COMORBID autoimmune disease has been linked to diagnosis with atopic dermatitis in patients over 15 years. Case control study data from Sweden have highlighted that diagnosis with atopic dermatitis was nearly twice as likely to be associated with an autoimmune disease.
Atopic dermatitis is known to be associated with allergic diseases of atopy, but associations with nonatopic conditions are building greater evidence. Study author Dr Lina Ivert, Karolinska Institutet, Stockholm, Sweden highlighted that increasing evidence links atopic dermatitis to cardiovascular disease, some cancers, and neuropsychiatric disorders; and there is growing evidence suggesting that some skin and gastrointestinal autoimmune conditions are more common in patients with atopic dermatitis.
The large-scale, case-control study used Swedish population registries to investigate associations between atopic dermatitis and a spectrum of autoimmune diseases. Using data from 1964–2001 from both inpatients and specialist outpatient clinics, 104,832 patients with atopic dermatitis were identified and matched with 1,022,435 general population control patients. To support the validity of the findings, beyond the large data set, researchers also noted that 80% of patients received their atopic dermatitis diagnosis in a dermatology department, for reliable diagnosis.
The adjusted odds ratio (aOR) for autoimmune disease in patients with atopic dermatitis was 1.97 (95% confidence interval [CI]: 1.93–2.01). This association was evident in several body systems, but particularly skin and gastrointestinal autoimmune conditions. The specific conditions with strongest associations with atopic dermatitis were dermatitis herpetiformis (aOR: 9.76; 95% CI: 8.10–11.8), alopecia areata (aOR: 5.11; 95% CI: 4.75–5.49), and chronic urticaria (aOR: 4.82; 95% CI: 4.48–5.19). The odds ratio for atopic dermatitis among patients with two or more autoimmune diseases showed a stronger association; aOR for atopic dermatitis in patients with 3–5 autoimmune diseases was 3.33. Overall, the associations between atopic dermatitis and autoimmune diseases were stronger in men, but sex difference was only statistically significant for associations with rheumatoid arthritis and with coeliac disease.
The clinical implications of these population data findings were considered by Prof Jonathan Silverberg, George Washington University, Washington, D.C., USA: “At a high level, it is important for clinicians to recognise that atopic dermatitis is a systemic immune-mediated disease. Atopic dermatitis is associated with higher rates of comorbid autoimmune disease, similar to psoriasis and other chronic inflammatory skin diseases.”