Patients with atopic dermatitis (AD) have an increased risk for multiple autoimmune disorders, particularly those who have more severe AD, according to findings from a study published in the Journal of Allergy and Clinical Immunology.
Researchers analyzed data from the Oxford-Royal College of General Practitioners Research and Surveillance Centre primary care database to assess the co-occurrence of common autoimmune disorders and determine whether the risk for autoimmune disease is related to AD severity.
All children and adults with newly diagnosed AD from 2009 through 2018 were eligible for inclusion. The following common autoimmune disorders were included in the analysis: Crohn disease, ulcerative colitis, celiac disease, pernicious anemia, type 1 diabetes, autoimmune hypothyroidism, Grave disease, psoriatic arthritis, rheumatoid arthritis, ankylosing spondylitis, systemic lupus erythematosus, Sjögren syndrome, vitiligo, alopecia areata, and multiple sclerosis.
A total of 173,709 patients with AD (mean age, 27.6 ± 28.6 years; 52.9% women) were matched with 694,836 control participants (mean age, 26.7 + 28.0 years; 52.6% women). The control participants had at least 1 year of follow-up to minimize the risk for a nonrecorded AD diagnosis.
At their diagnosis, patients with AD had a higher prevalence of autoimmune disorders compared with the control participants (AD cases’ overall autoimmune condition prevalence, 5.84% [95% CI, 5.73-5.95]; control group, 4.31% [95% CI, 4.26-4.36]; P <.001). Adjusted analysis demonstrated an association between AD and new onset of any autoimmune disorder (adjusted hazard ratio [aHR], 1.28 [95% CI, 1.23-1.34], P <.001).
Associations were found between AD and Crohn disease, ulcerative colitis, pernicious anemia, autoimmune hypothyroidism, rheumatoid arthritis, psoriatic arthritis, Sjögren syndrome, vitiligo, and alopecia areata (aHR range, 1.17-2.06).
Increasing AD severity was associated with an increased risk for autoimmune disease, with aHRs compared with control participants of 1.99 (95% CI, 1.77-2.23; P <.001) for more severe AD; 1.33 (95% CI, 1.19-1.49; P <.001) for moderate AD; and 1.22 (95% CI, 1.16-1.28; P <.001) for mild AD.
The increased risk for autoimmune disease in patients with AD compared with control participants was consistent in subgroups based on sex, deprivation, ethnicity (White, Black, and Asian subgroups), and age (<18, 18-49, 50+ years) (aHR range, 1.12-1.78; all P <.01).
Children with more severe AD had a greater risk for autoimmune disease (aHRs: more severe AD, 2.41 [95% CI, 1.88-3.07]; moderate AD, 1.23 [95% CI, 0.88-3.07]; and mild AD, 1.03 [95% CI, 0.93-1.15]). Individual autoimmune disorders with positive associations with AD were found for vitiligo (aHR, 1.70 [95% CI, 1.38-2.11]) and alopecia areata (aHR, 1.33 [95% CI, 1.07-1.64]).
The absence of verification of physician-coded diagnoses is a study limitation noted by the investigators. Some cases coded as AD may be incorrectly diagnosed, and referral to dermatology was used as a proxy of more severe AD, they wrote.
“Our study underscores the need for increased clinician awareness of the burden of autoimmune comorbidities in patients with AD, and it highlights a need for expert guidance on screening recommendations in clinical practice,” the researchers commented.
Disclosure: This research was sponsored by Pfizer. Several of the study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
de Lusignan S, Alexander H, Broderick C, et al. Atopic dermatitis and risk of autoimmune conditions: population-based cohort study. J Allergy Clin Immunol. Published April 22, 2022. doi:10.1016/j.jaci.2022.03.030