Analysis of Prevalence of Anemia according to Severity of Atopic Dermatitis

Abstract

Background: Inflammatory diseases can increase the prevalence of anemia. Recent studies confirmed that the prevalence of anemia is increased by atopic dermatitis (AD), a chronic inflammatory disease. Therefore, we aimed to elucidate the correlation between AD severity and prevalence of anemia. Methods: We used data of pediatric patients from the Health Insurance Review and Assessment Service (HIRA-PPS-2016). We included pediatric patients ( < 18 years) with AD diagnosis who were prescribed medications for AD. We applied a propensity score method with inverse probability of treatment weighting (IPTW) adjusting for differences in prevalence of confounders and performed IPTW logistic regression to evaluate associations between the anemia and severity of AD. Results: In total, 91,501 patients (mild AD: 47,054 patients; moderate-to-severe AD: 44,447 patients) < 18 years who were prescribed drugs for AD were analyzed. Analysis of the probability of patients with mild AD and prevalence of anemia as a reference revealed an odds ratio (OR) of 1.159 (95% CI, 1.109-1.212; p < 0.001) in moderate-to-severe AD patients, indicating a correlation between anemia prevalence and AD severity. Subgroup analysis according to gender, age group, and type of health insurance revealed there was an association between AD severity and anemia except in patients equal or older than 7 years. Conclusion: The prevalence of anemia increased with AD severity despite adjusting for confounding factors. Our results support the hypothesis that AD can cause anemia, and anemia prevalence could be increased in severe AD patients. Further studies are needed to establish a pathological basis.