Yi-Qi-Pin-Chuan granules: a Chinese medicine for treatment of acute asthma

INTERVENTION: Chinese herbs arm: Chinese herbs and beta‐2‐agonists (salbutamol), systemic steroids (0.5 ‐ 1 mg/kg) if necessary. Placebo arm: placebo and beta‐2‐agonists (salbutamol), systemic steroids (0.5 ‐ 1 mg/kg) if necessary. Period of treatment: 7 days ‐ there is no follow‐up period. CONDITION: Mild to moderate asthma in acute exacerbation ; Respiratory ; Asthma PRIMARY OUTCOME: The number of patients with use of systemic steroids and steroid dose, evaluated at days 4 and 8 SECONDARY OUTCOME: 1. The number of patients with hospital admissions, evaluated at days 4 and 8; 2. The number of puffs of beta agonists (salbutamol), recorded in asthma diary by the patient; 3. Lung functions (PEF), assessed at hours 0, 2, 4, 6, 8, 10, 12 after recruitment, and in morning and evening every day during 7 days of treatment INCLUSION CRITERIA: 1. Mild to moderate asthma in acute exacerbation 2. Male and female patients between 15 and 75 years 3. Within 72 hours of onset of acute asthma 4. Ability to provide written informed consent