Ease Into Prep with a USMLE^® Step 2 CK Question of the Day

The correct answer is A. This patient has signs and symptoms of giant cell arteritis (GCA), also known as temporal arteritis. It is a progressive inflammatory disorder that affects large cranial arteries. Common symptoms include unilateral headache, jaw claudication (pain with chewing), and amaurosis fugax (transient ischemic attack of the retina).

Giant cell arteritis is more common in individuals who have polymyalgia rheumatica (PMR). The initial workup of temporal arteritis should include an erythrocyte sedimentation rate (ESR); an elevated ESR (>100 mm/hr) in the presence of clinical symptoms is virtually diagnostic of GCA. Laboratory studies may also reveal elevated C-reactive protein or anemia of chronic disease. Approximately 15 to 20% of patients who have untreated GCA develop blindness from involvement of the ophthalmic artery and/or its branches.

In the presence of an elevated ESR and acute symptoms, including visual changes, immediate high-dose prednisone (choice B) or IV methylprednisolone should be initiated. It is essential to begin treatment with glucocorticoids immediately to prevent this complication. However, since high-dose steroids can be associated with multiple toxicities, treatment should generally not be started based on symptoms alone.

MRA (choice C) is useful for studying carotid circulation, but is not necessary to diagnose or to treat this condition. Waiting for an MRA is an unnecessary and dangerous delay.

NSAIDs (choice D) are an adjunct treatment used to facilitate tapering of steroids and help control pain. They do not provide adequate anti-inflammatory effects to be considered first-line therapy.

Temporal artery biopsy (choice E) is the gold standard diagnosis, but it may be deferred in those who have acute, threatening symptoms. If there is no improvement in symptoms in 72 hours, the diagnosis should be revisited. Patients who respond to glucocorticoids will need to be tapered and kept on low-dose maintenance therapy for at least 1 year, with monitoring of the ESR to gauge response.