Asthma Diagnosis In Children

Asthma is a chronic respiratory disease, which is usually caused by inflammation of the airways, increased sensitivity of the airways to various that worsen the condition, and obstruction of airflow. However, asthma is different in children and adults on account of various factors. For example, the diagnosis of asthma in children is often much more difficult and they cannot use many drugs that can be used by adults.

For proper diagnosis of asthma in children, it is essential to have a thorough review of their present and past medical records, family history, and a physical test. Sometimes it takes specialized testing for the diagnosis of asthma to exclude other possible factors that cause similar symptoms.

As part of a physical examination, the doctor observes the child as he/she breathes and listens to the child's lungs. The doctor may hear wheezing in case the child has got an asthma attack, although the lungs sound normal between attacks. A physical test will also include examination of the child's eyes, ears, nose, and throat.

Among other tests for the diagnosis of asthma in children are spirometry testing, peak expiratory flow rate measurement, challenge testing, methacholine or cold air challenge, and exercise challenge.



Spirometry testing is the most accurate test for diagnosing asthma, which measures the flow and volume of air generated after a child takes a very deep breath and then forcefully tries to blow all the air out of his/her lungs. Spirometry testing is normally done again after the child uses an asthma inhaler to confirm that the airflow obstruction is reversible. For children between four and six years, it is easier to take peak expiratory flow rate (PEFR) measurements. In this test, the child takes a very deep breath and then quickly blows out as hard as possible into a device called a peak flow meter. This is repeated thrice, with the highest value being considered as the result.

If a child is suspected to have asthma after undergoing spirometry or PEFR, a bronchial challenge testing may be performed. It is designed to cause the airways to narrow in children with asthma and is performed usually in a specialized asthma testing center.

When a child undergoes a methacholine challenge test, he/she inhales a medication called methacholine, which causes the smooth muscles of the airways to constrict, thereby narrowing them.

The methacholine concentration is gradually raised to determine if any of five doses will cause airway narrowing. Before and after each increased dose of methacholine, the child undergoes spirometry testing. Cold air challenge, in which a child breathes in cold air and then performs spirometry testing every few minutes for 20 minutes, is also done in some cases. During an exercise challenge, the child is made to exercise for six to eight minutes, and then spirometry testing is performed every few minutes for 20 minutes.

Other tests may be performed to make sure that another condition is not the cause of a child's coughing or wheezing. These tests may include a chest x-ray, sweat chloride test (for cystic fibrosis), barium swallow (for gastroesophageal reflux), or skin testing (for allergies). Skin or blood testing for allergies may also be recommended in some cases.

Infants and children younger than four years are usually not capable of performing spirometry or peak expiratory flow rate testing. So a doctor often recommends a trial of treatment to confirm the diagnosis.

• Cassandra Bagley
• 14/04/2009, 10:59 PM
• 0 Comments