Patients' demographic, comorbidity profiles vary considerably by myositis subtype

A survey of patients with myositis revealed considerable variation between disease manifestations, but all myositis patients were 23% more likely to have a second autoimmune disorder.

Between December 2010 and July 2012, researchers sent 9,211 questionnaires to people in the U.S. and Canada who had registered with the Myositis Foundation. Patients with adult and juvenile dermatomyositis (DM), polymyositis (PM) inclusion body myositis (IBM) were included. Of 2,209 responses, 1,806 patients met probable or definite Bohan and Peter criteria or possibly Griggs criteria and were included in the study.

Median disease duration was 9.2 years, and patients with IBM were more likely to be older at the time of diagnosis. Most patients were women, except those with IBM. Additionally most patients were white. Black patients were more commonly found to have PM, according to the researchers.

Self-reported diagnosis of the presence of a second autoimmune disorder was 23% likely, with increased odds for rheumatoid arthritis or autoimmune thyroid disease in patients with DM and PM but not IBM. Patients with DM were four times more likely than those with IBM to have systemic erythematosus lupus.

Other findings showed patients with DM and juvenile DM were 85% likely to have a skin rash vs. 14% of patients with PM and 6% of patients with IBM, and 3.8% of patients with DM, 2.1 % of patients with PM and 2.5% of patients with IBM reported some kind of malignancy, excluding skin cancer, within 2 years of myositis diagnosis. – by Shirley Pulawski

Reference:

Faiq A, et al. Paper #2211. Presented at: American College of Rheumatology Annual Meeting. Nov. 14-19, 2014; Boston.

Disclosure: Faiq has no relevant financial interests to disclose. Please see the full study for a list of all other authors’ relevant financial disclosures.