Patients with autoimmune disorders such as systemic lupus erythematosus (SLE) and RF—and in some cases, their first-degree relatives—have higher rates of comorbid OCD and anxiety disorders compared with the general population (Slattery et al. 2004; Hounie et al. 2007). A recent large birth cohort study based on Swedish National Register data also suggested increased rates of multiple autoimmune diseases among adults with OCD as well as their first-degree relatives, including inflammatory bowel disease (IBD), Hashimoto's thyroiditis, celiac disease, psoriasis, type 1 diabetes, idiopathic thrombocytopenic purpura, Sjögren's syndrome, and Guillan-Barré syndrome in addition to scarlet fever (Mataix-Cols et al. 2017).
