If you have PMR, you could also have GCA

In the third post of our GCA Awareness campaign, I Wish I’d Known, we’re raising awareness of the overlap between PMR and GCA.

If you’ve been diagnosed with Polymyalgia Rheumatica (PMR), steroids often bring dramatic relief within days. But for some people, that improvement doesn’t come, or it comes and then slips away, or something about the picture doesn’t quite fit. If that’s you, it’s worth asking: could this also be GCA?

Two conditions, closely linked

Giant Cell Arteritis (GCA) and PMR are closely related inflammatory conditions, and they overlap more than people realise. Clinical guidance suggests GCA complicates around 5–10% of PMR cases. Beyond that, a number of studies using advanced vascular imaging have found signs of “subclinical” or hidden GCA in patients whose PMR looks otherwise typical. There are estimates this could be in the region of 20–30%, and some individual studies report even higher. This is exactly why it matters to keep GCA in mind even when nothing seems obviously wrong, and why it’s worth raising with your GP if your PMR isn’t behaving as expected.

When to ask about a rheumatology referral

Talk to your GP about a referral to a rheumatologist if your PMR is:

Not responding to steroids in the way it should
Showing non-typical symptoms that don’t quite fit the usual PMR pattern
Difficult to treat: for example needing unusually high or long-term doses
Relapsing as you try to reduce your steroid dose

Guidance for clinicians notes that when PMR symptoms don’t respond to low-dose steroid treatment, patients should be assessed for an alternative diagnosis, which includes GCA as well as conditions such as rheumatoid arthritis or osteoarthritis. A rheumatologist can help work out what’s really happening and make sure your treatment fits your actual diagnosis.

The symptoms you should never wait on

Some GCA symptoms need same-day medical attention. If you experience any of the following, see a doctor immediately:

A new or unusual sensation in your head
Jaw pain when eating (jaw claudication)
Sudden visual disturbances – blurred or dim vision, loss of sight, or double vision – even if they only last a few minutes. For this one, if you can’t see your doctor, go to A&E

GCA-related sight symptoms usually start in one eye but can move to affect both, which is part of why speed matters.
Undiagnosed and untreated GCA can sometimes lead to permanent sight loss or stroke. It’s treatable, but only if it’s caught in time.

The bottom line

If you have PMR, it’s important to keep GCA on your radar. If your treatment isn’t working as expected, don’t wait for your next routine appointment to mention it. If you notice any of the urgent symptoms above, don’t wait at all.
If you’re symptoms aren’t urgent and you’d like to talk to someone, you can call our telephone helpline or ask a question on our online forum.