How often do your patients have more than one autoimmune condition at the same time? An increasing area of research shows that this is likely more than coincidence.
In 2009, Italian researchers surveyed 25,885 people and found that those who had an autoimmune disease had a significantly higher probability of having a second autoimmune disease.1
Among the 1,300 people in the study with autoimmune diseases, 95.6% were affected by one autoimmune disorder while the remaining 4.4% were affected by two autoimmune disorders. The researchers hypothesized that there is a potential common mechanism among autoimmune diseases.1 Another study showed that patients with sarcoidosis were more likely to have three autoimmune disorders: autoimmune thyroid disease, Sjögren’s syndrome, and ankylosing spondylitis.2
The hypothesis that the presence of one autoimmune condition increases the likelihood that there is another is rapidly gaining credence. In another type of autoimmune disease, psoriasis, comorbidities are also elevated.3 Not only is psoriatic arthritis present in approximately 30% of psoriasis patients,3 psoriasis is also associated with an increased risk of ulcerative colitis, Crohn’s disease, autoimmune thyroiditis,4 and cardiovascular disease, a phenomenon known as the “psoriatic march.”5
If a patient with one autoimmune condition is likely to have another, then does that mean that a patient with two is even more likely to have another?
In 2011, researchers examined 146 patients with both psoriasis and inflammatory bowel disorder (IBD) and 146 patients with psoriasis only.6 They found that the patients in the “both” category have higher rates of autoimmune thyroiditis (2.1% vs. 6.8%). A meta-review also found that patients with psoriasis were found to have higher rates of celiac disease and a higher rate of IBD (including Crohn’s disease and ulcerative colitis).7
At IFM’s Immune Advanced Practice Module, expert clinicians explain how immune dysfunction emerges, and the shared mechanisms that can cause multiple diagnoses. Learn how to evaluate and recognize the patterns associated with underlying antecedents, triggers, and mediators involved in immune dysfunction and inflammation.
- Sardu C, Cocco E, Mereu A, et al. Population based study of 12 autoimmune diseases in Sardinia, Italy: prevalence and comorbidity. PLoS One. 2012;7(3):e32487. doi:10.1371/journal.pone.0032487.
- Wu CH, Chung PI, Wu CY, et al. Comorbid autoimmune diseases in patients with sarcoidosis: a nationwide case-control study in Taiwan. J Dermatol. 2017;44(4):423-430. doi:10.1111/1346-8138.13654.
- Ruffilli I, Ragusa F, Benvenga S, et al. Psoriasis, psoriatic arthritis, and thyroid autoimmunity. Front Endocrinol. 2017;8:139. doi:10.3389/fendo.2017.00139.
- Antonelli A, Delle Sedie A, Fallahi P, et al. High prevalence of thyroid autoimmunity and hypothyroidism in patients with psoriatic arthritis. J Rheumatol. 2006;33(10):2026-2028.
- Furue M, Kadono T. “Inflammatory skin march” in atopic dermatitis and psoriasis [published online June 15, 2017]. Inflamm Res. doi:10.1007/s00011-017-1065-z.
- Binus AM, Han J, Qamar AA, Mody EA, Holt EW, Qureshi AA. Associated comorbidities in psoriasis and inflammatory bowel disease. J Eur Acad Dermatol Venereol. 2012;26(5):644-650. doi:10.1111/j.1468-3083.2011.04153.x.
- Hsu LN, Armstrong AW. Psoriasis and autoimmune disorders: a review of the literature. J Am Acad Dermatol. 2012;67(5):1076-1079. doi:10.1016/j.jaad.2012.01.029.