Adults
Checkpoint inhibitor rheumatic adverse events (irAEs)
Inflammatory arthritis, PMR-like illness, myositis or sicca during or after anti-PD-1/PD-L1/CTLA-4 therapy.
What to look for
- Inflammatory arthritis (RA-like, oligoarticular, or reactive-like). RF and anti-CCP are usually negative.
- PMR-like illness, sicca, or vasculitis
- Myositis, which can overlap with myocarditis and myasthenia (weakness, ptosis, dysphagia, dyspnea, troponin rise)
- These often persist after the checkpoint inhibitor stops, unlike many other irAEs
What to do
- Refer promptly and coordinate with oncology. Don't assume musculoskeletal symptoms come from the cancer.
- Send CBC, metabolic panel, CRP/ESR, CK, RF, anti-CCP and ANA. Add troponin and ECG if there is weakness or any cardiac symptom.
- Suspected myositis or myocarditis is emergent.
- Steroid-sparing DMARDs are often needed, chosen with the oncology team.
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.