Diagnostic workup of GCA in individuals with PMR

Bhaskar Dasgupta, MB, BS, MD, is a consultant rheumatologist and head of rheumatology at Southend University Hospital, UK. He developed guidelines on polymyalgia rheumatica, giant cell arteritis, and the concept of point-of-care rheumatology ultrasound.

Which diagnostic approach would be the most useful and proper to detect subclinical giant cell arteritis (GCA) in a patient with polymyalgia rheumatica (PMR) to avoid relapse after discontinuing or tapering glucocorticoids?

That’s a very interesting question. We particularly suspect subclinical vasculitis in patients who have relapsing PMR or who have other features that would suggest vasculitis, for example, the presence of constitutional symptoms such as fever, night sweats, weight loss; such as persistently raised inflammatory markers; such as nonresponse or partial response to corticosteroids; or features such as upper limb claudication. In these patients we definitely do a search for subclinical vasculitis, or even clinical vasculitis, and the best way we do it is with point-of-care ultrasound (POCUS).

When these patients come up to our rheumatology clinic, then and there we do ultrasound assessment of their arteries and commonly what we do is we look at the axillary arteries, we look at the subclavian arteries, the carotid arteries, as well as the head and neck: we look at the temporal arteries and the frontal and parietal branches.

If this is suggestive of large-vessel vasculitis, we would often do an additional investigation, particularly a positron emission tomography (PET)/computed tomography (CT), because that would then pick up the aortitis that many of these patients have, which we can’t pick up on ultrasound. And often, regularly in these patients, we do echocardiography. Echocardiography gives us dimensions of the ascending aorta, of the arch of the aorta, and the descending aorta. These are the investigations that we regularly do for subclinical or clinical vasculitis in patients with PMR.