Background Dermatomyositis (DM) is a rare disease that may affect the skeletal muscles and the skin. Literature data on its incidence and prevalence are limited. There is no data on its incidence or prevalence in Turkey.
Objectives In our study, we determined the epidemiology, general clinical features and outcomes of DM based on hospital-based data in Thrace region, which is in northwestern Turkey.
Methods Patients diagnosed with DM at the Trakya University Medical Faculty, Department of Rheumatology November 2004 and November 2014 were reviewed retrospectively. Patients' clinical features, laboratory measurements, demographics, treatments, follow-up durations, disease courses, outcomes and complications were evaluated. As a tertiary care center for rheumatologic diseases, our hospital serves approximately 620,447 adults (306,036 females and 314,411 males) from both rural and urban areas. The population number was obtained from the 2012 census data of the Turkish Statistical Institution, and this population remained stable during 2004–2014. Pediatric patients (<16 years) were not included. Edirne city is located in Thrace region, in northwestern part of Turkey; and it makes borders with Greece and Bulgaria. Our hospital is the only tertiary care reference center for rheumatic diseases for both Edirne and Kırklareli, another city to the north of Edirne.
Results Our study included 23 patients with dermatomyositis. Of them, 14 (60.9%) were females and 9 (39.1%) were males (female to male ratio: 1.55). Over the course of the study, the annual incidence of dermatomyositis was 3.7/1,000,000 (95%CI: 0–18.8); and the overall prevalence was 32.2/1,000,000 (95%CI: 18.1–46.3). Incidence in women was higher 4.6/1,000,000 (95%CI: 0–28.6) compared to men 2.9/1,000,000 (95%CI: 0–21.6). Heliotrope rash (82.6%), gottron papules (87%), proximal myopathy (78.3%) and facial erythema (60.9%). As the first-line treatment, the classic dm patients were given steroid 18 (100%), hydroxychloroquine 16 (88.6%), methotrexate 11 (61.1%) or azathioprine 4 (22.2%) treatment and the amyopathic dm patients were given steroid 3 (60%), hydroxychloroquine 5 (100%) or azathioprine 1 (20%) treatment. The median duration of follow-up in all DM patients was 60 months (range 3–132 months). We observed recurrence in 7 patients during follow-up. We increased the dose of the steroid upon recurrence in all our recurring patients. We added a combination of hydroxychloroquine and methotrexate to treatment upon recurrence in 2 patients receiving steroid alone; and in 3 patients receiving a combination of steroid and hydroxychloroquine at baseline, we added methotrexate upon recurrence and we added azathioprine to treatment in one patient with interstitial pulmonary disease upon recurrence. One patients who did not respond to current therapies, whose condition recurred frequently or had was given cyclosporine and intravenous immunoglobulin.
Conclusions In conclusion, in our hospital-based study on DM for which very limited epidemiological data is available, we observed lower frequency than in North American studies. Female gender was more common in our series. Data in this study is the first epidemiological data on DM reported from Turkey.
Disclosure of Interest None declared