Background
Immune responses in allergic diseases begin with allergen sensitization which develops in early infancy. Allergen sensitization involves a complex interplay of genetic and environmental factors and sensitization patterns are reported to change with age.
Objective
In this follow-up study, we aim to determine the risk factors of allergen sensitization at 3 years in the GUSTO ( Growing Up in Singapore Towards healthy Outcomes) birth cohort.
Methods
We analyzed the electronic databases of the GUSTO study cohort which was followed up since birth. Interviews were carried out and information gathered included demographics, family history of allergy, social data and lifestyle. Mothers were administered questionnaires to obtain information about their child’s health. Eight hundred and fifty-eight infants who completed skin prick testing (SPT) to the allergens (the inhalant allergens: the house dust mites, Dermatophagoides pteronyssinus, Dermatophagoides farinae, and Blomia tropicalis as well as to the food allergens, egg, peanut and cow’s milk) at 36 months were analysed.
Results
Two hundred children (23.2%) had a positive SPT to dust mites and/or food allergens at 36 months. One hundred and ninety four subjects (22.6%) had a positive SPT to dust mites while 18(2.1%) had a positive SPT to food allergens. Early onset of atopic dermatitis before 6 months
( Adjusted odds ratio (AdjOR) 5.11, 95% Confidence Interval (CI) :1.39-18.83, p =0.01), onset of eczema between 7 months and 12 months (AdjOR 14.43, 95%CI: 1.50-138.62, p=0.02) and having a positive SPT at 18 months(AdjOR 14.29, 95%CI: 4.36-46.72, p=<0.01) were significantly associated with a positive SPT at 36 months.
Conclusions
In conclusion, we found that early onset of atopic dermatitis is a risk factor for allergen sensitization. Sensitization to allergens may occur through the cutaneous route and an impaired skin barrier facilitates this.