BACKGROUND: Common filaggrin (FLG) null mutations are associated with severe and early onset of atopic dermatitis (AD). To date, few studies have investigated anatomical patterns of dermatitis and none has been conducted in the general population.

OBJECTIVE: We evaluated patterns of dermatitis in an adult general population stratified by FLG genotype.

METHODS: Data from a population-based cohort study with a 5-year follow-up were used. This study included 2143 participants aged 18 to 72 years. Information about dermatitis on the hands; feet; face; axillae; and abdomen, chest, or back was obtained by use of questionnaires. Participants were genotyped for common FLG mutations. A history of AD was defined by the United Kingdom Working Party's diagnostic criteria.

RESULTS: The frequency of foot dermatitis in the general population was associated with FLG genotype (P = .014). However, when stratification of FLG genotype and AD was performed, we found that FLG mutations increased the prevalence (odds ratios) of foot dermatitis (odds ratio 10.41; 95% confidence interval 5.27-20.60) and persistent hand dermatitis (odds ratio 17.57; 95% confidence interval 8.60-35.89) only in participants with AD.

LIMITATIONS: Potential misclassification and recall bias are study limitations.

CONCLUSION: FLG mutations affected the lifetime prevalence of hand and foot dermatitis in participants with a history of AD.