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.
(© 2015 European Academy of Dermatology and Venereology.)