Asthma COPD overlap syndrome
Asthma–COPD Overlap Syndrome (ACOS) refers to patients exhibiting features of both asthma and COPD, including persistent airflow limitation and variable airway hyperreactivity.
⚠️ ACOS is associated with worse outcomes than asthma or COPD alone, requiring careful diagnosis and combined treatment strategies.
🔬 Pathophysiology
- 🌪️ Asthma Component: Chronic airway inflammation, eosinophilic infiltration, reversible obstruction (bronchospasm).
- 🔥 COPD Component: Irreversible obstruction, neutrophilic inflammation, alveolar destruction (emphysema) or chronic bronchitis.
- ⚡ Overlap Features: Persistent inflammation, airway hyperreactivity, incomplete reversibility of obstruction.
⚠️ Risk Factors
- 🚬 Smoking: Major COPD driver; smokers with asthma are at highest risk.
- 👵 Age: More common in older adults.
- 🏭 Occupational Exposure: Dust, fumes, chemicals.
- 🧬 Genetics: Family history of asthma or COPD.
🩺 Clinical Features
- 😮💨 Dyspnoea: progressive breathlessness, worse on exertion
- 🤧 Chronic cough with sputum (COPD-like)
- 🎵 Wheeze: episodic, asthma-like
- 📈 Frequent exacerbations
- 🌙 Nocturnal symptoms (asthma feature)
- 🫁 Spirometry: persistent airflow limitation, partial reversibility
- Exam: wheeze, hyperinflation, prolonged expiration
🧪 Investigations
- 📉 Spirometry:
- FEV1/FVC < 0.7 (fixed obstruction)
- Partial reversibility: ≥12% & 200 mL FEV1 improvement, but incomplete normalization
- 🧪 Biomarkers:
- Peripheral eosinophilia → asthma component
- FeNO ↑ → eosinophilic inflammation
- 🩻 Imaging:
- Chest X-ray: hyperinflation, bronchial wall thickening
- CT: emphysema, airway changes
💊 Pharmacological Management
- 🌿 ICS: reduce inflammation, prevent exacerbations (asthma features)
- 💨 LABA: bronchodilation (always with ICS)
- 🛑 LAMA: target COPD component, reduce exacerbations
- 🚑 SABA/SAMA: rescue therapy (e.g., salbutamol, ipratropium)
- ⚡ Oral steroids: only for acute exacerbations
- 🍃 LTRA: for allergic/asthmatic overlap
🏃♂️ Non-Pharmacological Management
- 🚭 Smoking cessation
- 🏋️♀️ Pulmonary rehabilitation: exercise + education
- 💉 Vaccinations: annual influenza + pneumococcal
- 📘 Self-management: inhaler technique, exacerbation recognition
🚨 Exacerbation Management
- 💨 Short-acting bronchodilators (SABA/SAMA)
- 💊 Systemic steroids: oral prednisolone or IV hydrocortisone
- 🧫 Antibiotics: if bacterial infection suspected
- 🫁 Oxygen: if SpO₂ < 90%; monitor CO₂ retention
📉 Prognosis
ACOS has worse outcomes than asthma or COPD alone, including more frequent exacerbations, hospital admissions, and faster lung function decline.
✨ Early recognition, combination therapy (ICS + LABA/LAMA), and lifestyle interventions improve symptom control and quality of life.
📚 NICE References
