"How to Deal with a Persistent Cough: Could Air Conditioning or Fabric Softener Scents Be Triggers? The Emerging Focus on 'Cough Hypersensitivity'"

"Even without a cold or pollen, once I start coughing due to smells or cold air, it doesn't stop." More people are experiencing this. The underlying concept is a new one called "cough hypersensitivity syndrome (CHS)." This is characterized by an increased sensitivity of the airway's "cough reflex," where even mild stimuli that traditionally wouldn't cause coughing, such as air conditioning, dryness, perfumes, fabric softeners, tobacco smoke, conversation, or laughter, can lead to persistent coughing. The Japanese cough guidelines, set to be revised in 2025, and the European Respiratory Society (ERS) are recognizing this as a "treatable trait" of chronic cough, emphasizing the importance of evaluation and treatment. Treatment involves a multi-faceted approach: ① thorough examination and treatment of underlying conditions (such as asthma, eosinophilic airway inflammation, gastroesophageal reflux disease, upper airway cough syndrome), ② behavioral therapy to learn cough control (speech and language therapy: SLT), and ③ combining neuromodulators (like gabapentin) or peripheral antitussives (such as P2X3 receptor antagonists) depending on the case. At home, optimizing the indoor environment (temperature, humidity, airflow), reassessing scented products, maintaining hydration and moisture, avoiding cough triggers, and practicing breathing techniques are effective. If a persistent cough lasts more than 8 weeks, is accompanied by blood in the sputum or difficulty breathing, or if there is ongoing weight loss or fever, it is advisable to consult a specialist promptly.