Filaggrin null alleles are not associated with hand eczema or contact allergy

BACKGROUND: The filaggrin protein is a key component of stratum corneum and homo- or heterozygotes for the filaggrin variant alleles R501X and 2282del4 have varying degrees of impaired skin barrier. The variant alleles have repeatedly been shown to be associated with atopic dermatitis. Any possible association with hand eczema or contact allergy are unexplored.

OBJECTIVES: To explore associations between the variant alleles, hand eczema, contact allergy and atopic dermatitis.

METHODS: In total, 183 adult individuals participated in a clinical examination of the hands, patch testing and filaggrin genotyping. Children without any evidence of atopic dermatitis from the Copenhagen Prospective Study on Asthma in Childhood (COPSAC) study were used as controls. The chi(2) test was used for comparison of allele frequencies.

RESULTS: The majority (73%) had hand eczema, 25% had contact allergy and 14% had a diagnosis of atopic dermatitis. The association between atopic dermatitis and the filaggrin variant alleles was confirmed (odds ratio 3.5, P = 0.015). Allele frequencies in individuals with hand eczema or contact allergy were not statistically significantly increased.

CONCLUSION: There is no association between the variant alleles and hand eczema or contact allergy.