Are eosinophils elevated in vaping-induced lung injury?

Eosinophils in Vaping-Induced Lung Injury

Yes, eosinophils can be elevated in vaping-induced lung injury, with several case reports documenting acute eosinophilic pneumonia as a manifestation of EVALI. While not the most common presentation, eosinophilic inflammation represents an important subset of vaping-related lung pathology.

Eosinophilic Patterns in EVALI

• Acute eosinophilic pneumonia (AEP) is a rare but documented manifestation of vaping-induced lung injury, characterized by increased eosinophil levels in bronchoalveolar lavage (BAL) fluid 1, 2
• Case reports have shown BAL fluid with markedly elevated eosinophil counts (up to 64%) in patients with vaping-related lung injury 2
• This pattern suggests an acute hypersensitivity reaction to inhaled antigens from vaping products 3

Clinical Presentation and Diagnosis

• Patients with eosinophilic EVALI typically present with:

  • Acute respiratory symptoms including fever, cough, and respiratory distress 1, 2
  • Bilateral pulmonary infiltrates on imaging 1, 3
  • Peripheral eosinophilia that may develop gradually 4
  • Negative infectious workup 1, 2

• Diagnostic evaluation should include:

  • Chest imaging (CXR and consider CT scan even if CXR is normal) 5
  • Bronchoalveolar lavage to assess for eosinophilia when clinically indicated 1, 2
  • Ruling out other possible etiologies such as infection 5

Management Considerations

• Discontinuation of all e-cigarette and vaping products is essential 5
• Systemic corticosteroids have shown benefit in cases of eosinophilic EVALI 5, 4
• Patients with oxygen saturation <95% on room air, respiratory distress, or significant comorbidities should be hospitalized 5
• Empiric antimicrobial therapy should be considered until infection is ruled out 5

Associated Factors and Variations

• Both nicotine-containing and nicotine-free vaping products have been implicated in eosinophilic lung injury 1, 2
• Tetrahydrocannabinol (THC) oil, especially from unregulated sources, has been associated with eosinophilic pneumonia 3, 6
• Dilutants in vaping products (propylene glycol, vitamin E, flavoring ingredients) may contribute to adverse respiratory effects 6

Follow-up Recommendations

• Initial outpatient follow-up should occur within 48 hours of discharge 5
• Pulmonology follow-up should be arranged within 2-4 weeks 5
• Patients who received corticosteroids should be monitored for potential adrenal insufficiency 5

Important Caveats

• Eosinophilic patterns may not be uniformly distributed throughout the lungs, with reports of discordant bilateral BAL findings 6
• While eosinophilic pneumonia is documented in EVALI, it is not the predominant pattern in most reported cases 6
• Patients with cardiac disease, chronic pulmonary disease, diabetes, and older age have higher risk for rehospitalization and death from EVALI 5