Eosinophilic bronchitis was first defined as a clinical diagnosis in 1989, associated with inhalation of allergens or occupational exposure to chemical agents or products. The primary clinical manifestation is chronic cough (lasting more than 8 weeks), typically dry or with minimal white sticky sputum production, with varying duration and no other significant symptoms or signs. Chest X-rays appear normal, pulmonary function tests show normal ventilation, and airway hyperresponsiveness is negative. Sputum cytology reveals eosinophil proportion ≥2.5%. Other eosinophilic diseases must be excluded. The condition responds well to oral or inhaled corticosteroids, while bronchodilators are generally ineffective. Eosinophilic bronchitis needs to be differentiated from various diseases presenting with chronic cough, such as cough-variant asthma, COPD, chronic bronchitis, and gastroesophageal reflux disease.