Is there an association between vaping and eosinophilia (elevated eosinophil count)?

From the Guidelines

Vaping has been associated with eosinophilia, and if you're experiencing eosinophilia and use vaping products, I strongly recommend discontinuing vaping immediately as this may be the primary cause of your condition. The chemicals in vaping products, particularly propylene glycol, vegetable glycerin, flavorings, and nicotine, can trigger inflammatory responses in the lungs and throughout the body. This inflammation can lead to increased eosinophil production as your immune system responds to what it perceives as harmful substances. Cases of vaping-associated lung injury (EVALI) have shown eosinophilic pneumonia as one potential manifestation.

Key Points to Consider

• Eosinophilia is characterized by elevated levels of eosinophils in the blood or tissues, which can be triggered by various factors including allergic reactions and exposure to harmful substances.
• Vaping products contain chemicals that can cause inflammation in the lungs and body, potentially leading to eosinophilia.
• If you're experiencing symptoms such as cough, shortness of breath, chest pain, or fever alongside eosinophilia, seek medical attention promptly.
• Treatment typically involves cessation of vaping, supportive care, and in some cases, corticosteroids like prednisone to reduce inflammation, as supported by studies such as 1.
• Your healthcare provider may also recommend bronchodilators for breathing difficulties, and recovery time varies depending on exposure duration and severity but typically improves within weeks after vaping cessation.

Underlying Mechanism

The underlying mechanism involves direct chemical irritation to lung tissue and immune system activation, with eosinophils being recruited as part of this inflammatory response. This is consistent with findings from studies on asthma and non-asthmatic eosinophilic bronchitis, which highlight the role of eosinophils in inflammatory responses, as discussed in 1 and 1.

Importance of Discontinuing Vaping

Given the potential link between vaping and eosinophilia, discontinuing vaping is crucial for managing and potentially resolving eosinophilia. This recommendation is based on the principle of removing the potential cause of inflammation and allowing the body to recover, as emphasized in guidelines for managing conditions associated with eosinophilia, such as those discussed in 1 and 1.

From the Research

Eosinophilia and Vaping Association

There is no direct evidence in the provided studies to suggest an association between vaping and eosinophilia (elevated eosinophil count) [ 2, 3, 4, 5, 6 ].

Definition and Diagnosis of Eosinophilia

• Eosinophilia is defined as a peripheral blood eosinophil count greater than 1500/mm3 or 1.5 × 109 /L [ 4, 5 ].
• Diagnosis of primary eosinophilias relies on a combination of morphologic review of the blood and marrow, standard cytogenetics, fluorescence in situ-hybridization, flow immunophenotyping, and T-cell clonality assessment [ 4, 5 ].

Treatment and Management of Eosinophilia

• The goal of therapy is to mitigate eosinophil-mediated organ damage [ 4, 5 ].
• Corticosteroids are first-line therapy for patients with lymphocyte-variant hypereosinophilia and HES [ 4, 5 ].
• Hydroxyurea and interferon-alpha have demonstrated efficacy as initial treatment and in steroid-refractory cases of HES [ 4, 5 ].

Specific Conditions and Eosinophilia

• Acute eosinophilic pneumonia (AEP) patients with initial eosinophilia may have a milder disease than those with an initial normal peripheral eosinophil count (PEC) [ 6 ].
• Rapid corticosteroid tapering may be an acceptable treatment strategy for managing AEP patients with initial eosinophilia [ 6 ].