Tuberculosis

Today we discussed issues related to tuberculosis

Risk factors for initial infection:

1) Native of country with high prevalence

2) Homelessness

3) History of incarceration

4) Aboriginal origin

5) Household exposure to case of active TB

6) Healthcare worker

Risk factors for reactivation:

1) HIV

2) TNF antagonist therapy

3) Head and neck malignancy

4) DM2

5) ESRD

6) Silicosis

7) Chemotherapy

8) Prednisone > 15mg x > 2 weeks

Some of the many possible presentations:

Pulmonary: constitutional symptoms, chronic cough, hemoptysis, apical, posterior upper, or superior lower lobe opacity

Miliary- widespread dissemination to lungs, spleen, liver, marrow, nodes, adrenals

Lymphadenitis- "scrofula" when neck nodes burst

Adrenal insufficiency (#1 cause worldwide)

Osteomyelitis (Pott's disease)

Genitourinary

Pericardial effusion

Large joint arthritis

Meningitis

Abdominal- terminal ileal disease, malabsorption, peritonitis

Therapy: Direct observed therapy (DOT) is optimal

4 drugs for 2 months, 2 drugs for 4 months

Initially INH, rifampin, pyrazinamide, ethambutol. Narrow by sensitivity result

A few TB eponyms

Gohn's complex- primary pulmonary lesion and associated adenopathy on CXR
Gibbus deformity- vertebral collapse from Pott's disease
Rasmussen's aneurysm- pulmonary artery aneurysm from TB

Some references

Click here for NEJM review on latent TB infection
For the connaisseur, click here for IDSA treatment guidelines
Click here for CMAJ review of extrapulmonary TB