The clinical features of dermatomyositis in a South Australian population

Abstract

Aim: To review the clinical features of dermatomyositis (DM) in a South Australian population. Methods: Retrospective review of medical records of patients with biopsy-proven DM in South Australia from 1990 to 2005. Results: There were 21 cases of biopsy-proven DM in SA (62% F, mean age 49.7 ± 18.4 years) and clinical details were available in 20 of these. Malignancy was identified in 9/20 patients; in five this followed the diagnosis of DM, with three malignancies seen within 3 months of disease onset. Three patients had a clearly defined immune insult prior to the diagnosis of DM; one patient had Mycoplasma pneumoniae infection 23 days prior to DM, two had pneumococcal and influenza vaccinations 5 and 14 days prior to the onset of DM, respectively. Two of three patients with anti-Jo-1 antibody experienced thromboembolism within 2 months of DM onset and three patients had interstitial lung disease (2 with anti-Jo-1 antibody). Creatine kinase (CK) was elevated in 15/20 cases and showed strong correlation with transaminases, and notably not with traditional inflammatory markers. Conclusions: This retrospective review of patients with biopsy-proven DM suggests a role for infection/vaccination in triggering disease onset. A particularly strong association with malignancy was observed and it is suggested that DM may predispose to thrombosis. Transaminases, in addition to CK may be used to monitor disease activity, and traditional inflammatory markers have little role in this.