Association between atopic dermatitis and febrile seizure in young children

Atopic dermatitis is associated with mental health and epileptic seizure in adults, which are attributed to inflammatory cytokine dysregulation, resulting in neuromodulatory dysfunction and neuronal hyperexcitability. The aim of the study is the investigation the potential association between atopic dermatitis and febrile seizure in young children. Data of children born in Korea were obtained from the National Health Insurance Service claims database, which is linked to the National Health Screening Program for Infants and Children database. We analyzed health insurance data at birth from 2008 to 2012 who were followed up until December 31, 2018. The exposure was atopic dermatitis, defined operationally in NHIS claims data as ≥ 5 L20.x diagnoses and ≥ 2 topical corticosteroid prescriptions during the study period; the primary outcome was febrile seizure (ICD-10 codes R56.00 and R56.01) occurring after the index date between 6 months and 6 years of age. The exposed cohort comprised 69,238 children, who were matched with an unexposed cohort of the same size. The median age at atopic dermatitis diagnosis was 2.5 months, and 49.5% were male. During a mean follow-up period of 4.4 ± 0.6 years, the incidence of febrile seizure in the atopic dermatitis group was approximately 8% higher than that in the control group (adjusted hazard ratio: 1.079, 95% confidence interval: 1.02–1.14). The incidence of febrile seizure was 36.5 per 10,000 person-years in the exposed cohort and 33.5 per 10,000 person-years in the unexposed cohort, yielding an absolute rate difference of 3.0 per 10,000 person-years (95% confidence interval: 1.05–4.94). This association remained consistent in propensity score–weighted analyses, across seizure-disorder subgroups, and with lag-time extensions. Atopic dermatitis was associated with a modest but statistically significant increase in the risk of febrile seizure in young children. Further studies are required to clarify the biological mechanism underlying this relationship.