Introduction and Epidemiology
- EVALI is an acute or subacute, severe respiratory illness characterized by clinicopathologic findings that mimic infectious pulmonary diseases.
- The illness disproportionately affects pediatric, adolescent, and young adult populations.
- The vaping industry aggressively targets youth utilizing thousands of fruit and candy-flavored liquids and highly concentrated nicotine salts.
Toxicological Profile and Etiopathogenesis
| Toxic Agent | Pathophysiological Mechanism |
|---|---|
| Vitamin E Acetate | Primary implicated toxic agent; thermal decomposition within the vape pen produces ketene gas, a highly reactive and severe pulmonary irritant. |
| Aldehydes and VOCs | Aerosolized propylene glycol and vegetable glycerin generate carcinogenic aldehydes, specifically formaldehyde and acrolein. |
| Heavy Metals | Degradation of metallic heating coils leaches aerosolized nickel, tin, lead, and chromium deep into the terminal bronchioles. |
| Nicotine Salts | Lower pH formulation eliminates the harsh throat hit, allowing adolescents to deeply inhale massive, concentrated doses, driving rapid neurological addiction. |
Clinical Presentation and Pathophysiology
- Pathophysiology: Involves direct thermal and chemical damage to the alveolar epithelium, provoking a massive, unregulated immune-mediated inflammatory response.
- Histological Patterns: Includes exogenous lipoid pneumonia (lipid-laden macrophages), acute fibrinous and organizing pneumonia (AFOP), diffuse alveolar damage (DAD), and diffuse alveolar hemorrhage (DAH).
- Gastrointestinal Symptoms (75-85%): Severe nausea, vomiting, secretory diarrhea, and diffuse abdominal pain frequently precede the onset of respiratory distress by several days.
- Respiratory Symptoms (85-95%): Progressive dyspnea, dry non-productive cough, pleuritic chest pain, and hypoxia that can rapidly deteriorate into fulminant respiratory failure.
- Systemic Symptoms: High-grade fever, chills, tachycardia, profound fatigue, and unintended weight loss mimic severe viral sepsis.
Diagnostic Criteria and Radiology
- EVALI remains a strict diagnosis of exclusion.
- CDC Diagnostic Criteria: Requires a history of e-cigarette use within 90 days prior to symptom onset, pulmonary infiltrates or ground-glass opacities on imaging, absence of pulmonary infection, and no alternative plausible diagnosis.
- Radiological Signature: High-Resolution Computed Tomography (HRCT) consistently reveals bilateral, dependent, basilar-predominant ground-glass opacities.
- Subpleural Sparing: A highly characteristic radiologic sign (a thin rim of unaffected normal lung tissue adjacent to the pleura) that helps differentiate EVALI from typical viral pneumonias like COVID-19.
Management Protocols (AAP/CDC 2025-2026)
- Triage Criteria: Outpatient management is strictly reserved for patients with normal oxygen saturation ($\ge$95% on room air), absolute absence of respiratory distress, reliable healthcare access, and guaranteed 24-48 hour follow-up.
- Empiric Antimicrobial Therapy: Immediate initiation of empiric antibiotics targeting community-acquired pneumonia and empiric antivirals is mandatory, discontinued only after extensive microbiological and viral panels return definitively negative.
- Systemic Corticosteroids: The cornerstone of definitive pharmacological therapy. Inpatients receive intravenous methylprednisolone (1 to 2 mg/kg/day), yielding rapid clinical and radiographic improvement, followed by an oral prednisone taper over 1 to 2 weeks to prevent rebound inflammation.
Indian Context and Prevention
- The PECA Act (2019): India enacted legislation completely banning the production, import, and sale of e-cigarettes; however, pediatricians must remain vigilant as an unregulated black market continues to supply illicit, contaminated vaping products to adolescents.
- Screening: Standard pediatric practice mandates confidential screening using the updated HEADSSS assessment, specifically assessing for screens and social media along with substance use.
- Immunization Mandates: Children with a history of EVALI are at a profoundly elevated risk for life-threatening secondary respiratory infections; timely annual vaccination against seasonal influenza, COVID-19, and pneumococcal disease is strictly mandated.