Effect of peppermint oil steam inhalation on pulmonary function in patients with bronchial asthma: a case series

Asthma is a chronic inflammatory disorder characterized by airway inflammation, airflow restriction, and bronchial hyperresponsiveness. Conventional treatments for asthma, though effective, often come with side effects, creating a demand for complementary therapies. Peppermint oil, known for its anti-inflammatory and bronchodilatory properties, has not been previously studied for its effects on asthma patients. This study explores impact of peppermint oil steam inhalation on pulmonary function in patients with bronchial asthma. This case series included three asthma patients (ages 19-24 years) with varying severity of asthma. Each participant received daily steam inhalation with peppermint oil for 7 days using a facial sauna. Pulmonary function tests (PFT) were conducted using spirometry to measure forced vital capacity (FVC), forced expiratory volume in first second (FEV1), FEV1/FVC ratio, peak expiratory flow rate (PEFR), and forced expiratory flow (FEF 25-75%) before and after intervention. Peppermint oil steam inhalation improved pulmonary function in all cases: Case 1: FVC increased from 92-105%, FEV1 from 91-105%, and PEFR from 86-109%. Case 2: FVC increased from 97-102%, FEV1 from 87-95%, and PEFR from 89-92%. Case 3: FVC increased from 90-94%, FEV1 from 78-84%, and PEFR from 74-79%. This case series suggests that peppermint oil steam inhalation can improve pulmonary function in asthma patients, offering a potential complementary therapy. Larger studies with extended follow-up are needed to validate these findings.