Amyopathic juvenile dermatomyositis (Q92502)

Juvenile-onset amyopathic dermatomyositis is an uncommon variant of juvenile-onset dermatomyositis (JDM), characterised by the hallmark cutaneous features of dermatomyositis for at least 6 months without clinical or laboratory evidence of muscle disease. Cutaneous calcinosis, vasculopathy, and interstitial lung disease frequently complicate the course of classic JDM, but are infrequent in amyopathic JDM. Approximately 75% of amyopathic JDM patients will remain free from muscle disease after years of follow-up, while approximately 25% of patients will evolve to having classic JDM.