From the Guidelines
Asthma diagnosis should be based on a combination of clinical evaluation, medical history, and lung function tests, with spirometry being the most essential objective measure to establish the diagnosis, as recommended by the European Respiratory Society clinical practice guidelines for the diagnosis of asthma in children aged 5-16 years 1. To diagnose asthma, the clinician should determine that episodic symptoms of airflow obstruction or airway hyperresponsiveness are present, and airflow obstruction is at least partially reversible, measured by spirometry, with an increase in FEV1 of >200 mL and 12% from baseline measure after inhalation of short-acting b2-agonist (SABA) 1. Some key symptom indicators for considering a diagnosis of asthma include:
- Cough (worse particularly at night)
- Recurrent wheeze
- Recurrent difficulty in breathing
- Recurrent chest tightness
- Symptoms occur or worsen in the presence of exercise, viral infection, inhalant allergens, irritants, changes in weather, strong emotional expression, stress, menstrual cycles, or at night, awakening the patient. The recommended methods to establish the diagnosis are:
- Detailed medical history
- Physical examination, which may reveal findings that increase the probability of asthma, but the absence of these findings does not rule out asthma
- Spirometry, which can demonstrate obstruction and assess reversibility in patients 5 years of age Additional tests may include peak flow monitoring and bronchoprovocation tests, but these are not essential for diagnosis, as stated in the European Respiratory Society clinical practice guidelines for the diagnosis of asthma in children aged 5-16 years 1. It's also important to consider a differential diagnosis of asthma, as recurrent episodes of cough and wheezing can be caused by other conditions, and to rule out other diagnoses using additional tests such as chest X-rays or blood tests, if necessary, as recommended by the expert panel report 3 (EPR-3) guidelines for the diagnosis and management of asthma 1. In children aged 5-16 years, the diagnosis of asthma can be confirmed using a diagnostic algorithm that includes spirometry, bronchodilator reversibility (BDR) testing, and exhaled nitric oxide fraction (FeNO) measurement, as recommended by the European Respiratory Society clinical practice guidelines for the diagnosis of asthma in children aged 5-16 years 1. The task force agreed that no single test on its own is currently sufficient to confirm the diagnosis of asthma, and that two positive, evidence-based tests are required to confirm the diagnosis in children aged 5–16 years, as stated in the European Respiratory Society clinical practice guidelines for the diagnosis of asthma in children aged 5-16 years 1. Early diagnosis is crucial as proper management can prevent permanent airway damage and maintain normal lung function, and the diagnosis of asthma depends entirely on a significant improvement in lung function after the trial of treatment, as recommended by the European Respiratory Society clinical practice guidelines for the diagnosis of asthma in children aged 5-16 years 1.
From the Research
Asthma Diagnosis
- Asthma is a heterogeneous clinical syndrome primarily affecting the lower respiratory tract, characterized by episodic or persistent symptoms of wheezing, dyspnea, and cough 2.
- The diagnosis of asthma requires the presence of these symptoms and demonstration of reversible airway obstruction using spirometry 2.
- Identifying clinically important allergen sensitivities is useful in the diagnosis of asthma 2.
- A bronchial provocation test should be considered when forced expiratory volume in one second (FEV1) is ≥70% predicted, excluding respiratory infections within the past 4 weeks 3.
- Diagnostic anti-inflammatory therapy may be initiated to confirm the diagnosis if certain criteria are met, such as positive results in peak expiratory flow-based bronchodilation test or FEV1 variability ≥12% and absolute change ≥200 ml between two prior tests 3.
Diagnostic Criteria
- The diagnosis of asthma can be confirmed by a presumptive diagnostic pathway if clinical symptoms suggest asthma but the bronchial provocation test is not available or does not meet the diagnostic criteria for variable airflow limitation 3.
- Induced sputum eosinophil is one of the gold standard biomarkers for airway inflammation assessment, asthma phenotype classification, corticosteroid response prediction, and exacerbation risk assessment 3.
- Peripheral blood eosinophil ≥ 150/μl can be used to identify eosinophil phenotype or type 2 inflammatory endotype, as well as one of the key biomarkers to predict and evaluate biologic responses 3.
Clinical Assessment
- Clinical diagnosis of asthma is often based on the presence of symptoms, such as cough, wheeze, breathlessness, and chest tightness, but clinical correlation with spirometry and other diagnostic testing is essential 4.
- The focus of care should be toward control of the disease once a diagnosis of asthma is established 4.
- Asthma is characterized by variable airway obstruction, airway hyperresponsiveness, and airway inflammation, and management of persistent asthma requires avoidance of aggravating environmental factors, use of short-acting β2-agonists for rapid relief of symptoms, and daily use of inhaled corticosteroids 2.