Suspected Giant Cell Arteritis

Key Messages

GCA is a vasculitis of large vessels, predominantly affecting cranial arteries. However, it is a systemic illness and vascular involvement might be widespread. Mean age of onset is about 70; it is very rare before 50 years of age.

Rapid clinical evaluation of suspected GCA is required for timely initiation of glucocorticoid (GC) therapy in order to prevent ischemic complications of GCA and to prevent inappropriate GC therapy in those patients who do not have GCA.


Typical Features of Giant Cell Arteritis (GCA)
  1. Aged over 50 years
  2. Severe temporal headache
  3. Jaw/tongue claudication
  4. Scalp tenderness
  5. PMR type symptoms
  6. Visual disturbance (blurred or double vision, loss of vision – transient or persistent, visual field defects)
  7. Systemic features (e.g., fever, weight loss, night sweats)
  8. Raised inflammatory markers such as CRP
Differential Diagnosis
  • Migraine or Cluster headache
  • Herpes zoster / post-herpetic neuralgia
  • Trigeminal neuralgia
  • Intracranial pathology such as base of skull or infiltrative retro orbital lesions
  • Temporomandibular joint pain
  • Ear pathology
  • Intrinsic eye pathology such as acute angle glaucoma
  • Sinusitis
  • Cervical spondylosis


  • CRP
  • FBC
  • U&E
  • LFTs.

Management – When to Refer

STEP 1: Calculate GCA Pre-Test Probability

3Score (Highest only)
Ageaged below 50aged 50 - 60aged 60 -65aged over 65
Onset (Weeks)Over 24 weeks13 - 24 weeks6 - 12 weeksbelow 6 weeks
CRP6 - 1011 - 25Greater than 25
New head/scalp painY
Ischaemic symptomsY
Ophthalmology findings

Temporal artery examtendernessthickeninglost pulse
Cranial Nerve Palsy (III, IV, VIY
Alt diagnosis as/more likely than GCA or atypical ethnic groupY
Total Score

CRP: Use greatest value after onset of symptoms but before steroids started.

Constitutional: One or more of: fever, drenching night sweats, weight loss

PMR: Symptoms of more than 30 minutes morning stiffness shoulder/hip girdle muscles, or any past use of steroids for PMR diagnosis

Ischaemic: Acute blurring of vision confined to one eye only, diplopia, amaurosis fugax, jaw/tongue claudication pain when chewing (not pain on bite / opening jaw).

Ophthalmology findings: Anterior ischaemic optic neuropathy, central retinal artery occlusion, visual field defect, relative afferent pupillary defect. This section can be omitted in a primary care setting and scored as 0.

Likely alternative diagnosis or non-white ethnic group: Score yes if non-white, or any of the following are more likely, or as likely, as GCA to account for current symptoms and signs; active infection, active cancer, other rheumatological condition, other head or neck pathology.

STEP 2: Use total score to guide next management step.

Total Score greater than 13High risk of GCA (>80%). Appropriate for GCA fast-track pathway. See link to flow chart below
Total score 9 – 12Intermediate risk of GCA (25%). Appropriate for GCA fast-track pathway, but alternative causes should still be considered/explored. See link to flow chart below.
Total score lower than 9 and no valid CRP sampleAwait bloods and review diagnosis prior to referral. Withhold steroids prior to blood results, unless ischaemic symptoms present.
Total score lower than 9 with valid CRP sampleNot for GCA pathway, consider alternative causes of headache and if neurology referral would be more appropriate. If rheumatology advice still needed, send advice and guidance request.

*** There have been no confirmed cases to date of GCA in patients with PTPS lower than 9. ***

STEP 3: Using above scoring to navigate referral pathway (follow link below to pathway flowchart).

GCA Referral Pathway Flowchart


Referral Instructions

  • Please call the on-call consultant Rheumatologist or Registrar via Derriford Hospital Switchboard on 01752 202082
  • Where there is ocular involvement, please contact the Royal Eye Infirmary A&E to arrange referral for same day Ophthalmology review in Eye Casualty and simultaneously refer to rheumatology using the above process.

If a patient is referred to Ophthalmology and it is not feasible/easy to do bloods at the surgery, then the GP must request that the Ophthalmologists do them.

Supporting Information

GP Information

There have been no confirmed cases to date of GCA in patients with PTPS lower than 9.

Estimation of the probability of GCA is based on all information available (symptoms, signs, laboratory tests and alternative non-GCA explanations for the clinical picture) and can be updated based on new information (clinical course, result of temporal and axillary ultrasound and/or results of temporal artery biopsy).

Almost all GCA patients with cranial disease are over 60.

GCA is very rare in non-white patients.

Patient Information

Versus Arthritis, GCA patient information


Mackie S, Dejaco S, Appenzeller S et al. British Society for Rheumatology guideline on diagnosis and treatment of giant cell arteritis, Rheumatology, Volume 59, Issue 3, March 2020, Pages e1–e23,

F. Laskou, F. Coath, S.L. Mackie et al. A probability score to aid the diagnosis of suspected giant cell arteritis Clin Exp Rheumatol 2019; 37 (Suppl. 117):


Sebastian A, Tomelleri A, Kayani A, et al. Probability-based algorithm using ultrasound and additional tests for suspected GCA in a fast-track clinic. RMD Open. 2020 Sep;6(3): e001297. doi: 10.1136/rmdopen-2020-001297

Quick V, Hughes M, Mothojakan N, Fishman D. P180 External validation of the Southend GCA Probability Score (GCAPS) as a screening tool for referrals with possible GCA, Rheumatology, Volume 59, Issue Supplement_2, April 2020, keaa111.175,

Andrew R. Melville, Karen Donaldson, James Dale et al. Validation of the Southend giant cell arteritis probability score in a Scottish single-centre fast-track pathway. Rheumatology Advances in Practice 2021; 00:1–9,

Publication date: May 2023

Last updated: 19-05-2023


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