An had undergone multiple courses of antibiotics for respiratory inflammation and previously had adenoidectomy and turbinate cauterization. Her persistent cough worsened at night and during seasonal changes, often leading to vomiting. She also experienced nasal itching, sneezing, and a clear runny nose.

Associate Professor, Doctor Hoang Thi Lam, Head of the Clinical Immunology Department at Tam Anh General Hospital TP HCM, noted An's history of atopic dermatitis since childhood and her father's chronic allergic rhinitis. Suspecting an allergic cause for her cough, Associate Professor Lam ordered specialized allergy tests and comprehensive respiratory function assessments. Results showed the child was positive for house dust mites, specifically Dermatophagoides pteronyssinus and Blomia tropicalis. Her specific IgE levels were elevated, and the bronchial provocation test was positive.

Associate Professor Lam diagnosed An with cough-variant asthma accompanied by allergic rhinitis, where the cough was the most prominent and persistent symptom.

Associate Professor Lam explains An's condition to her mother. Photo: Tam Anh General Hospital

According to Associate Professor Lam, prolonged cough in children has many causes, most commonly viral or bacterial respiratory infections. Children with recurrent coughs are often diagnosed as having respiratory infections. However, An's case, characterized by no fever, no obvious wheezing, and a cough primarily at night, suggested airway allergy, particularly cough-variant asthma, which is frequently overlooked or misdiagnosed.

When individuals with cough-variant asthma and allergic rhinitis are exposed to allergens like house dust mites or pollen, their immune system overreacts, causing airway inflammation that manifests as a prolonged cough. Therefore, treating these conditions as infections with antibiotics or surgery is ineffective, providing only temporary symptom relief. The underlying inflammation persists, leading to extended, recurrent coughs and even acute attacks requiring hospitalization.

After two weeks of appropriate treatment, combined with environmental control measures to reduce allergens, An's cough lessened, and she slept better. Associate Professor Lam advised the family to regularly change bed sheets, limit stuffed animals, avoid keeping pets in the bedroom, and use an air purifier to reduce the risk of asthma and allergic rhinitis recurrence for the child.

Associate Professor Lam emphasized that a cough lasting more than a few weeks, especially if it occurs at night, is seasonal, or is accompanied by allergy symptoms such as nasal itching, sneezing, or a clear runny nose, warrants evaluation for airway allergies. A correct diagnosis ensures appropriate treatment, preventing prolonged coughs and limiting the risk of hospitalization due to acute episodes.

Minh Huong

*Character's name has been changed