Patients with atopic dermatitis (AD) are more likely to have a dermatologic, gastrointestinal, or rheumatologic autoimmune comorbidity compared with people without AD, according to a study in the British Journal of Dermatology.
In this case-control study, researchers examined data from Swedish healthcare registers that included the entire Swedish population of people 15 years of age or older from 1968 through 2016. The investigators identified cases with an inpatient AD diagnosis and/or a specialist outpatient AD diagnosis (n=104,832) as well as sex- and age-matched healthy control participants (n=1,022,435). The mean age of the overall population was 34.9 years.
Compared with healthy control participants, patients with AD were significantly more likely to have 1 or more autoimmune disease (adjusted odds ratio [aOR], 1.97; 95% CI, 1.93–2.01). Overall, AD was strongly associated with autoimmune disorders involving the skin (aOR 3.10, 95% CI 3.02–3.18), the gastrointestinal tract (aOR, 1.75; 95% CI, 1.69–1.82), or the connective tissue (aOR 1.50, 95% CI 1.42–1.58).
The association of AD and autoimmune disease was particularly strong in the presence of multiple autoimmune skin comorbidities, including dermatitis herpetiformis (aOR, 9.76; 95% CI, 8.10–11.76), alopecia areata (aOR, 5.11; 95% CI, 4.75–5.49), and chronic urticaria (aOR, 4.82; 95% CI, 4.48–5.19).
Overall, men had a stronger association (P =.000) of AD and autoimmune diseases (aOR, 2.18; 95% CI, 2.10–2.25) compared with women (aOR, 1.89; 95% CI, 1.85–1.93). This sex difference was only significant in AD and rheumatoid arthritis as well as in AD and celiac disease.
Limitations of this study included the lack of primary care AD diagnoses and the lack of information on the relationship of different severities of AD with autoimmune diseases.
The study investigators concluded that increased “awareness, screening, and monitoring of comorbidities may relieve the disease burden in patients with AD and may give deeper insight into its pathogenesis.”
Ivert LU, Wahlgren CF, Lindelöf B, Dal H, Bradley M, Johansson EK. Association between atopic dermatitis and autoimmune diseases: a population-based case-control study. Published online October 22, 2020. Br J Dermatol. doi:10.1111/bjd.19624