Diagnosis and Classification of Asthma
in Children 12 Years of Age and Adults

To establish an asthma diagnosis, determine the following:

1. Medical history, including history or presence of episodic symptoms of airflow obstruction (i.e., wheeze, shortness of breath, tightness in the chest, or cough).

• Asthma symptoms vary throughout the day; absence of symptoms at the time of the examination does not exclude the diagnosis of asthma.
• Symptoms worsen in the presence of allergens in the air, irritants, or exercise.
• Symptoms occur or worsen at night, awakening the patient.
• Patient has allergic rhinitis or atopic dermatitis.
• Close relatives have asthma, allergy, sinusitis, or rhinitis.
• Consider work exposures which may contribute to the development of asthma. Click here to learn more about work-related asthma.

2. Physical examination of the upper respiratory tract, chest and skin:

• Hyperexpansion of the thorax
• Sounds of wheezing during normal breathing or a prolonged phase of forced exhalation; absence of symptoms at the time of the examination does not exclude the diagnosis of asthma.
• Increased nasal secretions, mucosal swelling, sinusitis, rhinitis, or nasal polyps
• Atopic dermatitis/eczema or other signs of allergic skin problems

3. Airflow obstruction is at least partially reversible. Use spirometry to:

• Establish airflow obstruction: FEV1 <80 percent predicted; FEV1/FVC <65 percent or below the lower limit of normal. If obstruction is absent, see Additional Tests below.
• Establish reversibility: FEV1 increases ³12 percent and at least 200 mL after using a short-acting inhaled beta2-agonist.
• Older adults may need to take oral steroids for 2 to 3 weeks and then take the spirometry test to measure the degree of reversibility achieved. Chronic bronchitis and emphysema may coexist with asthma in adults. The degree of reversibility indicates the degree to which asthma therapy may be beneficial.

4. Alternative diagnoses are excluded (i.e., vocal cord dysfunction, vascular rings, foreign bodies, or other pulmonary diseases). Additional tests may be needed to exclude other diagnoses, see Additional Tests below.

Additional Tests for Adults and Children

Additional tests may be needed when asthma is suspected but spirometry is normal, when coexisting conditions are suspected or for other reasons. These tests can aid diagnosis or confirm suspected contributors to asthma morbidity (e.g., allergens and irritants).

Once asthma has been correctly diagnosed, the next step in patient care is to classify the severity of the disease. Use the following chart to help you assign a severity level to your patient.

· Patients should be assigned to the most severe step in which any feature occurs. Clinical features for individual children may overlap across steps.

· Percent predicted values for forced expiratory volume in 1 second (FEV1) and percent of personal best for peak expiratory flow (PEF) are relevant for children 4 years old or older who can use these devices. Pulmonary function testing appropriate for the young child may be provided in a specialty practice.

· Patients with more than 2 episodes of asthma symptoms per week (i.e. progressively worsening symptoms that may last hours or days) tend to have moderate-to-severe persistent asthma.

· An individual’s classification may change over time.

· Patients at any level of severity of chronic asthma can have mild, moderate, or severe exacerbations of asthma. Some patients with intermittent asthma experience severe and life-threatening exacerbations separated by long periods of normal lung function and no symptoms.

The next step in caring for your patient with asthma is to develop a treatment plan that addresses their medication needs and avoidance strategies.

Click here to learn more about the stepwise approach recommended by the NIH for the management of asthma in adults and children over 5 years old.
Click here to learn about Asthma Action/Management Plans. 
Click here to learn when to refer patients to an asthma specialist. 
What makes a patient have an increased risk for death from asthma? Click here to find out.

Click here for a pdf, printer-friendly page on diagnosing asthma. You may need to download Adobe Acrobat Reader to view it.