Asthma COPD overlap syndrome
Asthma–COPD Overlap Syndrome (ACOS) is a condition where patients exhibit clinical and physiological features of both asthma and chronic obstructive pulmonary disease (COPD).
It involves persistent airflow limitation with variable airway hyperreactivity.
⚠️ ACOS has worse outcomes than asthma or COPD alone, making diagnosis and treatment more challenging.
🔬 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: Key driver of COPD; smokers with asthma at highest risk.
- 👵 Age: More common in older adults.
- 🏭 Occupational Exposure: Dusts, fumes, chemicals.
- 🧬 Genetic Factors: Family history of asthma or COPD.
🩺 Clinical Features
- 😮💨 Dyspnoea: Progressive breathlessness, worse on exertion.
- 🤧 Chronic Cough + Sputum: (more COPD-like).
- 🎵 Wheeze: Episodic, often asthma-like.
- 📈 Frequent Exacerbations: Higher than asthma/COPD alone.
- 🌙 Nocturnal Symptoms: Night cough or wheeze (asthma feature).
- 🫁 Airflow Limitation: Spirometry: persistent obstruction, partial reversibility post-bronchodilator.
- Exam: wheeze, hyperinflated chest, prolonged expiration.
🧪 Investigations
- 📉 Spirometry:
- FEV1/FVC < 0.7 (fixed obstruction).
- Partial reversibility: ≥12% & 200 mL FEV1 improvement, but not full normalization.
- 🧪 Biomarkers:
- Peripheral eosinophilia → asthma component.
- FeNO ↑ → eosinophilic inflammation.
- 🩻 Imaging:
- Chest X-ray: hyperinflation, bronchial wall thickening.
- CT: emphysema, airway changes.
💊 Pharmacological Management
- 🌿 ICS: First-line for asthma features (↓ inflammation, ↓ exacerbations).
- 💨 LABA: Bronchodilation (always in combination with ICS).
- 🛑 LAMA: Key for COPD component, reduces exacerbations.
- 🚑 SABA/SAMA: Rescue therapy (e.g., salbutamol, ipratropium).
- ⚡ Oral Steroids: Only for acute exacerbations.
- 🍃 LTRA: For allergic/asthmatic overlap cases.
🏃♂️ Non-Pharmacological Management
- 🚭 Smoking Cessation: Crucial step to prevent progression.
- 🏋️♀️ Pulmonary Rehabilitation: Exercise + education → improves QoL.
- 💉 Vaccinations: Annual flu + pneumococcal vaccine.
- 📘 Self-Management: Patient education on inhaler use, exacerbation recognition.
🚨 Exacerbation Management
- 💨 SABA/SAMA: Short-acting bronchodilators for relief.
- 💊 Systemic Steroids: Oral prednisolone or IV hydrocortisone.
- 🧫 Antibiotics: If bacterial infection suspected (purulent sputum, fever).
- 🫁 Oxygen: If SpO₂ < 90% (beware CO₂ retention in COPD).
📉 Prognosis
ACOS has a worse prognosis than asthma or COPD alone.
➡️ More frequent exacerbations, hospital admissions, and faster lung function decline.
✨ With early recognition, combination therapy (ICS + LABA/LAMA), and lifestyle changes, patients can achieve improved symptom control and quality of life.
