Dermatomyositis: factors predicting relapse

Background The course of dermatomyositis (DM) can be chronic with relapses, which are associated with major morbidity. Objective The aim of this study was to identify presentation features that predict DM relapses. Methods We retrospectively reviewed data of patients with DM recorded from 1990 to 2011, including muscle biopsy results. Characteristics of patients with and without relapses were compared. Hazard ratios (HRs) were estimated using a Cox model. Results We identified 34 patients, with a mean age of 46 ± 17 years (range, 18–77) and 24 (71%) women. The muscle and skin abnormalities relapsed in 21 (61%) patients. By univariate analysis, two presentation features were significantly associated with a subsequently relapsing course, namely, dysphonia [HR = 3.2 (1.2–8.5)] and greater skin lesion severity defined as a Cutaneous Disease Area Severity Index [CDASI] > 20 [HR = 3.5 (1.2–7.9)]. Conclusion Dysphonia and skin lesion severity at disease onset must be recorded, as they significantly predict a relapsing disease course.