A 78-year-old woman comes to the office due to muscle pain. For the last 3 weeks, she has had abrupt-onset achy pain and morning stiffness in the shoulders and hips. Associated symptoms include fatigue and low-grade fever, but the patient has had no headache, swelling in the joints, or other new symptoms. Medical history is unremarkable. Physical examination shows increased pain with active abduction at the shoulders and inability to abduct the humerus above horizontal. Motor strength and deep tendon reflexes are normal and symmetric. Laboratory results show a markedly elevated erythrocyte sedimentation rate. Within 1 week, the patient has rapid and complete response to low-dose oral glucocorticoid therapy. Which of the following additional studies is needed to confirm the diagnosis?

Question

A 78-year-old woman comes to the office due to muscle pain.  For the last 3 weeks, she has had abrupt-onset achy pain and morning stiffness in the shoulders and hips.  Associated symptoms include fatigue and low-grade fever, but the patient has had no headache, swelling in the joints, or other new symptoms.  Medical history is unremarkable.  Physical examination shows increased pain with active abduction at the shoulders and inability to abduct the humerus above horizontal.  Motor strength and deep tendon reflexes are normal and symmetric.  Laboratory results show a markedly elevated erythrocyte sedimentation rate.  Within 1 week, the patient has rapid and complete response to low-dose oral glucocorticoid therapy.  Which of the following additional studies is needed to confirm the diagnosis?

Quizplus · Accepted Answer

11ec25c8_d123_20fb_bc81_b7e8f03c02bb_MD0003_00 This patient has acute, aching pain and stiffness in the shoulders and hips, findings consistent with polymyalgia rheumatica (PMR). Although the term "polymyalgia" implies a myopathic process, PMR is an inflammatory disorder of the proximal joints, bursae, and tendons; the muscle itself is unaffected and strength remains normal. Morning stiffness, gelling (stiffness with inactivity), aching pain, and limited range of motion (eg, shoulder abduction >90 degrees) of the shoulders, hips, and/or neck are common findings. Patients also often have systemic symptoms (eg, fatigue, fever, weight loss). PMR occurs almost exclusively in patients age ≥50, and a minority of cases are also associated with giant cell (temporal) arteritis (GCA), which is characterized by localized headache, temporal tenderness, jaw claudication, and visual disturbances. There are no highly specific diagnostic tests for PMR, but acute-phase inflammatory markers (eg, erythrocyte sedimentation rate, C-reactive protein) are very sensitive and, when elevated, are generally adequate indications for initiating treatment. PMR responds rapidly and completely to low-dose glucocorticoid therapy (eg, prednisone 20 mg daily), which helps confirm the diagnosis; persistent symptoms despite oral glucocorticoids should prompt consideration of alternative diagnoses. For an older patient with typical symptoms, elevated inflammatory markers, and a positive response to treatment, no additional testing is required. (Choice A) Cyclic citrullinated peptide antibodies are specific for rheumatoid arthritis, which can cause morning stiffness and systemic symptoms. However, the hands are more commonly affected than the shoulders, and swelling is typically seen at the affected joints. (Choice B) Infective endocarditis can cause body aches with systemic symptoms and elevated acute-phase markers. However, this patient has no significant risk factors (eg, valvular heart disease, intravenous drug use) or embolic manifestations (eg, splinter hemorrhages under the nails) to suggest endocarditis. Echocardiography is not required. (Choices C and E) Myopathies (eg, statin-induced myopathy, polymyositis) can cause proximal muscle pain, but myocyte injury usually results in weakness and tenderness on examination; stiffness is less common. The diagnosis is confirmed with a muscle biopsy and an elevated creatine kinase level. (Choice F) Temporal artery biopsy is indicated for patients with features of GCA with or without PMR. However, most patients with PMR do not develop GCA, and temporal artery biopsy is not indicated for uncomplicated PMR. Educational objective: Polymyalgia rheumatica is an inflammatory disorder that occurs in patients age ≥50; it is characterized by aching pain and stiffness in the hip girdle, shoulders, and/or neck. The diagnosis is suggested by the presence of elevated acute-phase inflammatory markers (eg, erythrocyte sedimentation rate, C-reactive protein), and the condition responds rapidly to low-dose glucocorticoid therapy.

A 78-Year-Old Woman Comes to the Office Due to Muscle