Giant-cell Arteritis (GCA) or Temporal Arteritis
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Contents Disclaimer ...... 1 Red Flags ...... 2 Background – About Giant-cell Arteritis (GCA) or Temporal Arteritis ...... 2 Assessment ...... 2 Management ...... 4 Referral ...... 6 Information ...... 7 For health professionals ...... 7 For patients ...... 7 Disclaimer ...... 7
South Eastern Melbourne PHN Giant-cell Arteritis (GCA) or Temporal Arteritis pathway 1 Red Flags
• Vision loss
• New onset or new type of headache in a patient aged > 50 years
Background – About Giant-cell Arteritis (GCA) or Temporal Arteritis
GCA is an immune-mediated, ischaemic condition caused by inflammation in the wall of medium to large arteries. The temporal artery is usually the only artery in which physical changes are clinically apparent, although other large arteries can be involved. Hence, the alternative name of temporal arteritis. • Usually affects people aged > 50 years, is most prevalent in Caucasians, and is 2 to 3 times more common in females than males. • 40 to 50% of patients with GCA have concurrent polymyalgia rheumatica (PMR). About 15% of people with PMR will develop GCA. • Large-vessel stenosis occurs in 10 to 15% of patients. The risk of aortic aneurysm is 17 times greater, even after timely and successful treatment. • Temporal artery biopsy is essential to diagnosis. • Treatment: o Must be treated urgently due to the significant risk of permanent vision loss. o Prompt treatment with corticosteroids decreases the risk of vision loss from 20% to 1%.
Assessment
1. Assess presenting symptoms – these can be varied and non-specific.
Presenting symptoms • Headache is the most common presenting symptom and may be seen in up to 90% of cases. o Generally presents as a new headache in the temporal or occipital area. o May be associated with scalp tenderness. o Can be worse at night. o May be progressively severe or waxing and waning.
• Other typical symptoms: o Visual disturbances (e.g., blurred vision, diplopia, amaurosis fugax) – these are of critical importance. Sudden blindness may present without any or only minimal preceding symptoms. o Jaw claudication when eating or talking – occurs in up to 50% of patients. o Scalp tenderness, especially when combing hair or resting on a pillow. o Chest pain (rare) o Systemic features (e.g., low-grade fever, anorexia, and fatigue) – occur in about 50% of patients.
South Eastern Melbourne PHN Giant-cell Arteritis (GCA) or Temporal Arteritis pathway 2 2. Consider giant-cell arteritis in all patients aged > 50 who present with a new onset or a new type of headache.
3. Examine the patient:
➢ Perform eye examination looking for signs of optic nerve involvement. A normal eye examination does not exclude GCA.
Signs of optic nerve involvement • Visual acuity – reduced and not correctable with a pinhole
Visual acuity 1. Ask if the patient has distance glasses with them, and if either eye has had known poor vision i.e., a lazy eye. 2. Test their distance vision in each eye, while wearing glasses, using a 3 or 4 m chart. 3. Check each eye separately, with distance glasses if worn. 4. If acuity is subnormal, check with a pinhole. 5. If vision improves with a pinhole, and no cataract is present, then the patient requires a review of their glasses. 6. If unable to read any letters on chart, assess the following in descending order: o Finger counting o Hand movements o Light perception 7. Test near vision while patient is wearing reading glasses.
• Visual fields to confrontation – visual field defect • Pupillary light reaction – sluggish or absent • Swinging light reflex – relative afferent pupillary defect (the patient's affected pupil fails to contract when the light is swung from the unaffected eye to the affected eye, giving the impression of the pupil dilating in response to light) • Fundoscopy (optic disc and retinal vasculature) – swelling or pallor of the optic disc with associated haemorrhage
➢ Check vascular system (including temporal arteries).
