Tuberculosis

Question 1

Define Tuberculosis (TB)?

Answer 1

Granulomatous disease caused by Mycobacterium tuberculosis

Question 2

What is Primary TB?

Answer 2

Initial infection may be pulmonary or (more rarely) gastrointestinal

Question 3

What is Miliary TB?

Answer 3

Results from haematogenous dissemination of TB

Question 4

What is Post-Primary TB?

Answer 4

Caused by reinfection or reactivation

Question 5

What is the aetiology of TB?

Answer 5

Mycobacterium tuberculosis is an intracellular organism

It survives after being phagocytosed by macrophages

Question 6

What is the epidemiology of TB?

Answer 6

Annual mortality = 3 million (95% in developing countries)
Annual UK incidence = 6000
Asian immigrants are the highest risk group in the UK

Question 7

What are the symptoms and signs of Primary TB?

Answer 7

Mostly asymptomatic 
Fever
Malaise 
Cough
Wheeze 
Erythema nodosum 
Phlyctenular conjunctivitis

Question 8

What are the symptoms and signs of Miliary TB?

Answer 8

Fever
Weight loss
Meningitis
Yellow caseous tubercles spread to other organs

Question 9

What are the symptoms and signs of Post-Primary TB?

Answer 9

Fever/night sweats
Malaise 
Weight loss 
Breathlessness 
Cough 
Sputum 
Haemoptysis 
Pleuritic chest pain 
Signs of pleural effusion 
Collapse 
Consolidation 
Fibrosis

Question 10

Who does Non-Pulmonary TB normally affect?

Answer 10

The immunocompromised

Question 11

What are the effects on the Lymph nodes as a result of TB?

Answer 11

Suppuration of cervical lymph nodes leading to abscesses or sinuses

Question 12

What are the CNS symptoms and signs of TB?

Answer 12

Meningitis

Tuberculoma

Question 13

What are the symptoms and signs on the skin of TB?

Answer 13

Lupus vulgaris (jellylike reddish-brown glistening plaques

Question 14

What are the symptoms and signs on the heart as a result of TB?

Answer 14

Pericardial effusion

Constrictive pericarditis

Question 15

What are the GI symptoms and signs of TB?

Answer 15

Subacute obstruction 
Change in bowel habit 
Weight loss 
Peritonitis 
Ascites

Question 16

What are the Genitourinary symptoms and signs of TB?

Answer 16

UTI symptoms 
Renal failure 
Epididymitis 
Endometrial or tubal involvement 
Infertility

Question 17

What are the Bone/Joint symptoms and signs of TB?

Answer 17

Osteomyelitis
Arthritis
Vertebral collapse (Pott’s disease)
Spinal cord compression from an abscess

Question 18

Why do we do Sputum/Pleural Fluid/Bronchial Washings for TB?

Answer 18

MC&S

Culturing TB takes a long time (around 6 weeks)

Question 19

Why do we do Tuberculin Tests for TB?

Answer 19

Positive if the patient has had previous exposure to M.tuberculosis or BCG

Question 20

What is the Mantoux Test?

Answer 20

A purified protein derivative (PPD) is injected intradermally
Erythema occurs after 72 hrs

Question 21

What is the Heaf Test?

Answer 21

Place a drop of PPD on the forearm
Fire a spring-loaded needle gun
Check again after 3-7 days
Graded according to papule size and vesiculation

Question 22

Why do we do Interferon Gamma Tests for TB?

Answer 22

Useful in latent TB

Exposure of host T cells to TB antigens leads to release of interferon

Question 23

What do we see on a CXR for Primary Infection of TB?

Answer 23

Peripheral consolidation

Hilar lymphadenopathy

Question 24

What do we see on a CXR for Miliary Infection of TB?

Answer 24

Fine shadowing

Question 25

What do we see on a CXR for Post-Primary TB?

Answer 25

Upper lobe shadowing 
Streaky fibrosis and cavitation 
Calcification 
Pleural effusion 
Hilar lymphadenopathy

Question 26

What other investigations can we do for TB?

Answer 26

HIV Testing 
CT
Lymph Nodes 
Pleural biopsy 
Sampling of other affected systems