Treatment with prednisone, 60 mg/d (or 1 mg/kg/d), is indicated immediately for this patient. She has temporal artery pain and tenderness, along with jaw claudication in the setting of low-grade fever and a very high erythrocyte sedimentation rate. Given her age, these findings are most consistent with giant cell arteritis (GCA). The presence of shoulder and hip symptoms is consistent with polymyalgia rheumatica (PMR), which commonly co-occurs in patients with GCA (approximately 50% of cases). Despite a lack of visual symptoms to date, the patient is at risk of acute and potentially catastrophic visual loss. Immediate treatment is therefore warranted, the standard regimen being prednisone at a dose of 60 mg/d. (In the setting of severe visual loss, high-dose pulse glucocorticoids might be considered.) The addition of low-dose aspirin has been shown in limited studies to further reduce the risk of visual loss in patients with GCA already receiving prednisone and is favored by some experts.

Low-dose prednisone in the range of 10 to 20 mg/d is generally adequate treatment for isolated PMR but has not been shown to adequately treat GCA or to prevent visual complications.

MRI of the head permits the visualization of structures that could potentially be associated with headache and/or visual symptoms, including tumors, hydrocephalus, and/or large aneurysms. However, the presence of jaw claudication, as well as the presence of PMR symptoms, is not consistent with an intracranial lesion.

A temporal artery biopsy should be obtained as rapidly as possible to confirm the GCA diagnosis and to help direct long-term management; however, the histopathology of the disease will still be readable up to 1 to 2 weeks after initiation of treatment, and treatment should not be deferred pending biopsy.