How do you counsel young adults with antibody-negative necrotizing myopathy on prognosis and long-term monitoring/treatment?

The first step is to rule out other conditions that are associated with necrotizing myopathy, that can affect treatment and prognosis, like malignancy, thyroid disease, or genetic muscle diseases. History, physical exam, basic laboratory work-up, family history, age-appropriate malignancy screening, and panCT can aid with that.

The next step is to establish that is a case of true "antibody-negative immune-mediated necrotizing myopathy (IMNM)". While anti-HMGCR and anti-SRP are the most common an...