Giant cell arteritis (GCA)

Giant cell arteritis is one of the vasculitides: here the immune system sets upon the wall of an artery, the wall thickens and swells, and the channel inside narrows until whatever lies beyond is short of blood. Under the microscope the inflamed wall is crowded with unusually large immune cells, which is where the name comes from. The arteries over the temples are the classic site, but the aorta and its branches to the neck and arms are involved more often than was once realised, which places GCA within the vasculitis family's large-vessel group.

What sets it off is unknown. It is an autoimmune process, genes seem to matter, and it belongs to later life: GCA is very rare under 50, most common between 60 and 80, seen more often in women, and commoner in people of northern European ancestry than elsewhere. Around 5,000 people a year are diagnosed with it in the UK, which makes it one of the vasculitis family's most frequent members. It is closely tied to polymyalgia rheumatica: up to half of people with GCA have the shoulder and hip stiffness of PMR at some point, and a smaller share of people with PMR go on to develop GCA.

The features that point to GCA are new ones, and most of them are in the head:

• A headache of a kind you have not had before, often over the temples and sometimes elsewhere in the head
• A scalp that is tender to touch, so that combing your hair hurts
• Pain or tiredness in the jaw or tongue when chewing, which builds as you eat rather than starting with the first bite
• Arteries at the temples that look swollen or feel thickened or tender
• Blurred or double vision, or sight that fades in one eye and comes back with none of the other signs of a stroke, which are warnings that the eye's blood supply is under threat and need an eye casualty or urgent eye clinic the same day
• Feeling generally unwell, with tiredness, a low fever, sweats, loss of appetite or weight loss
• The aching stiffness of the shoulders and hips of polymyalgia rheumatica, in up to half of people

Less often there is pain in the arms on using them, from the larger arteries, and rarely the first sign of GCA is sight lost suddenly and completely with no warning at all, a 999 or A&E emergency.

The first pointers are the story and the examination, the arteries at the temples included, together with blood tests: raised inflammatory markers, and often a raised platelet count, are what GCA usually shows. With the eyes at stake, treatment does not wait for confirmation: when GCA is strongly suspected the first dose of steroid is given as soon as the blood has been taken, and the tests that confirm the diagnosis follow within days.

Every suspected case needs a confirming test. The two in use are ultrasound of the arteries at the temples and in the armpits, which shows the swollen artery wall as a halo around the channel, and a biopsy of a temporal artery, a small piece removed under local anaesthetic and examined under the microscope; some people have both. The scan is at its most reliable in the first week of treatment, before the steroid shrinks the halo, so it is arranged quickly. Where the aorta or its branches may be involved, a PET scan, a CT or MRI angiogram, or ultrasound of the arteries under the arms can show it. The referral for this specialist imaging, or for a biopsy where that is the better test, is made by Dr Borukhson without delay, sight being at stake.

Steroids work in GCA, and they work quickly: within days of the first high dose of prednisolone tablets most people feel the headache lift. Where sight is threatened or has been lost even briefly, the first doses may be given into a vein in hospital (methylprednisolone), for up to three days, before the tablets take over. The eyes, and the other arteries under threat, are protected by how quickly that first dose is given.

The high dose is held until the symptoms and the blood markers have settled, then reduced in steps, quickly at first and more slowly as the dose gets low, over twelve to eighteen months in a straightforward course and longer where the inflammation returns. Steroids must never be stopped suddenly, as our steroids in rheumatology guide sets out. A course of this length brings bone protection with it, often a medicine to protect the stomach, checks of blood pressure and blood sugar in the first weeks, and regular monitoring, every few weeks early on and less often as the dose falls.

Two medicines can spare steroid. Tocilizumab, a biologic that blocks the action of a messenger called interleukin-6, is added under specialist supervision where GCA keeps coming back or will not settle, or where the steroid is the greater danger; NHS England pays for it once GCA has returned or failed to settle on steroids, one course of no more than a year, with blood tests after the first month or two and at intervals from then on, and because a serious infection is a risk on it, and interrupts it, its place is weighed for each person. Methotrexate is the older alternative, with more modest evidence behind it. Medicines that block tumour necrosis factor do not work in GCA and are not used. Some people are also given low-dose aspirin to protect against a stroke, a decision made case by case.

The plan is yours: reviewed as the course runs, with the dose adjusted to how the condition behaves.

