Asthma is a heterogeneous disease characterised by chronic airway inflammation, defined by a history of respiratory symptoms — wheeze, shortness of breath, chest tightness, and cough — that vary in intensity and over time, together with variable expiratory airflow limitation. Symptoms are typically worse at night or on waking, and are triggered or worsened by exercise, allergen or irritant exposure, changes in weather, or viral respiratory infections.
Confirming variable airflow limitation (GINA)
Confirm the diagnosis objectively before starting controller treatment whenever possible — spirometry reversibility often normalises once inhaled corticosteroids (ICS) are started, making retrospective confirmation harder. Document the objective evidence in the notes at diagnosis.
A normal spirometry performed when the patient is asymptomatic does not exclude asthma, since airflow limitation is characteristically variable. If clinical suspicion remains high, repeat testing when symptomatic, consider a bronchial challenge test, or use a time-limited therapeutic trial with objective reassessment (symptoms and spirometry) before confirming or refuting the diagnosis.
A 28-year-old woman reports episodic wheeze and nocturnal cough. Spirometry today is normal (FEV1/FVC 0.84) and she is asymptomatic. What is the most appropriate next step to confirm or exclude asthma?