Trimellitic Anhydride


  • Manufacture of Paints/Epxoy Resins/Plastics: commonly occurs following spraying of trimellitic anhydride onto a hot surface -> generates fumes


  • Trimellitic Anhydride Fume or Dry Powder Inhalation
    • Mechanism: probable immunologic reaction for alveolar hemorrhage

Clinical Presentations

  • Occupational Asthma (see Asthma-Occupational, [[Asthma-Occupational]])
  • Diffuse Alveolar Hemorrhage (see Diffuse Alveolar Hemorrhage, [[Diffuse Alveolar Hemorrhage]])
    • Epidemiology
      • Latency Period: 1-3 months after exposure
    • Diagnosis
      • CXR/Chest CT Patterns: diffuse or patchy focal alveolar infiltrates
        • Interstitial infiltrates may appear with chronic or recurrent disease
      • Anitbodies to trimellitic anhydride: may be present
      • CBC: leukocytosis, anemia (iron deficiency if bleeding is severe or recurrent)
      • ESR: elevated
      • Urinalysis: usually normal
      • PFT’s: increased DLCO (during alveolar hemorrhage)
      • OLB: absence of Pulmonary Capillaritis: bland alveolar hemorrhage
    • Clinical
      • Cough
      • Dyspnea
      • Hemoptysis: may be absent on initial presentation in some cases (even after significant bleed)
      • Chest Pain: may occur
      • Absence of renal or other systemic involvement
  • Interstitial Lung Disease (see ILD-Etiology, [[ILD-Etiology]]): may occur with recurrent diffuse alveolar hemorrhage


  • Avoid Exposure: symptoms usually resolve without sequelae


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