodosum (red + swollen fat under skin)
- Clubbing (bronchiectasis)
FAM W NEC
What are the clinical features of PULMONARY TB? (4 things)
- Cough (dry then productive)
- Haemoptysis
- Pleurisy (inflamm pleura)
- Pleural Effusion
What are the clinical features of Tuberculus Lymphadenitis? (2 things)
- Painless enlargement of cervical / supraclavicular lymph nodes
- Systemic symptoms (FAM W NEC)
What are the nodes like in Tuberculus Lymphadenitis?
Firm to touch and NOT acutely inflamed
Does Tuberculus Lymphadenitis occur with PULMONARY TB?
Yes and can also occur without
How is Tuberculus Lymphadenitis investigated? (3 things)
- Fine needle aspiration
- AFB staining (sputum stain for Mycobacteria)
- Culture
FAC
What are the clinical features of GASTROINTESTINAL TB? (3 things)
- Vomiting
- Colicky abdominal pain
- Bowel obstruction (bc bowel wall thickening / stricture)
What is required for the diagnosis of GASTROINTESTINAL TB?
Biopsy
What distinguish GASTROINTESTINAL TB from Crohn’s disease? (2 things)
Caseation necrosis
Absence of transmural cracks
What are the clinical features of SPINAL TB? (4 things)
- Pain + bony tenderness for weeks / months
- Bony destruction / vertebral collapse
- Soft tissue abscess
- Slow progression
What is Miliary TB?
When haematogenous dissemination leads to formation of foci of granulomatous tissue (2mm) on lung
Potentially fatal form of TB
What is CNS TB?
Haematogenous spread leading to foci of infection in brain + spinal cord
What do foci of CNS TB enlarge to form?
Tuberculomas
What does foci of CNS TB rupture lead to?
Meningitis
What should you check the CSF for in CNS TB? (4 things)
- Leucocytosis
- Raised protein
- Plasma glucose <50%
- AFB stain, PCR & culture
What are the clinical features of GENITOURINARY TB? (5 things)
- Dysuria
- Frequency
- Loin pain
- Haematuria
- Sterile pyuria (WBC in urine)
What can granulomas in GENITOURINARY TB cause?
- Fibrosis
- Strictures
- Infertility
- Genital ulceration
What does CARDIAC TB involve?
Pericardium (pericarditis, pericardial effusion, constrictive pericarditis)
What are the diagnostic tests for latent TB? (2 things)
- Tuberculin skin testing (TST) (aka Mantoux test)
2. Interferon-gamma release assays (IGRAS)
What reduces sensitivity of both latent TB tests?
Immune suppressed states
What are the diagnostic tests for active TB? (4 things)
- CXR
- Sputum smear
- Sputum culture
- Nucleic acid amplification test (NAAT)
What is seen in a CXR in active TB? (4 things)
- Cavitation (mainly upper lobe if reactivated TB)
- Calcification
- Effusion (yh)
- Lymphadenopathy
(Caseating necrosis seen in histology)