E-cigarette or Vaping Product Use-Associated Lung Injury (EVALI)

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.

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.

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.

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.

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.

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.