5th August 2024

Giant cell arteritis (GCA)

GCA is a vasculitis which affects medium and large vessels, especially branches of the external carotid artery. It is more common in those aged over 50 years.

Symptoms include headache, scalp tenderness, jaw claudication, fever and loss of vision. It is also commonly associated with polymyalgia rheumatica. In severe cases, patients can develop permanent loss of vision.

Blood tests will show raised CRP and ESR. Diagnosis is confirmed with vascular ultrasonography and/or temporal artery biopsy, however temporal biopsy has been shown to give a high number of false negative results.  The ultrasound finding which is most suggestive of  GCA is a circumferential hypoechoic vessel wall thickening which does not disappear on compression. This is known as the halo sign.

Treatment is with high-dose steroids, which should be started on suspicion of the diagnosis, rather than awaiting a temporal artery biopsy.