GCA is best known at the temples, but in many people the inflammation reaches the aorta and the great vessels that feed the neck and arms as well, sometimes with no symptoms to show for it: this is large-vessel GCA, and it puts GCA beside Takayasu arteritis as one of the two large-vessel vasculitides (LVV) described in the vasculitis guide. It turns up on the scans used to investigate the condition, or later, when general symptoms such as weight loss, fever, night sweats, an arm that tires with use, or a new ache in the back or the belly return during the steroid reduction and prompt a scan of the large vessels; a fever on treatment takes the same-day route of the second list under When to seek help, and with the signs of sepsis in the first list it is a 999 or A&E emergency.

The steroid course is the same and settles this inflammation too, but in large-vessel GCA the steroid more often needs a partner, methotrexate or tocilizumab, most of all when the inflammation returns on a falling dose. A wall that has been inflamed can widen slowly over the years, and rarely, over a long course, the widening becomes an aneurysm, a bulge in the wall that can weaken. Your team may therefore keep an eye on the aorta with a scan at intervals through the years of follow-up; how often, and whether at all, is decided for each person. It is a precaution: the widening, where it comes, builds slowly, and the scan is there to find it early.

GCA is a rheumatologist's condition that leans on other specialists: an eye specialist whenever sight is involved, the radiologists who scan the arteries, a surgeon for the biopsy, and vascular or cardiac colleagues where the aorta has been affected. Dr Borukhson practises within a world-renowned tertiary centre, with ready access to consultant colleagues in the other specialties this condition may call on. Where it helps, she can bring those specialists in directly, and particularly complex cases can go to a multidisciplinary team meeting (MDT) with minimal delay. Whenever more than one kind of expertise is needed, the strands of your care can be drawn together and decisions reached promptly.

Treatment is what counts in GCA; your part is to keep the course steady and to notice anything that changes.

• Take prednisolone every day as prescribed, as a single morning dose with breakfast, and never stop it or cut it yourself: keep your steroid card on you and show it to whoever treats you.
• Keep every review, since the checks on your blood, blood pressure, blood sugar and bones are how the steroid's side effects are caught early, and they are also where the pace of the reduction is set.
• Protect your bones: bone protection usually comes with the steroid, calcium and vitamin D or a bone-strengthening medicine, and walking or other weight-bearing activity, as much as you can manage, adds to it.
• Eat well and keep moving, since steroids sharpen the appetite, push up weight, blood sugar and blood pressure, and thin the muscles as well as the bones; a walk each day protects more than it seems.
• Take care around measles, chickenpox and shingles: keep away from anyone with any of them, above all if you have never had measles or chickenpox, and if contact happens, seek advice that day from your GP, your rheumatology team or NHS 111, whether or not you have had the illness before, since on steroids, methotrexate or tocilizumab these infections can be severe, and if you are on steroids, a medicine to protect you may be needed.

Most people come through well: the course runs long, the dose comes down slowly, and tiredness and low days along the way are part of it rather than a sign of failure; a low mood that is hard to cope with is worth telling your GP or the team, and the lists under When to seek help below cover a marked change in mood and any thought of self-harm. Vaccinations are worth raising early, since live vaccines cannot be given on a high steroid dose.

Sight is the reason this section exists: a change in it cannot wait, and nor can the other signs below, while the rest of a GCA course can wait for the next review.

Treat any of these as a 999 or A&E emergency: call 999 and do not drive yourself to A&E.

