Children with atopic eczema experiencing increased disease severity in the pollen season more often have hay fever at a young age and a dark skin type.

Children with atopic eczema are known to experience seasonal variations in disease severity, with winter being the season in which severity generally increases. There is a lack of knowledge about the subgroup of children that experiences increased severity in spring and summer months. We aimed to investigate which phenotype characteristics best describe children flaring in the pollen season. A retrospective database analysis was conducted, including 110 children with difficult-to-treat atopic eczema aged 0-17 years. Relevant outcome parameters were extracted from medical records. In our population, 36% (n = 40/110) of children reported flares of atopic eczema in the pollen season. These children were more often sensitized to one or more types of pollen (73% [n = 29/40] vs. 28% [n = 10/36], p < 0.0001) and had more patient-reported hay fever (70% [n = 28/40] vs. 19% [n = 7/36], p < 0.0001), compared with children who do not flare in the pollen season. Moreover, children flaring in the pollen season more often had a dark skin type (78% [n = 31/40] vs. 44% [n = 16/36], p = 0.003). Based on stepwise multivariable analyses, children flaring in the pollen season were characterized by the combination of younger age, hay fever, and dark skin type (C-statistic: 0.86). In conclusion, patient-reported flares in spring and summer are experienced by one-third of children with difficult-to-treat atopic eczema. This phenotype can be characterized as young children having hay fever and a dark skin type and can be identified based on clinical parameters alone without the need to perform immunoglobulin E blood testing or skin prick tests.