DERMATOMYOSITIS WITHOUT MUSCLE WEAKNESS - LONG-TERM FOLLOW-UP OF 12 PATIENTS WITHOUT SYSTEMIC CORTICOSTEROIDS

Background and Design: We retrospectively studied 12 patients with der matomyositis (DM) with at least one laboratory criterion of muscle inv olvement but without muscle weakness. We reported their outcome withou t systemic corticosteroid treatment and searched for distinctive basel ine data and associated neoplasia among a group of 29 patients with cl assic DM. Results: After a mean follow-up of 5.3 years, complete or pa rtial skin improvement occurred in nine patients with DM without muscl e weakness, and muscle enzyme levels were normalized in all. When comp ared with the classic DM group, no statistical differences were found for associated neoplasia or for any baseline data studied except, as e xpected, for muscle parameters. Conclusions: The lack of distinctive b aseline data between DM without muscle weakness and classic DM suggest s that there is a continuum from amyopathic to classic DM. However, DM without muscle weakness is a clinical entity with respect to favorabl e long-term prognosis. Unless frank muscle weakness develops, treatmen t with systemic corticosteroids can be avoided.