The diagnosis of asthma in the pediatric patient is a challenge because many young children with asthma have only transient wheezing rather than persistent wheezing. Pediatric patients often appear well and without symptoms between episodes of wheezing or cough.

Consideration of a diagnosis of asthma is often prompted by recurrent episodes of respiratory symptoms. Although there is no single diagnostic test for asthma at any age group, careful review of recent and past history, along with physical examination and selected evaluations, can help the clinician support a diagnosis of asthma.

Many aspects of current and past history as well as physical examination can help the clinician distinguish between transient wheezing and asthma in the young child and confirm asthma in the older child. Although many parents confuse wheezing with upper airway congestion or noisy breathing, a history of previous physician-diagnosed wheezing is helpful to confirm true wheeze.

Most wheezing and coughing in children occur in association with viral illnesses, but wheezing or coughing apart from obvious infection, such as with exercise, activity, exposure to allergens, or exposure to environmental tobacco smoke, suggests more persistent disease.

Additionally, cough that has responded to bronchodilator therapy is consistent with an asthma cough and frequent nocturnal cough may be associated with more severe asthma.

Past medical history, including birth history, prematurity, and history of oxygen requirement or mechanical ventilation, documents important factors that can help clarify the condition of pediatric patients with recurrent respiratory symptoms, especially because often non-atopic infants can have bronchopulmonary dysplasia and airway hyper-responsiveness similar to asthma.

Determining the severity of previous respiratory episodes, including urgent or emergent care, hospitalization, and hypoxia, helps the clinician quantify symptom control and potentially predict subsequent episodes. Previous response to therapy, including bronchodilators and steroids (both inhaled and systemic), can also help confirm a diagnosis of asthma.

Finally, previous history of other allergic conditions increases the risk for developing asthma. The evaluation of a child with recurrent respiratory symptoms should include a thorough review of the family medical history and environmental exposures.

A history of physician-diagnosed asthma in a parent is an important risk factor for persistent wheezing in children. Reviewing the family history for the presence of other atopic disease, such as allergic rhinitis, food allergy, and eczema, help establish an atopic genetic background for the patient.

An environmental history should document the presence of potential perennial allergens in the home, including furred and feathered pets; the use of allergen covers for mattresses and pillows; the frequency of cleaning bed linens; and the presence of carpets, upholstered furniture, and stuffed animals.

Other potential sources of irritation in the home environment include tobacco smoke, cockroaches, fireplaces, home heating systems, and home cooling systems. As mentioned above, children sensitized to certain allergens are more likely to have asthma.

When examining an asymptomatic pediatric patient with recurrent respiratory symptoms, the physical findings are likely normal, but evidence of allergic disease can help confirm asthma. Specifically, an examination that finds nasal edema, rhinorrhea, enlarged turbinates, allergic shiners, and atopic dermatitis establishes allergy.

On the other hand, cystic fibrosis is suggested in the child with nasal polyps. The lung examination should include respiratory rate, auscultation, and oxygen saturation, all of which are likely normal. However, a normal lung examination does not exclude a diagnosis of asthma.

It is during an acute episode that the respiratory examination is most helpful. The presence of wheeze, cough, diminished air movement, retractions, tachypnea, or hypoxia should be documented to help determine severity. In some children with significant airway obstruction, wheezing is not appreciated until some bronchodilation has occurred.