Adults
Suspected inflammatory myopathy (myositis)
Symmetric proximal weakness with a raised CK, or dermatomyositis rash.
What to look for
- Symmetric proximal weakness: trouble rising from a chair, climbing stairs or lifting the arms
- Raised CK. AST, ALT and LDH are also often high, which can be mistaken for liver disease.
- Dermatomyositis skin signs: heliotrope rash, Gottron papules, shawl or V-sign, mechanic's hands, periungual changes
- Dysphagia, dyspnea or cough (ILD), Raynaud's, arthritis
- On or after a statin, with weakness and a high CK that persists after stopping it (possible anti-HMGCR necrotizing myopathy)
What to do
- Send CK, aldolase, AST/ALT, LDH, TSH, CBC, metabolic panel, ESR/CRP, ANA, and a myositis-specific and myositis-associated antibody panel.
- Check an ECG and troponin if there are cardiac symptoms. Get PFTs and HRCT if there are respiratory symptoms.
- Cancer screening is part of the workup, especially in dermatomyositis. It is usually guided by rheumatology using IMACS 2023 risk stratification.
- Dysphagia, breathing weakness, rapidly progressive ILD or myocarditis are emergent.
About this urgency level
Early specialist assessment changes outcomes. Send the usual workup with the referral, but don't hold the referral while waiting for results.
Timeframes are typical targets. Local pathways, capacity and clinical judgment come first.