Typically, in best-case scenarios, you can treat dermatomyositis with IVIG for 1 year, but some patients require it for 18-24 months, and the minority of patients continue to require it over several years. Some patients may only need it until you achieve improvement, especially in some countries whe...

I have several patients who have been refractory to all other immunosuppressants or have had deadly infectious complications that prevent them from tapering off IVIG. This is a small minority, but there are patients who may require for many years.

In my experience, I have needed IVig for MDA 5 DM for more than 2 years and for Statin induced autoimmune necrotizing myositis for more than 2 years.