Immunology Asthma Diagnosis and Differential Diagnosis in Children

Asthma Diagnosis and Differential Diagnosis in Children Mohammad Gharagozlou, MD Division of Allergy & Immunology, Children's Medical Center, Tehran University of Medical Sciences Asthma is a chronic inflammatory disorder of the airways characterized by variable respiratory symptoms and reversible airflow limitation. In children, diagnosis can be challenging due to age-related limitations in objective testing and the overlap with other respiratory disorders. Diagnosis The diagnosis of asthma in children is based on a combination of clinical history, physical examination, and supportive investigations. Key features include: • Recurrent symptoms: episodes of wheeze, cough, breathlessness, or chest tightness, often worse at night or in the early morning. ⚫ Triggers: symptoms precipitated by exercise, allergen exposure, viral infections, or cold air. Variability and reversibility: spontaneous improvement or response to bronchodilator or anti-inflammatory therapy. Family and personal atopy history: allergic rhinitis, eczema, or family history of asthma. In children ≥۵ years, spirometry demonstrating reversible airflow obstruction supports the diagnosis. In preschool children, objective confirmation is often not feasible; diagnosis relies on symptom patterns and therapeutic trials with inhaled corticosteroids. Differential Diagnosis Several conditions may mimic asthma in children and should be considered, particularly when features are atypical or response to treatment is poor: • Viral-induced wheeze: common in preschool children; wheeze occurs only with infections and may resolve with age. Bronchiolitis: acute viral lower respiratory tract infection in infants, typically ۱۲ months. • Foreign body aspiration: sudden onset cough, localized wheeze, or asymmetric breath sounds. • Structural airway anomalies: laryngomalacia, tracheomalacia, or bronchomalacia causing persistent noisy breathing. Cystic fibrosis: chronic cough, failure to thrive, recurrent infections; confirmed by sweat chloride test or genetic testing. Primary ciliary dyskinesia: neonatal respiratory distress, chronic productive cough, situs inversus in some cases. Congenital heart disease: may present with recurrent respiratory symptoms and failure to thrive. Vocal cord dysfunction: inspiratory stridor, throat tightness, poor response to asthma therapy. Gastroesophageal reflux disease: chronic cough or wheeze related to reflux episodes. Conclusion A structured approach integrating history, examination, and targeted investigations is essential for accurate diagnosis of childhood asthma. Considering alternative diagnoses prevents mislabeling and ensures appropriate management. Reassessment over time is crucial, as respiratory symptoms and lung function patterns evolve with growth and development.