• Severe illness with suspected sepsis: a high fever with shaking, confusion, rapid breathing, or feeling dramatically worse over hours
• With a fever or feeling unwell, a rash that does not fade when you press it, a stiff neck with eyes that cannot bear bright light, or skin, lips or tongue turning blue, grey, pale or blotchy, since these can be signs of meningitis or sepsis; on black or brown skin the rash and the change of colour may be easier to see on the palms of the hands or the soles of the feet
• An eye that suddenly and completely loses its sight, since GCA can cut off the blood supply to the eye, and sight lost this way is usually lost for good
• Sudden weakness or numbness on one side, a drooping face or difficulty speaking, a sudden severe headache, sudden confusion or a seizure, or sudden loss of vision, any of which can be a stroke, even if it stops after a short time, and in GCA an inflamed artery to the brain can block; sight that faded and came back on its own, with none of the other signs, belongs to the second list, for an eye casualty or urgent eye clinic the same day
• Chest pain that is crushing, tight or like a pressure, that spreads to an arm, the jaw, the neck, the stomach or the back, that comes with breathlessness, sweating, feeling sick or feeling light-headed, or that came on suddenly and does not go away
• Breathlessness that is severe, with gasping, choking or no breath to get words out; or coughing up blood
• Palpitations happening now that do not stop, or that come with chest pain, breathlessness, feeling faint or fainting, since a heart whose muscle or rhythm is affected has to be checked at once
• A blackout, since in GCA the heart's own supply, and the arteries to the head, can be affected
• Sudden severe pain in the abdomen or back, since the wall of an inflamed aorta can split or give way
• An arm or leg that has suddenly gone cold, pale, numb or very painful and stays so, since in large-vessel GCA an artery to the limb can narrow and block
• Lips, mouth, throat or tongue that suddenly swell, a throat that feels tight, very fast breathing or a struggle to breathe or to swallow, skin, tongue or lips turning blue, grey or pale (on black or brown skin this may be easier to see on the palms of the hands or the soles of the feet), becoming suddenly very confused, drowsy or dizzy, or fainting and not being able to be woken, since this can be a severe allergic reaction, anaphylaxis, which can follow a dose of any medicine
• Vomiting blood, or bleeding from the back passage that is heavy or will not stop, most of all with faintness, confusion or pain in the abdomen, or vomit that is black or dark brown, since a stomach ulcer on prednisolone can bleed
• Thoughts of harming yourself or ending your life, which steroids can bring on

Any of these needs an assessment that is urgent, on the same day, from your GP, your rheumatology team or NHS 111:

• Sight that has blurred, doubled or dimmed, that is lost in part, or that faded and came back, which needs an eye casualty or urgent eye clinic the same day, since these are the warnings that the eye's blood supply is under threat, and treatment given now protects it
• A new headache, a scalp that is tender, or pain in the jaw or tongue when chewing, whether before the diagnosis or returning as the dose comes down, since before diagnosis they mean GCA must be found and treated that same day, and on treatment they mean the arteries have flared and the dose needs raising
• A fever, or feeling generally unwell, on immunosuppressant, biologic or steroid treatment, since an infection has to be treated early
• A joint that is hot and swollen, with a fever or feeling unwell, since an infected joint has to be ruled out at once, at A&E or through NHS 111
• A joint that has become hot and very swollen suddenly, or is worsening quickly, even without a fever, since an infected joint does not always announce itself with one; a joint that will take no weight at all, or that cannot be moved, is a 999 or A&E emergency, whether or not there is a fever
• New chest pain, new palpitations, or breathlessness that is new or getting worse, since the coronary arteries can be involved; palpitations happening now that do not stop, or that come with chest pain, breathlessness, feeling faint or fainting, belong to the first list
• A marked change in mood or behaviour, confusion, or seeing or hearing things that are not there, on steroid treatment, since prednisolone can do this, the more so the higher the dose; confusion that comes on suddenly is a 999 or A&E emergency, as the first list says
• Unusual thirst or hunger, passing urine more often, or feeling sleepy or confused, on steroids, or swelling of the arms or legs, bruising or bleeding that is not normal, black or dark red stools, severe stomach pain, severe back pain, a severe upset stomach, being sick, or very bad dizziness, since each can be a steroid effect that needs checking without delay; pain in the abdomen or back that comes on suddenly and severely is a 999 or A&E emergency, as the first list says
• Contact with measles, chickenpox or shingles, since these infections can be severe on steroids and a medicine to protect you may be needed
• Being near someone with measles, chickenpox or shingles, while you take a medicine that weakens the immune system, since measles and chickenpox can be dangerous when the immune system is weakened, and you can catch chickenpox from someone with shingles if you have never had chickenpox; NHS 111 can tell you what to do that day

Report to your team promptly, rather than holding it for a booked appointment: tiredness, night sweats, a loss of appetite or weight, or the shoulder and hip stiffness of polymyalgia creeping back on a falling dose; an arm or a leg that aches with use; or an ache in the back or the belly that is new but not severe, for any of these can be the larger arteries flaring, which is what a scan of the large vessels looks for.

Other side effects of the steroid that trouble you are for your GP, your pharmacist or the team, without waiting for a review; everything else about a quiet course waits for the planned appointments. If you cannot tell how urgent something is, asking is never a mistake.

