A 62-year-old woman comes to the office due to a 3-month history of progressive muscle weakness. The patient has been having difficulty with activities such as getting out of the car and carrying groceries from the store. She has also developed a rash on her face and hands. The patient has a history of well-controlled hypertension and does not use tobacco, alcohol, or illicit drugs. Vital signs are within normal limits. Physical examination shows weakness of shoulder abduction and hip flexion. Strength of the distal limb muscles and deep tendon reflexes are normal. Skin examination findings are shown in the exhibit. Which of the following is the most appropriate initial treatment for this patient's current condition?

Question

A 62-year-old woman comes to the office due to a 3-month history of progressive muscle weakness.  The patient has been having difficulty with activities such as getting out of the car and carrying groceries from the store.  She has also developed a rash on her face and hands.  The patient has a history of well-controlled hypertension and does not use tobacco, alcohol, or illicit drugs.  Vital signs are within normal limits.  Physical examination shows weakness of shoulder abduction and hip flexion.  Strength of the distal limb muscles and deep tendon reflexes are normal.  Skin examination findings are shown in the exhibit.  Which of the following is the most appropriate initial treatment for this patient's current condition?

Quizplus · Accepted Answer

Dermatomyositis is an autoimmune disorder characterized by: Autoantibodies, including antinuclear antibodies (more sensitive) and anti-Jo-1 antibodies (more specific), are frequently positive. Muscle biopsy confirms the diagnosis and shows perifascicular inflammation and atrophy affecting a contiguous portion of the fascicle and surrounding blood vessels. Initial treatment includes systemic glucocorticoids (eg, prednisone). Dermatomyositis may occur alone or as a paraneoplastic syndrome associated with malignancy (especially adenocarcinoma); affected patients should be evaluated for an underlying occult malignancy. (Choice A) Acetylcholinesterase inhibitors (eg, physostigmine) are used in treatment of myasthenia gravis, which presents with fluctuating and fatigable weakness that primarily involves the ocular, bulbar, and respiratory muscles. The skin is not typically involved. (Choice B) Copper deficiency typically presents with muscle weakness, anemia, and fragile (kinky) hair. Skin hypopigmentation is also common, but rash does not occur. (Choice C) Riluzole is a glutamate inhibitor that is indicated for amyotrophic lateral sclerosis, a progressive neurodegenerative disorder that affects both upper and lower motor nerves. Although proximal muscle weakness may be seen (lower motor neuron dysfunction), upper motor neuron signs (eg, bulbar dysfunction, hyperreflexia) are expected and the disease is not associated with skin rash. (Choice E) Hypothyroid myopathy commonly presents with proximal muscle weakness. However, unlike polymyositis and dermatomyositis, patients usually also have prominent muscle pain and often have other hypothyroid features (eg, weight gain, cold intolerance). Educational objective: Dermatomyositis is characterized by proximal muscle weakness (similar to polymyositis) and dermal manifestations (eg, heliotrope rash, Gottron papules). Laboratory testing shows elevated muscle enzymes (eg, creatine kinase) and autoantibodies (eg, antinuclear, anti-Jo-1). Initial treatment includes systemic glucocorticoids and evaluation for potential underlying malignancy.

A 62-Year-Old Woman Comes to the Office Due to a 3-Month