Asthma Mimics According to GINA Guidelines
According to the Global Initiative for Asthma (GINA) guidelines, several conditions can mimic asthma and should be considered in the differential diagnosis, especially when patients present with respiratory symptoms that do not respond to standard asthma therapy. 1, 2
Large Airway Obstructions
- Foreign body in trachea or bronchus - Consider particularly in children or when symptoms have acute onset 1
- Vocal cord dysfunction (VCD) - Characterized by abnormal adduction of vocal cords during inspiration, often misdiagnosed as asthma; may coexist with asthma 1, 3
- Vascular rings or laryngeal webs - Congenital abnormalities that can cause airway obstruction 1
- Laryngotracheomalacia, tracheal stenosis, or bronchostenosis - Structural abnormalities of the airways that can cause wheezing and dyspnea 1
- Enlarged lymph nodes or tumor - Can cause extrinsic compression of airways 1
Other Respiratory Conditions
- COPD (chronic bronchitis or emphysema) - More common in adults with smoking history; may coexist with asthma 1
- Pulmonary embolism - Can present with acute dyspnea and chest pain 1, 2
- Pulmonary infiltration with eosinophilia - Conditions like allergic bronchopulmonary aspergillosis 1, 3
- Bronchiectasis - Can complicate asthma management and cause persistent symptoms 3
- Respiratory bronchiolitis interstitial lung disease - Can be mistaken for asthma 3
Non-Respiratory Conditions
- Congestive heart failure - Can cause wheezing ("cardiac asthma") and dyspnea 1, 2
- Recurrent cough not due to asthma - Including post-nasal drip, chronic sinusitis 1
- Aspiration from swallowing dysfunction or gastroesophageal reflux - Can trigger cough and wheeze 1
- Cough secondary to medications - Particularly angiotensin-converting enzyme inhibitors 1
- Anaphylaxis - Can present with acute respiratory distress and wheezing 2
- Angioedema - Upper airway obstruction that can mimic asthma symptoms 2
Diagnostic Challenges
- Cough variant asthma - Cough may be the only symptom, especially in children; diagnosis confirmed by response to asthma medications 1
- Vocal cord dysfunction - Often coexists with asthma; characterized by variable flattening of inspiratory flow loop on spirometry; diagnosis requires vocal cord visualization during an episode 1, 3
- Comorbid conditions - GERD, obstructive sleep apnea, and allergic bronchopulmonary aspergillosis may complicate diagnosis and management 1
Diagnostic Approach to Distinguish Asthma from Mimics
- Pulmonary function testing - Spirometry showing reversible airflow obstruction supports asthma diagnosis; additional lung function studies help distinguish COPD (diffusing capacity) or restrictive defects (lung volumes) 1, 4
- Bronchoprovocation testing - With methacholine, histamine, cold air, or exercise challenge when asthma is suspected but spirometry is normal 1
- Imaging - Chest x-ray may exclude other diagnoses 1
- Biomarkers of inflammation - Including fractional exhaled nitric oxide (FeNO), which can help identify eosinophilic airway inflammation 1, 4
Red Flags Suggesting Asthma Mimics
- No history of asthma or only mild asthma presenting with severe symptoms 2
- Lack of response to standard asthma treatments 2, 3
- Atypical presentation or course 1
- Symptoms exclusively during specific activities (may suggest VCD) 1
Special Considerations in Children
- Diagnosis in infants and young children (0-4 years) is particularly challenging due to difficulty obtaining objective lung function measurements 1
- Caution needed to avoid both inappropriate prolonged therapy and underdiagnosis 1
- European Respiratory Society recommends objective testing with spirometry, bronchodilator reversibility, and FeNO as first-line tests in children 5-16 years 4
When signs and symptoms are atypical or there are problems with differential diagnosis, referral to an asthma specialist is recommended. 1