A physician is likely to use several methods to diagnose whether or not a child has asthma. A child’s medical history – including prior breathing problems, allergies or skin conditions – may offer important clues. A family history of asthma, allergies or eczema also indicates an increased risk for child asthma.

A complete physical examination also may uncover evidence of asthma. Diagnostic tests that measure a child’s airflow are the primary means of uncovering asthma. These are the same tests used in adults and include pulmonary function tests and spirometry. A chest x-ray may also be used to detect air trapped in the lungs or rule out other conditions and diseases known to cause symptoms similar to asthma.

Since young patients often have difficulty following the instructions given during lung testing, children under the age of 5 cannot usually perform lung function tests. Instead, a physician will often base an asthma diagnosis on the patient’s signs and symptoms, as well as the information collected from a medical history and physical examination. The physician may prescribe a bronchodilator for the child and confirm the diagnosis if the child’s signs and symptoms improve with its use.

Blood testing may be recommended in some children to detect antibodies associated with asthma and allergic reactions. Infants who do not exhibit signs of asthma but nonetheless register elevated levels of immunoglobulin E (IgE) may be at greater risk for developing asthma later in life.

Parents can also play a vital role in the ongoing diagnosis of their child’s asthma by using a peak flow meter. This device measures the amount of air flowing into and out of a child’s lungs. By using it every day, parents can detect changes in a child’s breathing capacity before the condition manifests itself in asthma symptoms. Peak flow meters can also help a parent determine the severity of an asthma attack once it has begun.