[Atopic dermatitis. Allergological characteristics and association with respiratory disease].

BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory skin disease that frequently precedes the development of asthma or other respiratory allergies. The aim of this study was to review allergen sensitization, type of feeding in infancy, and development of asthma or rhinitis in a group of patients with AD.

METHODOLOGY: One hundred children with AD were selected. All patients underwent skin prick and patch tests to foodstuffs and inhalant allergens, total and specific IgE determination, and oral challenge tests.

RESULTS: The study included 57 boys and 43 girls. The mean age at consultation was 3.77 +/- 2.81 years and mean age at onset of of AD was 1.09 +/- 1.69 years. Twenty-eight percent of the children were exclusively sensitized to food allergens, 20% to inhalant allergens and 22% to both food and inhalant allergens. Mean serum IgE levels were higher in children sensitized to Dermatophagoides pteronyssinus (DPT) (346.86 +/- 430.43 U/ml) than in non-sensitized children (78.24 +/- 132.93 U/m) (p < 0.001). Total IgE levels were also higher in patients with respiratory symptoms (283.77 +/- 336.53 U/ml) than in children without respiratory disease (124.62 +/- 285.21 U/ml) (p = 0.021). Thirty-five percent of the children developed some kind of respiratory allergic disease (asthma and/or rhinitis) in a mean interval of 2.55 years after the onset of dermatitis. Of the children sensitized to inhalant allergens (DPT), 55.26 % developed respiratory symptoms compared with 22.58 % of the non-sensitized children (p < 0.001). The odds ratio of developing respiratory allergy if the patient showed sensitization to DPT was 4.235 (95 % CI 1.768-0.147, p = 0.002).

CONCLUSIONS: Children with AD that develops in the first year of life, associated with high IgE levels and early sensitization, independently of the kind of feeding, develop respiratory allergic disease more frequently than children without these factors.