Early childhood risk factors for rhinoconjunctivitis in adolescence: a prospective birth cohort study

Table 1 Potential risk factors for rhinoconjunctivitis (RC), allergic RC and non-allergic RC, at 14 years

Risk factors 0–3 years	Reference
Gender, boys	Girls
Family history of atopic diseases at baseline^a (FH)	No FH
Early sensitization to inhalant allergens^b	No sensitization
Early sensitization to food allergens^c	No sensitization
Food allergy^d (FA)	No FA
Atopic dermatitis^e (AD)	No AD
Early wheeze: at least two episodes of wheezing	No wheeze
Elevated cord blood IgE ≥ 0.3 kU/l (CB-IgE)	CB IgE < 0.3 kU/l
Daily exposure to tobacco smoke from parents or others in the household at more than two visits (ETS)	No ETS
Maternal tobacco smoking in pregnancy	No ETS in utero
Cat and/or dog keeping (pets)	No pets
Exclusive breastfeeding ≥3 months (eBF)	eBF ≤ 3 months
Social class^f	High
Overweight at 3 years (BMI girls ≤17.6 and boys ≤17.8) [27]	No overweight
Cesarean section	No section
Older siblings (siblings)	No older siblings

^aOne of both parents with atopic disease
^bElevated s-IgE (Magic Lite, ALK Abello) for one or more of the inhalant allergens grass, birch, mugwort, horse, cat, dog, Dermatophagoides pteronyssinus, Dermatophagoides farinae, Alternaria alternata or Cladosporium herbarum antibodies at one or more visits up to 3 years
^cElevated s-IgE (Magic Lite, ALK Abello) for one or more of the food allergens cow’s milk, hen’s egg, wheat, peanut, codfish, shrimp or soy at one or more visits up to 3 years
^dFood allergy (FA) was diagnosed by controlled elimination/challenge procedures with a positive oral food challenge (DBPCFC or OCFC) according to EAACI guidelines [28]
^eBased on the Hanifin-Rajka criteria [29]
^fClassified according to the grouping system of the Danish social research institute class 1–5 [30] 1–2 were considered “high”, 3–5 “low”

ISSN: 2045-7022