Abstract
Background: Filaggrin null mutations result in an impaired skin barrier function and are associated with atopic dermatitis. Clinical observations suggest a distinct phenotype for patients with the filaggrin null genotype.
Objective: To characterize and compare the clinical presentation and course of atopic dermatitis within the first 7 years of life in children with and without filaggrin null mutations.
Method: The COPSAC cohort is a prospective, longitudinal, birth cohort study of 397 Caucasian children born to mothers with a history of asthma, followed for 7 years with scheduled visits every 6 months as well as visits for acute exacerbations of dermatitis. Atopic dermatitis was defined in accordance with international guidelines and dermatitis reactions were accurately described at every visit using 35 predefined localizations and 10 different characteristics.
Results: A total of 170 (43%) of 397 children suffered from atopic dermatitis before age 7. The R501X and 2282del4 filaggrin null mutations were associated with a higher number of acute visits (3.6 vs. 2.7; p=0.04), more severe dermatitis (moderate-severe SCORAD 44% vs. 31%; p=0.14), more widespread dermatitis (10% vs. 6% of the body, p<0.001), an earlier age at onset of dermatitis (246 vs. 473 days, p<0.0001), dermatitis more often localized at exposed areas (hands, feet, extensor areas, cheeks), and with dermatitis spots characterized by an up regulation in both acute and chronic markers.
Conclusion: Filaggrin mutations represent a genetically defined endophenotype, characterized by early onset and a more severe dermatitis with particular predilection to the exposed areas of the body.
- © 2011 ERS