Allergy from perspective of environmental pollution effects: from an aspect of atopic dermatitis, immune system, and atmospheric hazards-a narrative review of current evidences

Association between parental autoimmune disease and childhood atopic dermatitis varied by sex: a nationwide case-control study

Atopic dermatitis (AD) is a common inflammatory skin disorder induced by dysfunction of immune suppression sharing similar pathogenesis to autoimmune diseases. To explore the association between autoimmune diseases and AD in children, we linked the birth data from National Birth Registry with National Health Insurance Research Database. There were 1,174,941 children obtained from 2006 to 2012 birth cohort. A total of 312,329 children diagnosed with AD before 5 years old were compared to 862,612 children without AD in the control group. Conditional logistic regression was utilized to calculate adjusted odds ratio (OR) and Bonferroni-corrected confidence interval (CI) for overall significance level of 0.05. In 2006-2012 birth cohort, the prevalence rate of AD was 26.6% (95% CI 26.5, 26.7) before 5 years of age. Having parental autoimmune disease (including rheumatoid arthritis, systemic lupus erythematosus, Sjogren's syndrome, ankylosing spondylitis, and psoriasis) was associated with a significant higher risk of children AD development. The other associated factors were maternal obstetric complications (including gestational diabetes mellitus and cervical incompetence), parental systemic diseases (including anemia, hypertension, diabetes mellitus, chronic obstructive pulmonary disease, hyperthyroidism, and obstructive sleep apnea), and parental allergic disease (including asthma and AD). The subgroup analysis showed similar results between children's sexes. Moreover, maternal autoimmune disease had higher impact on the risk of developing AD in the child compared with paternal autoimmune disease. In conclusion, parental autoimmune diseases were found to be related to their children's AD before 5 years old.

The association between non-alcoholic fatty liver disease and atopic dermatitis: a population-based cohort study

Background

In previous studies, it was reported that non-alcoholic fatty liver disease (NAFLD) incidence and prevalence increased in children with atopic dermatitis. Nevertheless, the actual association between the two diseases has not been fully proven in large-scale studies, and real-world evidence is missing. The objective of this nationwide, longitudinal cohort study was to evaluate the association between NAFLD and atopic dermatitis.

Methods

The National Health Insurance Research Database in Taiwan was utilized in this study. Patients with records of NAFLD diagnosis were recruited as the experimental group, and patients having less than three outpatient visits or one inpatient visiting record due to NAFLD were excluded from the study design. Non-NAFLD controls were matched based on a 1:4 propensity score matching. Potential confounders including age, gender, comorbidity, and medical utilization status were considered as covariates. The risk of future atopic dermatitis would be evaluated based on multivariate Cox proportional hazard regression.

Results

Compared with people without NAFLD, a decreased risk of atopic dermatitis in NALFD patients had been observed (aHR = 0.93, 95% CI 0.87-0.98). The trend was especially presented in young NAFLD patients. In patients younger than 40 years old, a 20% decreased risk of atopic dermatitis was reported (aHR = 0.80, 95% CI 0.70-0.92).

Conclusion

People with NAFLD were not associated with an increased risk of atopic dermatitis. Conversely, a 0.93-fold risk was noted in NAFLD patients, compared with NAFLD-free controls. Future studies are warranted to evaluate further the mechanism regarding the interplay between the inflammatory mechanisms of NAFLD and atopic dermatitis.