Time-dependent risk of atopic dermatitis following nontyphoidal Salmonella infection

Background: The pathogenesis of atopic dermatitis (AD) remains unclear. Nontyphoidal Salmonella (NTS) infection might trigger immune-mediated reactions. We aimed to examine NTS and the risk of subsequent AD. Methods: From 2002 to 2015, eligible patients (aged 0-100 years) with NTS were identified. NTS and non-NTS groups were matched at a 1:10 ratio on age and sex. We utilized conditional multivariable Cox proportional hazard models to estimate the adjusted hazard ratio (aHR) and 95% confidence interval (CI) for AD development. Subgroup analyses were conducted based on age, sex, and severity of NTS infection. We utilized landmark analysis to explore the time-dependent hazard of AD following NTS. Results: In the NTS group (N = 6624), 403 developed AD. After full adjustment of demographics and comorbidities, the NTS group had a higher risk of AD than the reference group (aHR = 1.217, 95% CI = 1.096-1.352). Age-stratified analysis revealed that NTS group exhibited an elevated risk compared to the reference group, particularly among those aged 13-30 years (aHR = 1.25, 95% CI = 1.017-1.559), individuals aged 31-50 years (aHR = 1.388, 95% CI = 1.112-1.733), those aged 51-70 years (aHR = 1.301, 95% CI = 1.008-1.679), and individuals aged 71 years and over (aHR = 1.791, 95% CI = 1.260-2.545). Severe NTS was associated with a higher risk of AD than the reference group (aHR = 2.411, 95% CI = 1.577-3.685). Landmark analysis showed generally consistent findings. Conclusions: Minimizing exposure to NTS infection may represent a prospective strategy for averting the onset and progression of atopic dermatitis. Key messages: What is already known on this topic: AD is particularly susceptible to affronts from the environment. NTS infection has been associated with dysbiosis and autoimmune reactions, which may have a common pathogenesis with AD. What this study adds: NTS had a higher risk of AD than the reference group. Additionally, this risk was even more pronounced in those with severe NTS. How this study might affect research, practice, or policy: Minimizing exposure to NTS infection could be a potential strategy for preventing the onset and progression of AD. The study offers a promising avenue for further investigation into the underlying pathogenesis of AD.