[TWO CASES OF ASTHMA INDUCED BY SMOKE FROM BURNING RICE STRAWS AND RICE HUSKS]

Area of Science:

• Environmental Health
• Pulmonology
• Toxicology

Background:

• Patients presented with respiratory symptoms like dyspnea, cough, and wheeze.
• Symptoms were exacerbated by seasonal exposure to smoke from burning rice straw and husks, common in Japan.
• Other triggers included incense, lilies, and air fresheners, all containing volatile organic compounds (VOCs).

Purpose of the Study:

• To investigate the link between VOC exposure and asthma development.
• To diagnose and manage asthma triggered by environmental irritants.
• To evaluate treatment efficacy in patients with VOC-induced asthma.

Main Methods:

• Clinical presentation analysis of two patients with respiratory symptoms.
• Pulmonary function tests, including forced expiratory volume in one second (FEV1) and methacholine challenge test.
• Assessment of peripheral eosinophil counts and fractional exhaled nitric oxide (FeNO) levels.
• Evaluation of treatment response to Symbicort (budesonide/formoterol).

Main Results:

• Both patients diagnosed with asthma triggered by VOCs.
• Variable airflow obstruction noted (FEV1 fluctuation >0.6L).
• Airway hyperresponsiveness confirmed in one patient via methacholine challenge.
• No elevated eosinophils or FeNO, ruling out eosinophilic inflammation.
• Symbicort therapy effectively reduced systemic corticosteroid dosage.

Conclusions:

• Volatile organic compounds (VOCs) from environmental sources like burning rice straw can induce asthma.
• Asthma presentation may include variable airflow obstruction and airway hyperresponsiveness.
• Treatment with Symbicort is effective in managing VOC-induced asthma and reducing steroid dependence.