Table 1:

Select studies evaluating the association between allergic sensitization and asthma development

Reference	Population	Study Design	Intervention	Other Clinically Relevant Outcomes	Asthma-Related Outcome
Cullinan et al. (2004)53	625 children followed from birth to age 5.5 years	Prospective cohort study	Der p 1 and Fel d 1 allergens measured in homes at 8 weeks of life. Annual interview regarding wheeze. SPT completed at 5.5 years.	10% sensitized to HDM or cat. No relation between allergen exposure and sensitization or wheeze found.	7% had atopic wheeze. Risk of asthma rose at low exposure level and then was attenuated thereafter.
Marks et al. (2006)54	616 children with family history of asthma were randomized antenatally and followed through the first 5 years of life	Prospective RCT	Intervention 1: HDM avoidance vs control Intervention 2: Dietary modification vs control.	HDM avoidance resulted in a decrease in HDM in the child’s bed.	No significant difference in the prevalence of asthma in the HDM avoidance group.
			Assessed for asthma and eczema and had skin prick tests for atopy at age 5.	No significant difference in the prevalence of eczema, or atopy.
Arshad et al. (2007)7	120 infants recruited prenatally from atopic families	Prospective single-blind RCT	Intervention (n=58): Infant Breast-fed by mother on low allergen diet or given extensively hydrolyzed formula. HDM exposure reduced by acaricide and mattress covers. Control (n=62): Standard advice	At age 8, statistically significant decrease in allergic sensitization to foods as well as HDM, AR, AD and atopy in the intervention group.	At age statistically significant decrease in asthma
	Study focused on limiting food and HDM exposure
Scott et al. (2012)8	120 infants recruited prenatally from atopic families	Prospective single-blind RCT	Intervention (n=56): Infant Breast-fed by mother on low allergen diet, or given extensively hydrolyzed formula. HDM exposure reduced by acaricide and mattress covers. Control (n=58): Standard advice	At age 18, no difference in allergic sensitization to foods as well as HDM, or atopy in the intervention group.	At age statistically significant decrease in asthma
	Study focused on limiting food and HDM exposure
Stoltz et al. (2013)40	High-risk children for development of asthma and allergy enrolled in the COAST study	Prospective longitudinal cohort study	Specific IgE measured at 1, 3, 6 and 9 years. Current asthma and AR diagnosed at 6 and 8 years	Sensitization to seasonal allergens more associated with rhinitis risk.	Sensitization to cat and dog associated with increased asthma risk. Sensitization to perennial versus seasonal allergens also associated with asthma risk. Dog exposure at birth associated with decreased asthma risk, regardless of sensitization.
Belgrave et al.(2018)55	1046 patients from ages 5–24 from MAAS and ALSPAC cohorts followed with spirometry to ascertain trajectories of FEV1	Prospective longitudinal cohort study	Factors influencing FEV1 were studied in these two cohorts	Participants with recurrent severe wheeze exacerbation by age 3 years (p=0.048) and allergic sensitization at 3 (p=0.017) had increased likelihood of belonging to the subgroup of persistently low FEV1

Abbreviations-- IT: Immunotherapy, SLIT: Sublingual immunotherapy, SCIT: Subcutaneous immunotherapy, SPT: Skin Prick Test, AR: allergic rhinoconjunctivitis, RCT: Randomized controlled trial, HDM: House dust mite, FEV1: Forced expiratory volume in one second. MAAS: Manchester Asthma and Allergy Study, ALSPAC: Avon Longitudinal Study of Parents and Children