Vascular system examination Check: • blood pressure in both arms. • for bruits (carotid, supraclavicular, abdominal, femoral). • for heart murmurs (some patients with GCA may present with aortic aneurysm and aortic valve dilation). • temporal arteries: o May be tender, thickened, hardened, nodular, or have reduced or absent pulses. o A clinically normal temporal artery does not exclude temporal arteritis.
4. Consider associated polymyalgia rheumatica (PMR) and differential diagnoses.
Differential diagnoses • Migraine • Herpes zoster • Temporomandibular joint disorder
South Eastern Melbourne PHN Giant-cell Arteritis (GCA) or Temporal Arteritis pathway 3 • Transient ischaemic attack (TIA) • Other causes of acute vision loss • Intracranial haemorrhage
5. If patient has visual loss or a recent history of transient visual loss, refer directly to the emergency department for further investigation and immediate management (see below).
6. If no current visual loss or recent history of transient visual loss, arrange investigations:
➢ Urgent temporal artery biopsy. Contact a vascular surgeon, general surgeon, or ophthalmologist to arrange. Do not delay initiation of treatment while awaiting temporal artery biopsy (see below).
Temporal artery biopsy • Temporal artery biopsy is highly specific for GCA but false negatives are not uncommon as GCA may be present in "skip lesions" and the segment sampled may be spared. • Adequate sampling of the artery is essential to reduce the chance of a false negative result. A least 1 cm length of artery should be sampled. • Do not delay initiating treatment waiting for the temporal artery biopsy to be done. Histological changes will persist for at least a week after steroid therapy is initiated.
➢ FBE and E/LFTs – non-specific mild elevations in white cell count, platelets, and liver enzymes (ALP mainly) may be present. ➢ ESR and CRP: o Either ESR or CRP can be raised in GCA. o A normal ESR and CRP does not rule out GCA.
Management
1. If GCA suspected and patient has visual loss, recent history of transient visual loss, or signs of optic nerve involvement, refer for immediate rheumatology assessment for:
➢ treatment with IV methylprednisolone 0.5 to 1 g IV over 1 hour. Continue daily for 3 days, then switch to oral prednisolone. ➢ temporal artery biopsy.
2. If GCA suspected, without visual loss or recent history of transient visual loss:
➢ start oral steroid therapy immediately, and
Steroid therapy for GCA • Initiate oral prednisolone at 40 to 60 mg a day (in one or two doses). • Do not delay initiation of steroid therapy while waiting for temporal artery biopsy, investigation results or specialist review if GCA is suspected.
➢ contact a vascular surgeon, general surgeon, or ophthalmologist by phone to arrange urgent temporal artery biopsy.
South Eastern Melbourne PHN Giant-cell Arteritis (GCA) or Temporal Arteritis pathway 4 ➢ contact a rheumatology, neurology, or ophthalmology specialist by phone to arrange urgent assessment and consideration of Tocilizumab.
Tocilizumab • Toclizumab is a new novel biologic agent that is very effective in inducing remission and sparing steroid use and consequent steroid related toxicity. • Tocilizumab is an IL6 inhibitor biologic drug that can only be prescribed by a rheumatologist. It is given as a weekly subcutaneous injection. • It is indicated for new onset GCA or for relapse. • There is a legislated requirement for appropriate clinical symptoms, elevated inflammatory markers, and positive temporal artery biopsy (or positive imaging MRA, CTA, or PET scanning, but such imaging is best confined to centres with particular expertise in temporal artery imaging).
➢ prescribe aspirin 100 mg daily (unless contraindicated).
Aspirin • Aspirin has been shown to reduce cranial ischaemic complications of GCA e.g., TIA or stroke. • If aspirin is started, monitor for adverse effects, especially gastrointestinal-related.
➢ discuss with the patient that long-term use of corticosteroids may be necessary, and their possible side-effects:
Side-effects • Increased risk of bacterial infection • Reactivation of latent infection • Accelerated atherosclerosis • Osteoporosis • Psychiatric disturbances (e.g., mania, delirium, and depression) are generally uncommon, unless: o pre-existing mood disturbances o excessive alcohol intake o prednisolone doses > 40 mg • Diabetes – new onset or reduced control of existing • Hypertension • Gastrointestinal ulceration • Weight gain • Skin thinning, easy bruising, delayed wound healing • Insomnia • Muscle weakness
• Give information on oral steroids and sick day advice. See Long-term Corticosteroids.
