1. Tuberculosis Signs
Crepitations ± Signs of fibrosis ± Signs of effusion
Signs of consolidation ± Signs of pneumothorax
Pathology
Infection → Type IV hypersensitivity rxn → Acute inflammatory response by neutrophils fail 2) Miliary TB
to deal with MTB → Chronic inflammatory response by macrophages → Granuloma Persistent cough Tachycardia Fever
formation. SOB Anaemia LOW
Primary TB: Crepitations Hepatosplenomegaly Night sweats
o First exposure, usually asymptomatic. Resulting in formation of Ghon focus in Choroidal tubercles on ophthalmoscopy Lympadenopathy
inferior upper lobe or superior lower lobe of lungs + spread to bronchial or hilar
LNs to form Ghon complex. 3) Extra-pulmonary TB
o If immune response is poor, primary TB may spread by various routes: 1. GI – Diarrhoea Peritoneal fluid for AFB
1. Progressive Pulmonary TB – direct spread. intestine or Malabsorption
2. Tuberculous pleurisy – rupture through visceral pleura / spread through peritoneum I/O
lymphatics. May result in pleural effusion or empyema. Ascites
3. Tuberculous pericarditis – spread through lymphatics 2. Pericardium Pericardial effusion or tamponade Requires steroids to
4. Bronchopneumonia – rupture through bronchial walls Constructive pericarditis due to post- reduce need for
5. Miliary TB – rupture through blood vessel walls. May cause TB infectious fibrosis pericardiectomy
meningitis. 3. GU Haematuria 3 early morning urine
6. Collapse - Large tuberculous mediastinal LN may compress lobar or Frequency for AFB
segmental bronchus. Dysuria Renal U/S
Secondary TB: Sterile pyuria IVU
o Source of infection: usually reactivation of dormant TB from healed primary lesion. Salpingitis
o Usually at apices of lungs Tubal abscess
o May heal by fibrosis resulting in tubercle formation, or may spread if immune Epididymal TB – swelling / sinus
response is poor. Route of spread as above. formation
o Complications: 4. CNS Headache CSF for AFB – fibrin
1. Pleurisy ± pleural effusion Meningism web, mononuclear
2. Pneumothorax – due to rupture of cavity into pleural space Altered mental state cells, cell count 10-
3. Empyema / Pyopneomothorax – rupture of tuberculous lesion into pleural Vomiting 1000, ↓glucose, N/↑
space Neurological deficits protein
4. Fungal colonization of cavities – eg aspergilloma formation 5. LN Usually cervical LN.
5. Respiratory failure & right heart failure – late stage cx due to extensive Swelling and sinus formation
pulmonary destruction and fibrosis 6. Bone / Joint Vertebral collapse X-ray
6. TB laryngitis Pyarthrosis MRI to determine
7. TB enteritis – swallowing of infected sputum. Osteomyelitis extent of involvement
8. Ischiorectal abscess Cold abscess formation Culture biopsies
9. Miliary TB Bone marrow: anaemia,
thrombocytopenia
Transmission & Infectious Period 7. Others Adrenal gland destruction → Addison’s
Airborne. disease
Smear + pul TB considered non-infectious after 2 wks of effective Rx Skin: lupus vulgaris, erythema nodosum
Smear negative and non-pul TB is generally not infectious. Eyes: Phlyctenular keratoconjunctivitis,
iritis, choroiditis
Clinical features
1) Pulmonary TB Other pertinent history:
Symptoms Contact history with anyone with similar symptoms
Fever Pleural pain Lethargy Comorbidities predisposing to TB – DM/ CRF/ HIV/ Steroids
Persistent cough Spontaneous pneumothorax LOW Previous TB
Hemoptysis Non-resolving pneumonia Night sweats

2. Investigations Continuation phase Rifampicin & As above
Microbiology Samples: sputum, induced sputum (using nebuliser), laryngeal swab and (4 mths on 2 drugs Isoniazid
direct smear, NG aspirate (pump in saline and withdraw in the morning), Ethambutol 15mg/kg/day PO For resistant TB
BAL, pleural fluid, pleura, urine, pus, ascites, CSF
ZN or auramine stain Common & Important ADRs
o + in 30% (up to 70%) Rifampicin Hepatitis Stop if bilirubin rises
o Indicates high bacterial population and infectiousness. Cholestasis
o Not specific for MTB. May be other mycobacterial spp. Orange discoloration of urine & tears
C/S Severe thrombocytopenia
o + in 66% Visual changes
o Specific for MTB Liver enzyme inducer Caution in concurrent use with
o Average 12-14 days for + result to return, another 1-2wks for OCP, warfarin, steroids, OHGA,
sensitivity results phenytoin & digoxin.
