What is amyopathic DM?
Occasionally, the cutaneous manifestations of DM occur in the absence of clinically apparent muscle involvement, which is referred to as CADM. Perhaps half or more of such patients will develop muscle disease over time, but a significant proportion will manifest skin-limited disease only (anti-SAE). This form can be associated with malignancy (anti-TIF-1γ, anti-NXP2), whereas other patients may develop extramuscular manifestations such as rapidly progressive ILD (anti-MDA-5/CADM-140) even in the absence of myositis.
