Associations between maternal socioeconomic position and psoriasis: A cohort study among the offspring of the Danish National Birth Cohort

Background
The socioeconomic determinants of paediatric‐onset psoriasis have not been previously investigated. The aim of this study was to identify whether a social gradient exists for paediatric‐onset psoriasis, using measures of maternal socioeconomic position.
Methods
Data on paediatric‐onset psoriasis from 36,003 Danish National Birth Cohort offspring were cross‐linked with nation‐wide registry data on maternal age and three measures of maternal socioeconomic position: maternal educational attainment, maternal labour market attachment and equivalised household income. Univariable and multivariable logistic regression analyses were conducted to estimate the odds ratios (ORs) of offspring psoriasis, in cohort analyses for data from the year of enrolment and cross‐sectional analyses from the year of the 11‐year follow up.
Results
Maternal age at birth, maternal educational attainment, and equivalised household income were inversely associated with offspring psoriasis. Low maternal educational attainment was associated with offspring psoriasis (ORadj 1.62 [1.20‐2.18]) after adjusting for maternal psoriasis and age in cohort analysis. Odds of psoriasis in offspring of mothers in the highest quartile compared to mothers in the lowest quartile of equivalised household income was ORcrude 0.57 (0.43‐0.76), and ORadj 0.59 (0.44‐0.80) after adjusting for maternal psoriasis and age. Similar results were observed for data on maternal socioeconomic position at enrolment and at follow‐up.
Conclusion
A steep social gradient in paediatric‐onset psoriasis was observed. Maternal socioeconomic position may play a role in early life exposure to modifiable risk factors for psoriasis. Future studies may help elucidate which biological factors mediate the social gradient observed in our study.