Exercise-Induced Asthma

Diagnosis/Definition

Increased airways reactivity and airways inflammation associated with exercise.
Signs and symptoms include cough, shortness of breath, chest pain or chest tightness, wheezing or exercise intolerance during physical activity.
Signs/symptoms are usually worse with running than with other activities, occur more commonly after vigorous activity, and can be exacerbated by cold air, concurrent URI, or allergy.
The diagnosis can usually be made by assessing response to pre-treatment with a beta agonist (albuterol); a good response makes the diagnosis likely, and a poor response makes it unlikely.
Pulmonary function testing/spirometry (PFT’s) is not necessary to make the diagnosis, but air flow obstruction documented by PFT’s can confirm the diagnosis of asthma.
Other disease entities which can mimic exercise induced asthma include hyperventilation syndrome, psychogenic stridor (paradoxical vocal cord motion), cardiac disease, and poor physical conditioning.

Initial Diagnosis and Management

The treatment of choice is a short-acting beta2 agonist (albuterol) at a dose of 2-4 puffs via metered dose inhaler (MDI) several minutes before commencing exercise. Make sure that the patient has good inhaler technique and consider prescribing a spacer (Aerochamber). Nedocromil or cromolyn (2-4 puffs via MDI) administered shortly before exercise can also be used, but these agents are less effective than albuterol. An excellent response to pre-exercise treatment with these medications makes the diagnosis of exercise induced bronchospasm likely.
Obtain pre and post bronchodilator PFT’s (Refer to the MAMC PEDIATRIC Pulmonary Function Lab).
Normal PFT’s do not rule out exercise induced asthma, but airways obstruction documented on PFT’s is strong evidence for asthma.
Methacholine challenge tests for children should not be ordered by a primary care provider. Exercise challenge tests are often not helpful in making the diagnosis of exercise induced asthma due to their low sensitivity in children.

Ongoing Management and Objectives

The primary objectives are to maintain normal activity levels and prevent any limitation in activity.
Treat other manifestations of asthma. Click here for MAMC Asthma Clinical Standard. In many asthmatic children, exercise induced bronchospasm is a manifestation of persistent asthma which is not being adequately controlled.

Indications for Specialty Care Referral

Children with exercise induced respiratory symptoms, which do not respond well to pre-treatment with albuterol, nedocromil, or cromolyn.

You feel that an exercise pulmonary function study is necessary (Refer to the Pediatric Pulmonary Service for evaluation and not directly to the Pediatric Pulmonary Function Lab).

Children in whom you question the diagnosis, and you would like confirmation by a specialist.

Patients with atypical presentations to include those in whom exercise induced asthma is suspected, but studies as recommended above are normal (Refer to the PEDIATRIC PULMONARY SERVICE).

Criteria for Return to Primary Care