In the past few years, ever since EVALI was identified as a specifical condition, many have been the efforts to define diagnostic criteria, its pathogenesis, and predisposing factors.

Looking at the 2800 cases reported to the CDC [9], approximately 66 percent of patients were male, and nearly 80 percent were under 35 years old (range 13 to 85 years) [9]. Furthermore, 22 percent of patients had underlying asthma [12] and so did our patient. Diagnostic criteria haven't been agreed upon yet and EVALI still remains a diagnosis of exclusion. The CDC, as well as the New York State Department of Health, in conjunction with the University of Rochester Medical Center have proposed a diagnostic algorithm which includes an evocative history of E_cigarette use in the last 90 days, a compatible clinical presentation with respiratory, gastrointestinal or systemic symptoms and suggestive radiological findings [11].

Specifically, EVALI should be suspected in a patient with a history of vaping presenting with respiratory symptoms such as shortness of breath, cough, chest pain, pleuritic chest pain and haemoptysis and/or gastrointestinal symptoms such as nausea, vomiting, diarrhoea and abdominal pain. Systemic symptoms such as fever, tachycardia and tachypnoea may be present. Hypoxemia may be present and progression to respiratory failure is common [12]. Bloodwork doesn’t show specifical evidences, nevertheless, some elements may be evocative of EVALI: a non-specific raise of the inflammation indexes may be detected. Blood exams may also be useful to exclude other processes in the differential diagnosis [13, 14]. The radiological evaluation in patients with suspected EVALI generally shows diffuse hazy or consolidative opacities at the chest radiograph. Chest CT would typically show a ground glass imaging with spare of the sub pleural space [15]. GGOs (Ground-glass opacification) are common, and the most useful imaging features to help differentiate EVALI from COVID-19 are subpleural sparing of pulmonary opacities (GGOs) and centrilobular nodules (infrequent in COVID-19) (Fig. 2). In our case there was no thickening of the interlobular septa, but the reversed halo sign was present (atoll sign) (Fig. 3), which is characterized by the presence of a central ground-glass opacity surrounded by dense consolidation of crescentic shape or complete ring (sign present in late phase COVID-19 and typical of BOOP (bronchiolitis obliterans organizing pneumonia) and Wegener). These findings are consistent with diffuse alveolar damage, as seen in acute respiratory distress syndrome. The radiological findings vary according to the underlying histopathological process. Histology isn’t routinely performed, several pathologic patterns of lung injury have been reported in the setting of vaping such as lipoid pneumonia, diffuse alveolar damage, acute eosinophilic pneumonia, organizing pneumonia, diffuse alveolar haemorrhage, respiratory bronchiolitis interstitial lung disease, hypersensitivity pneumonitis and giant cell interstitial pneumonia, prompting the heterogeneity of the underlying disease processes. [16–21]. At the broncho alveolar lavage fluid (BAL) of affected patients the most commonly found substances appeared to be tetrahydrocannabinol (THC) and/or vitamin E acetate, the presence of lipid-laden macrophages seen with oil red O staining has been reported as well [22, 23]. Vitamin E had been recently looked at as possible culprit in the pathogenesis of EVALI as multiple studies report its presence in the BAL samples from patients affected from EVALI, while it hasn't been detected in healthy individuals [9, 23]. Vitamin E is often used as a thickening agent of illegal THC containing vapes. According to the American public health authorities, in order to formalise the diagnosis of EVALI, vaping should be present within 90 days prior to the symptom onset, an underlying infectious cause needs to be ruled out and there should be no evidence of other plausible diagnoses (e.g. cardiac, rheumatologic or neoplastic processes) [9, 24].

The microbiological work-up for our patient didn’t show any significant microbiological evidence explaining the radiological findings. Rhinovirus wasn’t considered to be consistent with the radiological case. There have been a few cases of acute respiratory failure due to Rhinovirus reported in literature with several radiological findings, but these were mainly in patients with comorbilities, while there are only isolated case report in immunocompetent hosts [18]. Furthermore, her familiar and personal history wasn’t consistent with any rheumatologic or specifical clinical entities to investigate. She quickly responded to therapy and more invasive exams, such as BAL, were ruled out for this case.

As we assumed that the history of multiple allergies and asthma played a role in determining the respiratory failure, we decided to investigate that possibility and the patient showed an asthmatic condition at the tests and was therefore put on preventive therapy.

Due to the personal history of CBD use and the important clinical presentation, we decided to also rule out drug use.

The first step in the treatment approach would be the cessation of vaping [24].

Antibiotic coverage is needed until an underlying infectious process is excluded.

EVALI uses improves over a course of systemic corticosteroids [25]. Oxygen support may be needed in case of worsening hypoxia or dyspnoea through an appropriate interface (nasal cannula or face masks) [26].

E-cigarettes are a relatively new device. Even though there have been many attempts to fully understand the health impact of vaping on E-cigarette users, further studies and on a longer observation time will be needed to define its actual impact on health and future long-term implications.