Hyperlinear palms are described as a feature of loss-of-function (LoF) variants in Filaggrin (FLG). Fractional exhaled nitric oxide (FeNO) is possibly a marker for Th2 inflammation and is elevated in atopic eczema (AE). We explore the features of participants (age <31 years) with AE of Bangladeshi ethnicity from East London and investigate which factors best distinguish them from Bangladeshi non-AE controls (no personal history of atopic disease in the participant/parents) in a cross-sectional study. Participants were recruited between May 2018 and March 2020. Patterns of palmar linearity were categorised, FeNO recorded and LoF FLG variants were identified using targeted sequencing. These features and general demographics were compared between both groups. Firth’s logistic regression was used and models were compared using the Area Under the Receiver Operator Characteristic (AUROC). Five hundred and seventy seven cases were available (507 with AE and 71 controls). Five palmar patterns were noted. There was at least one LoF FLG variant in 39.3% of AE cases and 16.9% of controls. Adjusted models with palm patterns (AUROC 76.44%) performed better than LoF FLG status (AUROC 68.04%) at distinguishing AE cases from controls. In a FeNO data subset of 445 participants (n=132 were too young for FeNO testing), the individual palm pattern and LoF FLG models performed as well as in the full dataset and the FeNO model had an AUROC of 77.05%. Combination models with included palm patterns and FeNO had an AUROC of 89.10%. The addition of LoF FLG variant status did not improve the palm/FeNO model. These data demonstrate it is possible that dosage of FLG expression (as ‘seen’ within the ridged skin of the palm) is a more relevant factor than just genotype for AE development. The AE-phenotypic association with a putative surrogate marker for Th2 inflammation (FeNO) supports systemic immune activation and thus the need for earlier systemic treatments in AE.

ESDR099 - Palmar hyperlinearity patterns and fractional exhaled nitric oxide identify atopic eczema more effectively than filaggrin variant status

The scientific meeting of the European Society for Dermatological Research (ESDR) is held yearly, usually in September. With an international attendance of more than 1000 skin scientists from around the globe, the four-day event includes short oral presentations from peer-reviewed abstracts, keynote lectures from international experts, sponsored symposia, satellite programs, educational events as well as an important focus on posters, networking and building collaborations amongst scientists. For more information about this year’s meeting visit our website.