o Culture usually kept for up to 8 wks if negative Isoniazid Hepatitis
Radiology CXR: Neuropathy, encephalopathy Give pyridoxine (Vit B6) to prevent
o consolidation, cavitations, fibrosis, calcification / tuberculoma, collapse Pyridoxine deficit
o Post TB bronchiectasis (usu upper lobes) Agranulocytosis
o reticular-nodular opacities in miliary TB Pyrazinamide Hepatitis
Mantoux Tests skin sensitivity to tuberculoprotein. + = sensitivity, NOT active infxn Arthralgia, gout Contraindicated in gout
test (only 20% of infected individuals devt active infxn). May be + during Ethambutol Optic neuritis Test color vision before initiating Rx
dormant OR active infection. Gout
Inject 0.1ml of PPD intradermally Streptomycin Vestibular disturbance / ototoxicity Test for hearing before initiating Rx
Read at 2-4 days: + if induration >10mm (locally 15mm), − if <5mm Nephrotoxicity
False −: in sarcoidosis, malnutrition, Hodgkin’s dz, immunosuppression and
overwhelming active TB Second line drugs:
False +: atypical mycobacterial infections o Aminosalicylic acid
Main use for contact tracing, to treat for latent TB infection o Cycloserine
Serology o Ethionamide
γ-interferon Eg Quantiferron, Elispot o Ofloxacin / Ciprofloxacin
assays More sensitive c.f Mantoux test, but expensive. Not routinely done yet. Meningeal, ureteric and pericardial disease: consider adding steroids to reduce risks of Cx
from scarring
Monitoring of Rx efficacy – AFB smear & culture @ 2mths of Rx and after completing Rx,
Management plus CXR after completing Rx.
1) Isolation
For infectious pulmonary TB PTs. 3) Consider HIV testing
Stop isolation only after >2 sputum cultures are AFB negative esp if high-risk group, or young (who don’t usually get TB. ?HIV)
2) Chemotherapy 4) Contact tracing & notification
Check liver and renal functions, as well as color vision due to ethambutol ocular toxicity. Household contacts of sputum-smear positive PTs
Give Pyridoxine throughout treatment to prevent isoniazid induced neuropathy 2/3-step contact tracing
Directly Observed Therapy (DOT) to ensure compliance – daily Rx at TB control unit (CDC) o week 0 – do Mantoux, read at day 2-4
and polyclinics. Alternative: Intermittent DOT (3x/week). 97% cure rate
♦ if >15mm, means seroconvert – give prophylaxis
♦ if <15mm, repeat Mantoux
Short-course regimen
o week 2 – do Mantoux
Initial phase (8 wks *Rifampicin 600-900mg PO 3X/wk
♦ if increase cf week 0’s test by >10mm, means that first
/2mths on 3-4 drugs) *Isoniazid 15mg/kg PO 3X/wk
Mantoux reactivated previously exposed immune system, now
*Pyrazinamide 2.5g PO 3X/wk pt is displaying competent immune response – don’t need
Monitor LFTs wkly Ethambutol 30mg/kg PO 3X/wk Add ethambutol or prophylaxis
Streptomycin 0.75-1g/day IM streptomycin if ♦ if <10mm, do third Mantoux
resistance is suspected.

3. o week 12 – do Mantoux
♦ if increase >10mm cf week 0, means pt has seroconverted, pt
has LTBI, give prophylaxis
♦ if increase <10mm, no need prophylaxis
5) Chemoprophylaxis
Consider for:
o Severely immunosuppressed PTs (eg HIV +)
o Unvaccinated contacts with recent MT +
Isoniazid 300mg/day PO for 9 mth/ rifampicin 4 months if Mantoux positive as described
6) BCG vaccination at birth.
Only protects against childhood miliary and CNS TB.
Repeat vaccination in adolescence not found to affect outcome / risk of TB, and is no
longer indicated.
7) Rx of Latent TB Infection
Preventive ChemoRx
Isoniazid (6mths locally, 9mths in USA) – effective in eradicating latent TB in 70%.
Resistance to isoniazid not known to occur in the remainding 30% despite monotherapy.
Digitally signed by DR WANA HLA SHWE
DN: cn=DR WANA HLA SHWE, c=MY, o=UCSI
University, School of Medicine, KT-Campus,
Terengganu, ou=Internal Medicine Group,
email=wunna.hlashwe@gmail.com
Reason: This document is for UCSI year 4 students.
Date: 2009.02.24 14:06:33 +08'00'