The prevalence of allergic diseases in an unselected group of 6-year-old children. The DARC birth cohort study

• Published in: Pediatric allergy and immunology Vol. 19; no. 8; pp. 737 - 745
• Main Authors: Kjaer, Henrik Fomsgaard, Eller, Esben, Høst, Arne, Andersen, Klaus Ejner, Bindslev-Jensen, Carsten
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.12.2008; Blackwell
• Subjects: Allergens - immunology; asthma; Asthma - epidemiology; atopic dermatitis; Biological and medical sciences; birth cohort; Child; Child, Preschool; Cohort Studies; Conjunctivitis, Allergic - epidemiology; Denmark - epidemiology; Dermatitis, Atopic - epidemiology; Female; Follow-Up Studies; food hypersensitivity; Food Hypersensitivity - epidemiology; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Humans; Hypersensitivity, Immediate - epidemiology; Hypersensitivity, Immediate - immunology; Immunoglobulin E - blood; Infant; Infant, Newborn; Male; Medical sciences; Prevalence; Prospective Studies; rhinoconjunctivitis; Sarcoidosis. Granulomatous diseases of unproved etiology. Connective tissue diseases. Elastic tissue diseases. Vasculitis; sensitization; Skin Tests; urticaria; Urticaria - epidemiology; Denmark; Allergy; Pediatrics; Skin disease; Nose disease; Prevalence; Rhinitis; Conjunctiva disease; Conjunctivitis; Epidemiology; Atopy; rhinoconjunctivitis; food hypersensitivity; Immunology; Atopic dermatitis; Cohort study; ENT disease; Bronchus disease; Birth cohort; Sensitization; Obstructive pulmonary disease; Child; Food; Human; Lung disease; Immunopathology; Respiratory disease; Urticaria; Hypersensitivity; Asthma; Eye disease
• ISSN: 0905-6157; 1399-3038
• DOI: 10.1111/j.1399-3038.2008.00733.x

This study determines the prevalence of atopic dermatitis, asthma, rhinoconjunctivitis, food hypersensitivity and urticaria and the frequency of sensitization in children with and without clinical allergic disease. In an ongoing prospective non‐interventional birth cohort study of 562 unselected children, 404 children were subjected to interview, clinical examination, lung function measurements and allergy testing at 6 yr of age. Sensitization measured by skin prick test (SPT) and specific immunoglobulin E (S‐IgE) was determined for 24 different allergens. The 1‐yr period prevalence of atopic dermatitis, asthma and rhinoconjunctivitis was 14.4%, 6.2% and 13.6%. 25.7% of the children suffered from at least one of the three diseases. The frequency of sensitization in children with no disease (controls), any allergic disease, atopic dermatitis, asthma and rhinoconjunctivitis was 17%, 45%, 47%, 56% and 55% (defined as SPT ≥3 mm and/or S‐IgE ≥0.35 kU/l for at least one allergen). Symptoms were linked to sensitization for 44% in the asthma group and 42% in the rhinoconjunctivitis group, whereas sensitization could not be linked to worsening of the eczema in any cases of atopic dermatitis. Overlap between the three diseases was significantly more frequent in sensitized children than in non‐sensitized (19/46 = 41% vs. 9/58 = 16%, p = 0.004). The prevalence of food hypersensitivity and urticaria was 1.2% and 5.4% respectively. In unselected 6 yr old children, approximately half of the children with atopic dermatitis, asthma or rhinoconjunctivitis are IgE‐sensitized. Sensitization tends to link these diseases to each other.