Difference between revisions of "Tuberculosis"

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==Background==
 
==Background==
 
*>1/3 of world's population is infected
 
*>1/3 of world's population is infected
*Primary Infection
+
*Infection Types
**Usually contained by body via formation of tubercles
+
**Primary Infection
**Hematogenous spread limited to areas w/ high O2 or blood flow (apical lung, vertebrae)
+
***Usually contained by body via formation of tubercles
***PPD positive
+
***Hematogenous spread limited to areas w/ high O2 or blood flow (apical lung, vertebrae)
*Reactivation Infection
+
****PPD positive
**More common in immunocompromised pts (AIDS, malignancy, DM, CRF)
+
**Reactivation Infection
*Check HIV in pts suspected of TB
+
***More common in immunocompromised pts (AIDS, malignancy, DM, CRF)
*Peds
+
**Check HIV in pts suspected of TB
**More likely to progress early to active disease
+
*Special Populations
***Presentation more commonly that of primary TB
+
**AIDS
**>5yr - classic symptoms
+
***TB is 200-500x more common in AIDS population than general population
**<5yr - miliary TB, meningitis, cervical lymphadenitis, PNA that does not respond to abx
+
***CD4 count
**Children are usually not infectious due to their weak cough
+
****Increased risk when <500
 +
****Determines the clinical and radiographic presentations of TB
 +
**Peds
 +
***More likely to progress early to active disease
 +
****Presentation more commonly that of primary TB
 +
***>5yr - classic symptoms
 +
***<5yr - miliary TB, meningitis, cervical lymphadenitis, PNA that doesn't respond to abx
 +
***Children are usually not infectious due to their weak cough
 +
 
 
==Diagnosis==
 
==Diagnosis==
 
===Clinical Features===
 
===Clinical Features===

Revision as of 22:52, 28 November 2011

Background

  • >1/3 of world's population is infected
  • Infection Types
    • Primary Infection
      • Usually contained by body via formation of tubercles
      • Hematogenous spread limited to areas w/ high O2 or blood flow (apical lung, vertebrae)
        • PPD positive
    • Reactivation Infection
      • More common in immunocompromised pts (AIDS, malignancy, DM, CRF)
    • Check HIV in pts suspected of TB
  • Special Populations
    • AIDS
      • TB is 200-500x more common in AIDS population than general population
      • CD4 count
        • Increased risk when <500
        • Determines the clinical and radiographic presentations of TB
    • Peds
      • More likely to progress early to active disease
        • Presentation more commonly that of primary TB
      • >5yr - classic symptoms
      • <5yr - miliary TB, meningitis, cervical lymphadenitis, PNA that doesn't respond to abx
      • Children are usually not infectious due to their weak cough

Diagnosis

Clinical Features

Primary Tuberculosis

  • Usually asymptomatic (only identified by positive PPD)
  • May be rapidly progressive and fatal in immunocompromised pts
    • Fever, malaise, wt loss, chest pain
  • Tuberculous pleural effusion may occur if subpleural node ruptures into the pleura
    • Pleuritic chest pain
    • Exudative fluid
      • Organisms may not be visible on acid-fast staining (need pleural biopsy)

Reactivation Tuberculosis

    • Pulmonary: Productive cough, hemoptysis, dyspnea, pleuritic chest pain
    • Systemic: Fever, night sweats, malaise, fatigue, wt loss
    • Extrapulmonary
      • Lymphadenopathy (painless)
      • Pericarditis
      • Meningitis
      • Adrenal insufficiency
      • Arthritis
      • Osteomyelitis

CXR

  • Primary infection
    • Infiltrates in any area of the lung
    • Isolated hilar or mediastinal adenopathy may be only finding
  • Reactivation infection
    • cavitary/noncavitary lesions in upper lobe or superior segment of lower lobe
  • Latent infection
    • Upper lobe or hilar nodules and fibrotic lesions
    • Ghon foci, areas of scarring, calcification
  • HIV pts less likely to have classic lesions and may have normal CXR

Treatment

Active TB

  • Isoniazid + rifampin + pyrazinamide + ethambutol x8wk followed by INH/RIF x18wk
    • 2 drug continuation tx x 18-31wk

Latent TB

  • Consider treatment for:
    • Recent conversion to PPD-positive
    • Persons in close contact w/ individual w/ active TB
    • Isoniazid x9mo

Disposition

  • Discharge
    • Otherwise healthy
      • Contact public health services before discharge
        • Instructions for home isolation and f/u at appropriate clinic to receive meds
      • Do not start TB meds in ED unless specifically instructed by public health
  • Admit
    • Ill-appearing
    • Diagnosis is uncertain
    • Pt is noncompliant