In our #AMreport @, we discussed a case of giant cell arteritis in a patient presenting with temporal headaches, scalp tenderness, fever and weight loss. Elevations in the ESR (105 in this case)along with clinical presentation made the diagnosis of temporal arteritis quite likely. The patient was started on high dose prednisone and referred for outpatient temporal artery biopsy. Classic features: age >50, ESR>50; scalp tenderness; jaw claudication; weight loss; fever.
Giant cell arteritis: Also referred to as Horton’s disease, affects medium to large vessel arteries transmurally (intima, media & adventitia) with lymphocytes and macrophages ultimately causing luminal narrowing and ischemia. It is the ischemia that is concerning where patients are at increased of blindness due to anterior ischemic neuropathy (AION) from ophthalmic artery involvement .
If you suspect a diagnosis of temporal/ giant cell arteritis, do not wait to confirm diagnosis with a biopsy, treat with prednisone at a dose of (1mg/kg) daily. Biopsy can be arranged after initiation of steroids, as the risk of visual loss is major concern with this disease.
It is often that in medical practice that we highlight the downsides of medications more often than benefits. However it is still important to counsel all of your patients about the side effects of steroids before initiation; both acute and chronic (Table 1).
Additionally, disease such as GCA that require long courses of glucocorticoid therapy should also prompt investigations such as testing for chronic hepatitis B and TB in high risk patients to name a few (Table 2). An often overlooked test is strongyloides. Exposure to supra-physiologic doses of prednisone of any duration can cause a hypeinfection syndrome(~100% mortality) in patients with chronic strongyloides infection, particularly individuals from and travel to endemic areas usually tropical climates.
Take Home points:
- Never delay steroid therapy to confirm diagnosis in patients with suspected giant cell arteritis.
- Counsel patients on the benefits and risks of glucocorticoid therapy by citing the acute and chronic complications.
- If committing patients to a long duration of steroid therapy; screen those at risk for chronic infections(HBV, LTBI & strongyloides) and consider PJP prophylaxis in those getting prednisone ≥ 20 mg for ≥ 4-8 weeks.