Clinically amyopathic dermatomyositis: analysis of a monocentric cohort

Clinically amyopathic dermatomyositis (CADM) is characterized by the presence of specific cutaneous manifestations of dermatomyositis (DM) without clinical signs of muscular involvement. The aim of this study was to examine the prevalence, clinical characteristics, and outcome of patients with CADM followed at our Rheumatology Unit.

Clinical charts of patients diagnosed as DM were retrospectively examined. Epidemiological, clinical, laboratory, instrumental, and histological features of the patients at the time of diagnosis were collected. CADM was diagnosed in the presence of DM-like rash without muscular involvement.

A total of 103 DM patients were identified, of these, 8 were diagnosed with CADM. Six of patients with CADM had subclinical muscle involvement, and were therefore classifiable as hypomyopathic DM.

In our case series, CADM represents 7.7% of the total DM. However, if investigated with instrumental methods, most patients with CADM result to have subclinical muscular involvement.