Giant cell arteritis (GCA)


Giant cell arteritis (GCA) definition: Most common systemic inflammatory vasculitis in older adults with systemic, neurologic, and ophthalmic complications frequently seen. Involves large and medium sized vessels, particularly those coming off aorta: subclavian, axillary, vertebral, temporal, ophthalmic. Manifestations depend on vessels involved/damaged. Diagnosis = clinical = systemic sx + signs/sx of inflammation large vessels. Remember: Systemic sx will not be subtle e.g. extreme fatigue!


GCA versus Temporal Arteritis: Often used interchangeably, but GCA is a broad category and does not always involve the temporal artery!


Erythrocyte Sedimentation rate (ESR or sed rate): Value often >100. Over 100 is very remarkable w/differential diagnosis = vasculitis vs infection vs malignancy. ESR usually at least over 50 in GCA, but normal values increase w/age. To correct ESR for patient’s age = (age/2) +10 for women and age/2 for men. E.g. 80 yo ESR cutoff = 80/2 + 10 = 50 or above if female OR 80/2 = 40 or above if male.


GCA can present variably: On one hand, classic temporal arteritis: jaw claudication, headaches, vision changes, etc. Others have just systemic complaints- anemia, thrombocytosis, transaminitis, feeling terrible.


Jaw claudication: pain that worsens as patient chews, not just pain when patient chews. Consider the “Chewing gum test”: Reported in literature (NEJM), but not routinely used. Jaw claudication elicited after 2-3 minutes of gum chewing.


Role of temporal artery biopsy: Dr. Sharim recommends. Sufficient segment (at least 1-2 cm) is required due to skip lesions. Biopsy identifies 85 to 95% of cases (Cornelia NEJM 2014). Nice to be confident of diagnosis, given the morbidity of the steroid treatment once you commit. Biopsies remain positive at least one to two weeks, up to a month after initiating steroids, so don’t worry about initiating steroids prior to biopsy.


Treatment of GCA: Prednisone 60 mg per day or 1 mg/kg/day, followed by long slow taper over 1-3 years. Start steroids if concern. Can always stop them, but urgent rheumatology referral (w/in 24 hours) required +/- prompt ophthalmology referral depending on presence/absence of visual symptoms.  


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