Children who experienced family restructuring during their first year of life had higher odds of developing psoriasis later, according to prospective cohort data from 16,415 Swedish children followed from birth into early adulthood.
The stressful life factor (SLF) of "new family structure"—defined as parental divorce or separation and/or the addition of new adults or step-siblings—before 1 year of age was associated with nearly 4 times higher odds of future psoriasis in univariate analysis and remained significant after adjustment for sex, first-degree psoriasis heredity, maternal ethnicity and education, and passive smoke exposure.
When researchers integrated SLF reports across all follow-ups (years 1, 3, 5, and 8) to capture stress load/persistence, "new family structure" showed nearly 3 times higher odds in univariate analysis, though the association was not significant after adjustment. Effect size remained substantial. In this merged-years approach, an SLF is counted "yes" if it occurred at any time up to the latest follow-up.
The All Babies in Southeast Sweden (ABIS) birth cohort included children born October 1, 1997–October 1, 1999. (response rate; 78.6%). Parents completed questionnaires at birth and at child ages 1, 3, 5, and 8 years, reporting SLFs via checklists adapted from validated scales. Psoriasis cases (n=121; 99 mild cases requiring topical treatment, 22 severe cases requiring systemic treatment) were identified through the Swedish National Patient Register by December 31, 2020, where diagnoses are dermatologist confirmed. Individuals with other autoimmune diseases (n=717) were excluded.
When analyzed by age, only year 1 showed significant associations. In addition to "new family structure," "conflict at home" (exposure to violence/psychological conflict) at year 1 was significant in both univariate and adjusted models. The combination of "new family structure" and "conflict at home" was also significance. No associations were observed at later years.
The authors suggested that early-life stress may trigger increased cortisol concentrations, which influences immune system balance. Children exposed to SLFs have been found to have elevated C-reactive protein levels, and adults who experienced childhood abuse showed higher circulating proinflammatory cytokines than the general population.
Researchers used binomial logistic regression and also ran Firth's penalized logistic regression to address sparse data. No multiple-testing corrections were applied emphasizing effect sizes/precision and the exploratory, hypothesis-driven nature of the work.
These findings extend previous ABIS research linking early-life stressful events increase risk for diabetes-related autoantibodies and clinically manifest type 1 diabetes, and that such factors influence immune system function. Earlier psoriasis studies predominantly examined stressful life factors near diagnosis rather than events occurring years earlier in childhood.
The study was conducted by Debojyoti Das and Johnny Ludvigsson, of the Division of Pediatrics, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden. Limitations included the relatively small number of psoriasis cases, potential recall bias in parent-reported data, possible residual confounding from unmeasured socioeconomic factors, and limited generalizability given the cohort's restriction to southeast Sweden with low population diversity.
The authors declared having no competing interests.
Source: JID Open