From the Guidelines
Eosinophilia following hydrochloric acid inhalation requires prompt medical attention and treatment with systemic corticosteroids, typically prednisone 40-60mg daily for 5-7 days with a gradual taper over 2-3 weeks, as recommended by the most recent guidelines 1. This condition occurs when accidental inhalation of hydrochloric acid vapors triggers an inflammatory response in the lungs, causing an increase in eosinophils (a type of white blood cell).
Key Considerations
- In addition to corticosteroids, supportive care includes:
- Supplemental oxygen if oxygen saturation is below 94%
- Bronchodilators such as albuterol (2 puffs every 4-6 hours as needed) for any bronchospasm
- Close monitoring of respiratory function
- The corticosteroids work by suppressing the inflammatory response and reducing eosinophil recruitment to the lungs.
- Patients should be monitored with serial complete blood counts to track eosinophil levels and pulmonary function tests to assess lung recovery.
- Severe cases may require hospitalization, especially if there is evidence of significant respiratory distress or hypoxemia.
- Long-term follow-up is important as some patients may develop reactive airway dysfunction syndrome (RADS) or other chronic respiratory conditions following chemical inhalation injuries, as noted in studies on non-asthmatic eosinophilic bronchitis 1 and asthma 1.
Diagnosis and Management
- Diagnosis relies on the demonstration of significant eosinophilia in sputum samples, usually obtained by sputum induction, as described in the guidelines for occupational eosinophilic bronchitis 1.
- The management regimen includes the avoidance of exposure to the causative work agent and the use of therapy with inhaled steroids.
- Non-invasive measures of airway inflammation, such as sputum cell counts and fractional exhaled nitric oxide (F ENO), can provide additional evidence to support the need for corticosteroid treatment, as recommended in the 2020 CHEST Guideline for managing chronic cough due to asthma and NAEB in adults and adolescents 1.
From the Research
Eosinophilia and Hydrochloric Acid Inhalation
- Eosinophilia is a condition characterized by an elevated count of eosinophils in the blood or tissue, often associated with allergic reactions or asthma 2, 3.
- Hydrochloric acid inhalation can cause respiratory symptoms and lung injury, but its direct effect on eosinophilia is not well-established 4, 5.
Treatment of Eosinophilia
- Prednisone, hydroxyurea, and interferon alpha 2b are effective treatments for controlling eosinophilia and its clinical consequences 2.
- Systemic corticosteroids, such as prednisone, can reduce blood eosinophil counts in patients with asthma 3, 6.
Hydrochloric Acid Inhalation Effects
- Hydrochloric acid inhalation can cause severe symptoms, reduced peak expiratory flow rate, and hypoxaemia, requiring hospital admission in some cases 4.
- A single exposure to hydrochloric acid can lead to chronic lung injury and pulmonary fibrosis, with age-dependent differences in the severity of the injury 5.
Relationship Between Eosinophilia and Hydrochloric Acid Inhalation
- There is limited evidence on the direct relationship between eosinophilia and hydrochloric acid inhalation, but it is possible that the inflammatory response to hydrochloric acid exposure could contribute to eosinophilia in some cases 5.