Prevalence of atopic dermatitis, ichthyosis and filaggrin mutations in adolescents in a middle school in Shanghai

Abstract

Objective To investigate the prevalence and progression process of atopic diseases in adolescents, and to assess their relationship with filaggrin (FLG) mutations. Methods Totally, 334 adolescents aged from 11 to 19 years in a middle school in shanghai were enrolled into this study. A clinical interview was carried out to determine the prevalence of atopic diseases (such as ichthyosis, atopic dermatitis (AD), asthma, rhinitis, etc) in these subjects. Peripheral blood samples were collected from 285 out of the 334 adolescents for screening for common FLG mutations, including 3321delA and K4671X. Five years later, these adolescents were followed up for reevaluation of clinical presentations of atopic diseases. Statistical analysis was carried out by the chi-square test with the SPSS 20.0 software. Results As the baseline survey showed, 19 (5.69%) of the 334 adolescents had AD, 14 (4.19%) had ichthyosis vulgaris, 36 (10.78%) had allergic rhinitis, and 4 (1.20%) had asthma. FLG mutations were observed in 24 (8.42%) of the 285 adolescents. Five years later, 265 adoscents completed the follow-up, and 69 (20.66%) were lost to follow-up. Of the 265 adolescents reevaluated, 13 (4.89%) had AD, 15 (5.64%) had ichthyosis vulgaris, 27 (10.15%) had allergic rhinitis, and 1 (0.38%) had asthma. By the time the second survey was performed, 6 out of the 19 patients initially diagnosed with AD had achieved complete regression, 13 had experienced a marked decrease in SCORing atopic dermatitis (SCORAD) score, and symptoms had disappeared in 9 of the 36 patients initially diagnosed with allergic rhinitis. The frequency of FLG mutations was 10.0% in patients with AD, 55.6% in those with ichthyosis, and 40.0% in those with both AD and ichthyosis, and the development of ichthyosis was associated with FLG mutations (P< 0.001). Conclusions The frequency of common FLG mutations was 8.42% in these adolescents. FLG gene may be a semidominant gene associated with ichthyosis vulgaris, and multiple factors influence its expression. Key words: Dermatitis, atopic; Ichthyosis vulgaris; Adolescent; Mutation; Genes, filaggrin