Difference between revisions of "Tuberculosis"

(Primary Tuberculosis)
(Diagnosis)
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**Looks like millet seeds on CXR
 
**Looks like millet seeds on CXR
 
[[File:Miliary.png|thumbnail|CXR of miliary TB]]
 
[[File:Miliary.png|thumbnail|CXR of miliary TB]]
*HIV pts less likely to have classic lesions and may have normal CXR
+
*Immunocompromised patients less likely to have classic lesions and may have normal CXR
 
===Tuberculin Skin Test===
 
===Tuberculin Skin Test===
 
*Reaction considered positive in following situations
 
*Reaction considered positive in following situations

Revision as of 22:16, 12 July 2016

Background

Miliary TB neonate born to mother with active TB
  • Over 1/3 of world's population is infected
    Bilateral pulmonary tuberculosis

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 patients (AIDS, malignancy, DM, immunosupressive medications)
  • Miliary Tuberculosis
    • Disseminated tuberculosis
    • Looks like millet seeds
    • Seen in patients with comorbid AIDS
      • Check HIV in patients suspected of TB
    • PPD is positive in only 50% of cases

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
  • Pediatric
    • More likely to progress early to active disease
      • Presentation more commonly that of primary TB
    • >5yr - classic symptoms
    • <5yr - milliary TB, meningitis, cervical lymphadenitis, pneumonia that doesn't respond to usual antibiotics
    • Children are usually not infectious due to their weak cough

Clinical Features

Primary Tuberculosis

  • Usually asymptomatic (only identified by positive PPD/quantiferon gold)
    Tuberculous lymphadenopathy
    Tuberculous vertebral osteomyelitis (Pott's Disease)
  • May be rapidly progressive and fatal in immunocompromised pts
    • Fever, malaise, weight 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
    • Painless lymphadenopathy/scrofula (most common extrapulmonary manifestation)
    • Pericarditis
    • Peritonitis
    • Meningitis
    • Adrenal insufficiency
      • Think about in the patient presenting in shock with TB risk factors
    • Arthritis
    • Osteomyelitis
      • Pott's disease, usually in thoracic spione

Differential Diagnosis

HIV associated conditions

Diagnosis

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
  • Miliary TB
    • Looks like millet seeds on CXR
CXR of miliary TB
  • Immunocompromised patients less likely to have classic lesions and may have normal CXR

Tuberculin Skin Test

  • Reaction considered positive in following situations
    • >5 mm
      • HIV positive
      • Close contact with active TB patient
      • Nodular or fibrotic changes on CXR
      • Immunosuppressed (TNF-alpha inhibitor, chemo, organ transplant)
    • >10 mm
      • Children < 4 yrs old
      • Healthcare/lab/prison employees and residents
      • Co-morbid conditions (dialysis, DM, blood/head/neck/lung malignancy, IV drug users)
      • People from high prevalence areas
    • >15 mm
      • Persons with no known risk factors for TB

Management

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
  • Patient is noncompliant

References

  1. Gutteridge, David L MD, MPH, Egan, Daniel J. MD. The HIV-Infected Adult Patient in The Emergency Department: The Changing Landscape of the Disease. Emergency Medicine Practice: An Evidence-Based Approach to Emergency Medicine. Vol 18, Num 2. Feb 2016.