Pet allergen control measures for allergic asthma in children and adults

Although pet removal has been recommended in guidelines on the management of allergic asthma, pet ownership remains high in families where one or more members have an allergy to pet dander. Allergen control measures such as air filtration units placed in the homes of pet-allergic asthmatics have been used as a means of reducing allergen exposure.

To determine the clinical efficacy of pet allergen control measures in the homes of people with pet-allergic asthma.

An electronic search of the Cochrane Controlled Trials Register was carried out. No restriction was placed on language of publication.

Randomised controlled trials comparing an active allergen reduction measure with control were considered for analysis. Participants had stable pet-allergic asthma.

34 references were identified by electronic searching, but only three appeared suitable for potential inclusion in the review. Two met the inclusion criteria for the analysis. Both examined the effectiveness of air filtration units. Two reviewers extracted data independently. A limited amount of data were usable for a meta-analysis.

Both trials were small (n=22 and n=35). No significant differences were detected between active intervention and control on the primary and secondary outcome measures reported in the studies. Data on absence from school or work were not reported in either study. No meta-analysis could be performed due to lack of common outcomes.

The available trials are too small to provide evidence for or against the use of airfiltration units to reduce allergen levels in the management of pet-allergic asthma. Adequately powered trials are needed. There are no trials of other allergen reduction measures, such as pet washing or possibly pet removal.