Rhinoconjunctivitis in 5-year-old children: a population-based birth cohort study

Area of Science:

• Pediatric Allergy and Immunology
• Environmental Health
• Epidemiology

Background:

• Limited data exists on rhinitis prevalence, risk factors, and natural history in early childhood.
• Rhinitis and rhinoconjunctivitis are common conditions with potential long-term health implications.

Purpose of the Study:

• To investigate the prevalence and risk factors of current rhinoconjunctivitis (CRC) at age 5 years within a whole-population birth cohort.
• To identify associations between CRC and other allergic diseases and respiratory outcomes.

Main Methods:

• Prospective follow-up of a birth cohort to age 5 years, utilizing questionnaires, skin testing, specific immunoglobulin E measurements, lung function tests, and dry air challenges.
• Quantification of endotoxin and allergen exposures from dust samples.

Main Results:

• The prevalence of rhinitis ever, current rhinitis, and CRC was 28.2%, 26.1%, and 12.1%, respectively.
• Maternal asthma, paternal hay fever, and sensitization to grass and cat allergens were significant independent risk factors for CRC.
• CRC coexisted with asthma, wheeze, and eczema, but did not affect wheeze severity or lung function in preschool children.

Conclusions:

• Family history of allergic disease and sensitization to inhalant allergens are significant risk factors for rhinoconjunctivitis in preschool children.
• In this age group, rhinoconjunctivitis is not associated with increased wheeze severity, airway reactivity, or reduced lung function.