[3] Symptoms can initially mimic common pulmonary diagnoses, such as pneumonia, but sufferers typically do not respond to antibiotic therapy.

[17][18][19] According to a systematic review article, "Initial case reports of vaping-related lung injury date back to 2012, but the ongoing outbreak of EVALI began in the summer of 2019.

[24] In late February 2020, a CDC-authored article in the NEJM stated that the VAPI outbreak was "driven by the use of THC-containing products from informal and illicit sources.

"[26] In 2021, researchers at Johns Hopkins University analyzed the vape aerosols of popular brands such as Juul and Vuse, and found "nearly 2,000 chemicals, the vast majority of which are unidentified.

"[27] Due to the COVID-19 pandemic, that exceeded 1 million worldwide deaths in October 2020, it is now possible that shared vaping devices spread COVID-19.

[28] Several organizations, including Purdue University and Public Health England (PHE), strongly advise against sharing vapes.

[3][32] Commonly reported symptoms include shortness of breath, cough, fatigue, body aches, dizziness, fever, nausea, vomiting, and diarrhea.

[4] At the time of hospital presentation, the individual is often hypoxic and meets systemic inflammatory response syndrome (SIRS) criteria, including fever.

[50] Tobacco-specific impurities such as cotinine, nicotine-N'-oxides (cis and trans isomers), and beta-nornicotyrine are believed to be the result of bacterial action or oxidation during the extracting of nicotine from tobacco.

[2] Healthcare providers were advised to evaluate for alternative diagnoses (e.g., cardiac, gastrointestinal, rheumatologic, neoplastic, environmental, or occupational exposures, or causes of acute respiratory distress syndrome) as suggested by clinical presentation and medical history, while also considering multiple etiologies, including the possibility of VAPI occurring with a concomitant infection.

[2] It was pointed out that consulting with specialists (e.g. critical care, pulmonology, medical toxicology, or infectious disease) could help guide further evaluation.

[4] Many of the reported cases involved worsening respiratory failure within 48 hours of admission, following the administration of empiric antibiotic therapy.

[55] There are non-specific laboratory abnormalities that have been reported in association with the disease, including elevations in white blood cell count (with neutrophilic predominance and absence of eosinophilia), transaminases, procalcitonin, and inflammatory markers.

[4] As of September 2019, distinctions were still being made between processes occurring in association with vaping or the use of nicotine-containing liquids and those considered as alternative diagnoses to VAPI.

the CDC recommends that patients with suspected VAPI should be admitted if they have decreased O2 saturation (<95%) on room air, are in respiratory distress, or have comorbidities that compromise pulmonary reserve.

[2] CDC says patients should be advised to discontinue the use of vaping products upon hospital admission and during outpatient follow-up, to speed recovery and avoid potential recurrence of symptoms or lung injury.

[2] Evidence-based tobacco product quitting strategies include behavioral counseling and U.S. Food and Drug Administration (US FDA)-approved cessation medications.

[2] In patients with persistent hypoxemia (O2 saturation <95%) requiring home oxygen at discharge, consider ongoing pulmonary follow-up.

[2] As it is unknown whether patients with a history of VAPI are at increased risk for severe complications with influenza or other respiratory infections, follow-up care should also include annual vaccination against influenza for all persons over 6 months of age, including patients with a history of VAPI, as well as administration of the pneumococcal vaccine according to current guidelines.

[2] An important part of both inpatient and follow-up care for VAPI involves advising patients to discontinue use of e-cigarette or vaping products.

[68] In addition, CDC recommends that individuals not modify or add any substances to e-cigarettes or other vaping products that are not intended by the manufacturer.

[76] As of February 4, 2020[update], there have been 2,758 cases of VAPI[a] reported from all 50 states, the District of Columbia, Puerto Rico, and the US Virgin Islands.

[78] In September 2019, a US Insurance Journal article stated that at least 15 incidents of vaping related illnesses have been reported worldwide prior to 2019, occurring from Guam to Japan to the UK to the US.

[80] 18-year-old Raphaël Pauwaert from Brussels died on November 6, 2019,[82] after developing pneumonia[83] and being placed in a medically induced coma because he was unable to breathe on his own.