GP Connect Clinical feature by Dr. Cory Lei, MBBS FRACGP CHIA, GP, Clinician Assist WA GP Clinical Editor (WAPHA), Hospital Liaison GP (SCGOPHCG) Dr Krista Makin FRACP, Consultant Rheumatologist, Head of Department – Rheumatology (SCGH)
Giant cell arteritis (GCA) is widely recognised by GPs as a “serious disorder not to be missed.” It is one of the few true rheumatologic emergencies. However, in day‑to‑day general practice, many patients present with symptoms that are readily explained by far more common conditions. The “common things are common” heuristic is usually helpful but in GCA, it can also lead to diagnostic anchoring and delayed recognition.
Beyond the classic presentation
The classic GCA presentation with new temporal headache, scalp tenderness, jaw claudication, and visual symptoms remains important. However, not all patients present this way. The onset of GCA can be insidious, with symptoms evolving over weeks or months. Early features may be non‑specific; fatigue, malaise, low‑grade fever, or myalgia without overt cranial symptoms.
Atypical presentations are not unusual with around 18 per cent of biopsy confirmed cases presenting without classic features,1 and these patients are more likely to experience diagnostic delay.
In practice, GCA may show up as:
- Persistent or evolving headache without classic temporal localisation.
- Facial, sinus, dental or ear pain.
- Constitutional symptoms without a clear source.
- Polymyalgia‑type symptoms without cranial features.
- Repeated presentations with partial or transient response to treatment.
- Diplopia and ocular motor palsy.
Symptoms may unfold gradually, with patients re-presenting over weeks to months. This tempo can falsely reassure clinicians, particularly when symptoms seem to fit a more benign or common diagnosis.
Inflammatory markers – an important clue
While often regarded as tests with limited value, CRP and ESR remain some of the most useful clues for GCA that can be requested in general practice. Most patients with GCA, including those with atypical presentations, have elevated ESR and /or CRP.1
Markedly raised inflammatory markers in a patient over 50 years of age with persistent head, neck, or systemic symptoms should always prompt reconsideration of GCA even if the working diagnosis appears plausible. While there is no specific threshold and GCA can occur at any CRP or ESR level, an ESR > 60 mm/hr without another obvious cause is considered significant.2 CRP (standard-sensitivity) assay levels > 10 mg/L should raise suspicion, and a level > 25 mg/L is highly concerning.
Southend scoring tool
Clinicians may find the Southend GCA Probability Score (SGCAPS)3 helpful in determining the likelihood that someone has GCA. The tool considers the patient’s history, examination findings and CRP. No imaging is required to calculate the score.
While no tool is perfect, a SGCAPS ≥9 has a high degree of sensitivity (>95%)4-6 and should trigger an urgent discussion with your tertiary rheumatology service.
Common mimics and diagnostic traps
GCA may present similarly to common diagnoses including:
- Sinusitis or upper respiratory pathology.
- Tension‑type, migraine or chronic headache.
- Dental or temporomandibular disorders.
- Polymyalgia rheumatica alone.
Consider revisiting GCA if:
- Symptoms persist or evolve despite appropriate management.
- There are repeated presentations without clear resolution.
- Inflammatory markers are disproportionately elevated.
Summary
GCA is not always an acutely dramatic presentation. It may evolve over time and mimic more common conditions. Maintaining a degree of diagnostic flexibility is essential to avoiding delayed diagnosis and preventing complications. The SGCAPS is a highly sensitive tool and may aid your assessment.
If concerned or unsure, contact your local tertiary hospital specialist rheumatology service for advice. Each tertiary hospital service in WA has its own clinical pathway for prompt review of patients presenting with symptoms concerning for GCA. In the event that the service is not available, refer suspected cases urgently to the nearest emergency department for further evaluation.
References:
- Sverdlichenko I et al. Atypical Signs and Symptoms of Giant Cell Arteritis: A Systematic Review. J Gen Intern Med 2024. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC11861792/
- Van der Geest KSM. Diagnostic Accuracy of Symptoms, Physical Signs, and Laboratory Tests for Giant Cell Arteritis. JAMA Internal Medicine 2020. Available from: https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2769372
- Laskou et al. A probability score to aid the diagnosis of suspected giant cell arteritis. Clin and Experimental Rheumatol 2019. Available from: https://www.clinexprheumatol.org/abstract.asp?a=13113
- Mathake et al. Performance of the Southend pre-test probability score (PTPS) for giant cell arteritis in a fast-track clinic in Western Australia. Rheumatol Adv Pract 2022. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC9334783/
- Melville et al. Validation of the Southend giant cell arteritis probability score in a Scottish single-centre fast-track pathway. Rheumatol Adv Pract 2021. Available from: https://pubmed.ncbi.nlm.nih.gov/35059557/
- Okamura-Kho et al. Performance of the Southend Giant Cell Arteritis Probability Score in a Single-Centre New Zealand Fast-Track Pathway. Int J of Rheumatic Dis 2026. Available from: https://onlinelibrary.wiley.com/doi/10.1111/1756-185x.70562