In GCA, delay costs sight. Nearly all the sight lost to it goes before treatment starts or in its first days, and once lost it seldom returns, which is why the first dose is given on suspicion and the tests follow. If you are over 50 with a new headache, a tender scalp or pain when you chew, act on the day you notice it: sight lost suddenly and completely is a 999 or A&E emergency; for a change of any other kind in what you see, with none of the other signs of a stroke, an eye casualty or urgent eye clinic the same day; and with sight unchanged it is an urgent GP appointment or NHS 111 the same day, though a headache that comes on suddenly and severely is a 999 or A&E emergency, as the first list under When to seek help says. A specialist review then settles the diagnosis and sets the course.

How fast must suspected GCA be seen?

The same day. GCA is handled as an emergency, and sight lost suddenly and completely is a 999 or A&E emergency. Call 999 and do not drive yourself to A&E. Treatment begins as soon as the condition is strongly suspected, and specialist assessment follows on the same working day where that can be arranged, and within three working days at most. Any other change in your sight, even one that passed with none of the other signs of a stroke, is looked at the same day at an eye casualty or urgent eye clinic, since sight that GCA has taken outright seldom comes back, and nearly all of it goes before treatment starts or in its first days; a change that passed with any of the other signs of a stroke belongs to the first list under When to seek help. A headache you have not had before, a tender scalp or jaw pain on chewing, even on its own, still belongs with your GP or NHS 111 the same day, though a headache that comes on suddenly and severely is a 999 or A&E emergency, as the first list under When to seek help says.

Does treatment start before the results are back?

Yes. Since sight is what is at risk, a high dose of steroid is given as soon as GCA is strongly suspected, before confirmation. Blood is taken first, or straight afterwards, since the markers of inflammation fall once treatment starts. Confirmation follows within days: ultrasound of the arteries at the temples and in the armpits, a biopsy of a temporal artery, or both. The scan is done quickly, within the first week of treatment where possible, since the steroid soon quietens the changes it looks for.

How long will I be on steroids?

Usually a year or two, sometimes longer. The course opens with a high dose of prednisolone to bring the inflammation under control, then comes down in steps under regular review, more slowly the lower it gets. Symptoms return in about half of people at some point, most often within the first eighteen months, and the answer is to raise the dose again for a while rather than to stop. A steroid is never stopped abruptly. Over a course this long your bones are usually protected, your stomach may be protected too, and blood pressure and blood sugar are watched, all of it planned with you.

Where does tocilizumab fit in?

Tocilizumab is a biologic medicine that blocks the action of a messenger called interleukin-6, injected under the skin alongside the steroid so the dose can fall sooner. In England it is funded for GCA that has come back or has not responded to steroids, for a single course of up to a year. It is not started while an infection is active, and because it can blunt the fever and the blood markers that would normally reveal one, infections are watched for on it; whether it belongs in your plan is a decision made with you as the course goes on. Methotrexate is the other medicine sometimes used to spare steroid.

Does GCA reach arteries beyond the head?

Often, yes. In many people GCA takes in the aorta, the great artery from the heart, and its branches to the neck and arms as well as the temples; this is large-vessel GCA, the form of large-vessel vasculitis (LVV) that starts after 50. It may cause no symptoms at all and turn up only on the scans that investigate the condition, or show as general symptoms: weight loss, night sweats, an arm that tires with use. The same steroid course settles it, though a second medicine, methotrexate or tocilizumab, is needed more often when the large vessels are involved. Over years, a wall that was inflamed can slowly widen, and rarely, after a long course, an aneurysm forms, which is why the aorta may be checked by scan at intervals. A scan booked this way is routine caution, not a signal of trouble.

What needs help straight away?

Losing the sight of an eye suddenly and completely is a 999 or A&E emergency. Call 999 and do not drive yourself to A&E. Any other change in how you see, including blurring, double vision, part of your sight gone or sight that faded and then returned with none of the other signs of a stroke, needs an eye casualty or urgent eye clinic the same day. A headache you have not had before, a scalp tender to the touch or pain in the jaw as you chew is for an urgent GP appointment or NHS 111 the same day, even on its own, though a headache that comes on suddenly and severely is a 999 or A&E emergency, as the first list under When to seek help says. The lists under When to seek help above have the full set, including the signs of infection to watch for on treatment.