CHARACTERISTICS AND OUTCOME OF PATIENTS WITH DERMATOMYOSITIS IN CENTRAL SAUDI ARABIA, A RETROSPECTIVE EPIDEMIOLOGICAL STUDY

Background: Dermatomyositis (DM) is an autoimmune inflammatory condition that can cause inflammatory myositis along with characteristic skin manifestations.1.It can be associated with significant morbidity including malignancies. Study objectives: Our aim is to study the epidemiology, clinical features, investigations and treatments used in dermatomyositis patients at participating hospitals in central Saudi Arabia. We also aimed to study the prevalence of vitamin D deficiency among dermatomyositis patients. Methods: We conducted our retrospective study at 3 hospitals in central Saudi Arabia using data extracted from electronic medical records (EMR). We included all dermatomyositis seen at follow up in participating hospitals (Prince Sultan Military Medical City, King Faisal Hospital and research center, King Fahad Hospital in Buraidah city) for the period between July 2017- July 2021. Only patients who met the diagnostic criteria of dermatomyositis based on the Bohan and Peter criteria were included. Data obtained from patient medical records included age, sex, investigations and treatment modalities. Statistical analysis was performed using SPSS version 25 Results: Of the 17 patients included in our study, 70% were females 30% were males with with mean age of 32.35 years. Three out of seventeen patients had juvenile dermatomyositis while the remaining 14 patients were diagnosed with classic adult dermatomyositis. Heliotrope rash was the most common skin feature and was found in 76 %. Gottron papules were seen in 65 %, poikloderma was seen in 70% and calcinosis was seen in 23% of patients. 70% of patients reported muscle weakness, 29.4% reported pulmonary symptoms and Gastrointestinal symptoms were seen in 35% of patients. 18% had weight loss, arthralgia was reported in 35% and 23.5% had dysphonia while 35% had dysphagia. Elevation in creatinine kinase (CK) was the most common laboratory abnormality and was seen in elevated in 65% of patients. ESR was elevated in 10/17 (59%), C- reactive protein (CRP) was elevated in 9/17 (52%) and ANA was positive in 6/17 (35%). Serum vitamin D was tested in 14 out of the 17 patients and 10/14 (71%) had low serum vitamin D. All patients received systemic steroids and methotrexate was used in 52% of patients. Mycophenolate mofetil (MMF) was used in 29% of patients and IV immunoglobulin (IVIG) was used in 52% of them. Rituximab was used in 41%, azathioprine in 11%, plasmapheresis in 5% and hydroxychloroquine (HCQ) was used in 17.5% of patients. Conclusion: Clinical features and laboratory findings in our dermatomyositis patients are consistent with those findings reported in other studies from different countries with few minor differences as stated above. Based on our study findings, we suggest that all patients with dermatomyositis to be tested for vitamin D deficiency and treated accordingly given high prevalence of vitamin D deficiency among our study patients