➢ advise the patient to present immediately to the emergency department if they develop visual loss.
3. Monitor response to treatment and manage medication accordingly:
➢ Review at one week after starting prednisolone (or before if not improving or if worsening). Patients with GCA generally report significant improvement in the first week of treatment. If not improving:
South Eastern Melbourne PHN Giant-cell Arteritis (GCA) or Temporal Arteritis pathway 5 • review diagnosis • seek rheumatology advice, and • consider increasing the dose of prednisolone to 0.75 to 1 mg/kg per day. • do not increase prednisolone dose on the basis of inflammatory markers alone.
➢ If improving, plan prednisolone tapering based on clinical response.
Prednisolone tapering • Continue initial dose of 40 to 60 mg a day for 4 weeks. • If symptoms and inflammatory markers improving: o reduce dose by 10 mg every 2 to 4 weeks to 20 mg a day, then o reduce dose by 2.5 mg every 2 to 4 weeks to 10 mg a day, then o reduce dose by 1 mg every 4 to 8 weeks until medication is stopped.
4. Arrange ongoing clinical review for monitoring for clinical relapse and adverse effects from prednisolone: ➢ Weekly for the first month, then every 1 to 2 months. ➢ Check inflammatory markers if clinically indicated. ➢ Ask the patient to seek immediate medical advice if symptoms recur, if they develop any new symptoms, or if steroid-related adverse side-effects occur.
5. If relapse of symptoms treat accordingly, and seek rheumatology advice: ➢ If GCA-suggestive headache – titrate back up to previous dose. ➢ If jaw claudication or visual symptoms – return to starting dose of 40 to 60 mg a day. ➢ Arrange rheumatology referral for consideration of Tocilizumab.
6. Manage cardiovascular (CV) risk in all patients with GCA, as they have an increased risk of cardiovascular disease – see Cardiovascular Disease Risk Assessment.
7. Arrange regular follow-up and check: ➢ symptom control. ➢ compliance with medications. ➢ medication side-effects. ➢ patients concerns. ➢ compliance with and results of regular pathology for patient on disease-modifying antirheumatic drugs (DMARDs) (some patients with GCA may be treated by the specialist with methotrexate alone or in combination with steroid therapy). ➢ cardiovascular risk factors and symptoms of cardiovascular disease.
Referral
• If GCA suspected and patient has visual loss, recent history of transient visual loss, or signs of optic nerve involvement, refer for immediate rheumatology assessment for: o treatment with IV methylprednisolone 0.5 to 1 g IV over 1 hour. Continue daily for 3 days, then switch to oral prednisolone. o temporal artery biopsy. • If GCA suspected, without visual loss or recent history of transient visual loss: o contact a vascular surgeon, general surgeon, or ophthalmologist by phone to arrange urgent temporal artery biopsy.
South Eastern Melbourne PHN Giant-cell Arteritis (GCA) or Temporal Arteritis pathway 6 o contact a rheumatology, neurology, or ophthalmology specialist by phone to arrange urgent assessment and consideration of Tocilizumab. • Seek rheumatology advice if: o treatment failure. o relapse occurs while tapering prednisolone.
Information
For health professionals
Further information
• Australian Family Physician – Polymyalgia and Giant Cell Arteritis
• Patient – Giant Cell Arteritis
• World Journal of Clinical Cases – Giant Cell Arteritis: Current Treatment and Management
For patients
• Better Health Channel – Eyes: Giant Cell Arteritis • Patient – Temporal Arteritis
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Last updated: June 2020
South Eastern Melbourne PHN Giant-cell Arteritis (GCA) or Temporal Arteritis pathway 7