A 45-year-old woman presents to the clinic complaining of progressive muscle weakness and a new skin rash over the past 2 months. She states she has had difficulty rising from a chair and brushing her hair. She also noticed a reddish-purple rash on her upper eyelids, which she initially attributed to a new makeup product, and a similar rash on her knuckles. She reports feeling generally fatigued but denies fever, joint pain, or swallowing difficulties. Her past medical history is unremarkable, and she takes no regular medications. Her family history is non-contributory. She is a non-smoker and occasionally drinks alcohol.

She is in no acute distress. She is afebrile. Her blood pressure is 120/78 mmHg with a heart rate of 78 bpm and a respiratory rate of 14/min.