Idiopathic Inflammatory Myopathies
Rheumatology · Idiopathic Inflammatory Myopathies 🎯 Practice these cards
IIMs classically present with symmetric ____ muscle weakness without substantial ____, and an almost universally elevated serum ____.
The idiopathic inflammatory myopathies classically present with symmetric proximal muscle weakness without substantial pain or tenderness, plus an almost universally elevated serum creatine kinase (CK) that marks ongoing muscle injury. Weakness usually evolves over weeks to months (IBM progresses over years).
The two pathognomonic skin findings of dermatomyositis are ____ papules and the ____ rash.
Gottron papules (violaceous, slightly scaly papules over the MCP and PIP joints) and the heliotrope rash (violaceous eyelid discoloration, often with periorbital edema) are pathognomonic for dermatomyositis and can allow diagnosis without a muscle biopsy.
Inclusion body myositis characteristically weakens the ____ and wrist flexors and the ____ muscles, is often ____, and ____ to immunosuppression.
IBM affects patients over 50 (men more than women), progresses slowly over years, and characteristically involves the finger/wrist flexors and quadriceps (often asymmetric) with only mildly elevated CK. It does not respond to immunosuppression; treatment is physical/occupational and swallowing therapy.
In DM, anti-____ and anti-NXP-2 antibodies signal increased cancer risk, anti-____ signals rapidly progressive ILD, and anti-____ signals a good prognosis.
In DM: anti-TIF1-γ and anti-NXP-2 mark cancer-associated disease; anti-MDA5 marks amyopathic DM with rapidly progressive ILD (high mortality); anti-Mi-2 marks DM with a good treatment response and low cancer/ILD risk.
Antisynthetase syndrome is driven by anti-aminoacyl-tRNA synthetase antibodies (most commonly anti-____); its dominant prognostic feature is ____ disease.
Antisynthetase syndrome = myositis + interstitial lung disease + nonerosive arthritis + Raynaud phenomenon + mechanic's hands + fever, driven by anti-aminoacyl-tRNA synthetase antibodies (anti-Jo-1 most common). ILD is the dominant prognostic feature; no increased malignancy risk.
Unlike direct statin toxicity, anti-HMGCR necrotizing myopathy does ____ improve with statin discontinuation and requires ____; an often-effective therapy is ____.
Anti-HMGCR immune-mediated necrotizing myopathy causes severe proximal weakness with very high CK. Unlike direct statin toxicity, it does NOT improve when the statin is stopped; it requires immunosuppression (IVIG is often effective), and statins must be avoided.
The cornerstone of IIM therapy is ____; the preferred initial steroid-sparing agents are ____ and ____.
Glucocorticoids (e.g., prednisone up to ~1 mg/kg/day) are the cornerstone of therapy for DM, PM, ASyS, and IMNM; methotrexate and azathioprine are the preferred initial steroid-sparing agents. IBM does not respond to immunosuppression.
Weakness on high-dose prednisone with a ____ CK and no EMG irritability indicates ____ myopathy, whereas a relapse shows a ____ CK.
Worsening weakness on high-dose prednisone with a normal CK, Cushingoid features (moon facies, ecchymoses), and no EMG membrane irritability indicates steroid myopathy (taper). A relapse shows a rising CK and abnormal spontaneous EMG activity (intensify immunosuppression).
The ____ trial established IVIG efficacy in adult DM, leading to FDA approval of ____ for adult DM; IVIG can now be used as ____-line therapy.
The ProDERM randomized trial showed IVIG superior to placebo in adult dermatomyositis (~79% vs ~44% response at 16 weeks), leading to FDA approval of Octagam 10% for adult DM — the first approved DM therapy. IVIG can now be used as first-line therapy in DM.
Tap a card to flip it.