Diagnosis and management of asthma in preschoolers: A Canadian Thoracic Society and Canadian Paediatric Society position paper

Abstract

Asthma often starts before six years of age. However, there remains uncertainty as to when and how a preschool-age child with symptoms suggestive of asthma can be diagnosed with this condition. This delays treatment and contributes to both short- and long-term morbidity. Members of the Canadian Thoracic Society Asthma Clinical Assembly partnered with the Canadian Paediatric Society to develop a joint working group with the mandate to develop a position paper on the diagnosis and management of asthma in preschoolers. In the absence of lung function tests, the diagnosis of asthma should be considered in children one to five years of age with frequent (≥ 8 days/month) asthma-like symptoms or recurrent (≥ 2) exacerbations (episodes with asthma-like signs). The diagnosis requires the objective document of signs or convincing parent-reported symptoms of airflow obstruction (improvement in these signs or symptoms with asthma therapy), and no clinical suspicion of an alternative diagnosis. The characteristic feature of airflow obstruction is wheezing, commonly accompanied by difficulty breathing and cough. Reversibility with asthma medications is defined as direct observation of improvement with short-acting ß2-agonists (SABA) (with or without oral corticosteroids) by a trained health care practitioner during an acute exacerbation (preferred method). However, in children with no wheezing (or other signs of airflow obstruction) on presentation, reversibility may be determined by convincing parental report of a symptomatic response to a three-month therapeutic trial of a medium dose of inhaled corticosteroids with as-needed SABA (alternative method), or as-needed SABA alone (weaker alternative method). The authors provide key messages regarding in whom to consider the diagnosis, terms to be abandoned, when to refer to an asthma specialist and the initial management strategy. Finally, dissemination plans and priority areas for research are identified.

Figure 1)

Diagnosis algorithm for children one to five years of age. *Documentation by a physician or trained health care practitioner; ^†Episodes of wheezing with/without difficulty breathing; ^‡Severity of an exacerbation documented by clinical assessment of signs of airflow obstruction, preferably with the addition of objective measures such oxygen saturation and respiratory rate, and/or validated score such as the Pediatric Respiratory Assessment Measure (PRAM) score; ^§See Table 3 for dosing; ^¶Based on marked improvement in signs of airflow obstruction before and after therapy or a reduction of ≥3 points on the PRAM score, recognizing the expected time response to therapy; **A conclusive therapeutic trial hinges on adequate dose of asthma medication, adequate inhalation technique, diligent documentation of the signs and/or symptoms, and timely medical reassessment; if these conditions are not met, consider repeating the treatment or therapeutic trial; ^††The diagnosis of asthma is based on recurrent (≥2) episodes of asthma-like exacerbations (documented signs) and/or symptoms. In case of a first occurrence of exacerbation with no previous asthma-like symptoms, the diagnostic of asthma is suspected and can be confirmed with re-occurrence of asthma-like symptoms or exacerbations with response to asthma therapy; ^‡‡≥8 days/month with asthma-like symptoms; ^§§Episodes requiring rescue oral corticosteroids (OCS) or a hospital admission; ^¶¶In this age group, the diagnostic accuracy of parental report of a short-term response to as-needed short-acting β₂-agonist (SABA) may be unreliable due to misperception and/or spontaneous improvement of another condition. Documentation of airflow obstruction and reversibility when symptomatic, by a physician or trained health care practitioner, is preferred; ***Based on 50% fewer moderate/severe exacerbations, shorter and milder exacerbations, and fewer, milder symptoms between episodes. ICS Inhaled corticosteroid

Figure 2)

Treatment algorithm for preschoolers with asthma. *Symptoms occurring ≥8 days/month, ≥8 days/month with use of inhaled short-acting β₂-agonists (SABA), ≥1 night awakening due to symptoms/month, any exercise limitation/month or any absence from usual activities to asthma symptoms; ^†Episodes requiring rescue oral corticosteroids or hospital admission; ‡Asthma education including environmental control and a written self-management plan; ^§Inhaled corticosteroids (ICS) are more effective than leukotriene receptor antagonists (LTRA)