You have selected "GCA not in differential" but the following sight-threatening features are ticked in this assessment:
Before excluding GCA, confirm these features are fully explained by an alternative diagnosis. Proceeding will document GCA as excluded despite recorded visual symptoms.
Step 1 — Presenting features (patients almost always >50)
Select all features present. Visual and ischaemic features carry the highest urgency.
⚠ Sight-threatening / ischaemic
✓
Acute visual loss
Transient or permanent, one or both eyes
✓
Diplopia / double vision
New onset, attributed to GCA
✓
Jaw or tongue claudication
Pain on chewing — high specificity for GCA
✓
Visual disturbance
Colour change, blurring, field defect, amaurosis fugax
Cranial / vascular features
✓
New onset headache
Typically temporal
✓
Scalp tenderness
Including pain on brushing hair
✓
Temporal artery abnormal
Tender, thickened, nodular, reduced pulsation
✓
Neurological features
TIA, stroke, confusion, cognitive change
Systemic / PMR features
✓
PMR features
Shoulder/hip girdle pain & stiffness
✓
Constitutional symptoms
Malaise, fatigue, fever, weight loss, sweats
✓
Already on steroids
Markers may be suppressed — see caveat
Step 2 — Inflammatory markers
⚠ Critical marker caveats — read before interpreting
▶Normal ESR does not exclude GCA. Up to 15% of biopsy-proven GCA cases have a normal ESR — and those patients carry the same risk of sight loss as those with elevated ESR (Myklebust & Gran, 1996).
▶Normal CRP does not exclude GCA. Approximately 10% of GCA patients have both normal ESR and normal CRP at diagnosis. CRP is the more sensitive single marker (sensitivity ~87% vs ~84% for ESR).
▶Plasma viscosity (PV) is the primary marker in NHS Grampian (replacing ESR routinely). PV is unaffected by anaemia or polycythaemia. However, PV and ESR each produce ~13% false negatives independently in biopsy-proven GCA — they are not always equivalent. If PV is normal but clinical suspicion remains high, CRP adds independent information.
▶ESR and CRP can be discordant — an elevated CRP with normal PV/ESR (or vice versa) does not reassure. Clinical features take precedence over any single marker.
▶Steroids suppress markers rapidly. If the patient is already on any corticosteroid, normal markers must not be used to downgrade suspicion. Clinical features dominate entirely.
Plasma viscosity (cP)Normal: <1.72 cP · Raised: ≥1.72 · Significantly raised: ≥1.90 Primary marker in NHS Grampian (BSR: use if ESR unavailable)
CRP (mg/L)Normal: <10 · Raised: 10–49 · Significantly raised: ≥50 Most sensitive single marker. Adequate response defined as CRP ≤10
ESR (mm/hr)Normal varies with age/sex · Significantly raised: ≥80 mm/hr Normal ESR does not exclude GCA
Steroid effect flagged: Patient is already on corticosteroids. All inflammatory markers may be partially or fully suppressed. A normal result in this context cannot be used to downgrade clinical suspicion. Clinical features must carry full diagnostic weight.
All entered markers are within normal range. This does not exclude GCA. Up to 10% of biopsy-proven GCA cases have entirely normal inflammatory markers at diagnosis. If clinical features are present, proceed on clinical grounds and discuss with specialist without delay.
Step 3 — Select your clinical judgement to generate the action plan
BSR 2020 defines "strongly suspected GCA" as: "in the assessing clinician's judgement, GCA is a more likely explanation for the patient's symptoms than any other condition." No score replaces this gate — click the option that best reflects your clinical assessment.
↓Features recorded — click one of the options below to generate your action plan
1Call Ophthalmology now. BSR 2020 strong recommendation: patients with new visual loss or diplopia must be seen by ophthalmology on the same calendar day.
2Start Prednisolone 60mg orally immediately (NHS Grampian). Do not wait for blood results. If IV methylprednisolone is accessible, this is preferred for sight-threatening disease.
4Bloods before or immediately after first dose: FBC, U+Es, CRP, Plasma Viscosity, LFTs. Do not delay treatment waiting for results.
5Do not send this patient home without speaking to a specialist. GCA with visual symptoms is a medical emergency.
6Document fully: all symptoms, signs, date/time of first steroid dose and clinical reasoning.
Out of hours: Rheumatology is unavailable. Ophthalmology on-call must be contacted via hospital switchboard. Start Prednisolone 60mg now. Document start date, start dose, and clinical rationale clearly. Refer to Rheumatology on the next working day.
1Discuss with Rheumatology today. BSR 2020: patients should be evaluated by a specialist ideally on the same working day, and in all cases within 3 working days. Do not send home without this discussion.
2Start Prednisolone 60mg orally if GCA is strongly suspected, before the specialist review. First dose can be given without waiting for blood results. Note date and dose in referral letter.
4Bloods now: FBC, U+Es, CRP, Plasma Viscosity, LFTs. Take before or immediately after first steroid dose.
5Bone prophylaxis if ≥65 years: start Calcium + Vitamin D immediately. Bisphosphonate immediately. DEXA scan will be considered by Rheumatology.
6Safety net: advise patient to return immediately if any visual symptoms develop (blurring, visual loss, diplopia, colour change). This changes the pathway to emergency.
7Document fully: all symptoms, signs, date/time of steroid dose and clinical reasoning. Include in referral.
Out of hours: Rheumatology is unavailable. Start Prednisolone 60mg now, document clearly, and ensure urgent same-day Rheumatology referral first thing on the next working day.
⚠ Possible GCA — do not discharge without plan
GCA possible — same-day specialist discussion still required
1Even where uncertainty exists, do not send the patient home without specialist discussion if GCA remains in the differential. A telephone discussion with Rheumatology today is appropriate.
2Bloods urgently: FBC, U+Es, CRP, Plasma Viscosity, LFTs. Remember: normal markers do not exclude GCA.
3Await specialist advice before initiating steroids in this group — the decision requires specialist input given diagnostic uncertainty.
4Safety net explicitly: advise patient to return immediately if jaw pain develops, any visual symptom arises, or headache worsens. This changes pathway to urgent/emergency.
5Document uncertainty and safety-net advice in the records.
GCA not in differential
GCA excluded on clinical grounds — document and manage alternative diagnosis
1Document clearly in the notes that GCA was considered and excluded, with reasoning.
2Pursue alternative diagnoses actively — see differential list above.
3Safety net: if new headache, jaw pain, visual symptoms, or scalp tenderness develop, patient should return promptly for reassessment.
4In patients with known PMR: maintain a low threshold for reassessment — GCA can emerge during the PMR disease course.
Further management — NHS Grampian
Required bloods (before or immediately after first dose):
FBCU+EsCRPPlasma ViscosityLFTsGlucose / HbA1c if not known diabetic
Bone & gastric prophylaxis:
• Omeprazole 20mg daily (gastric protection — unless contraindicated)
• Calcium + Vitamin D — start immediately if aged ≥65
• Bisphosphonate — start immediately if aged ≥65
• DEXA scan — will be considered by Rheumatology
• Routine aspirin or statins: not indicated unless specified by specialist
Diagnostic investigations (secondary care only):
Temporal artery ultrasound and/or temporal artery biopsy. These can only be arranged by Ophthalmology, Rheumatology or Neurology — not from primary care directly.
Adequate response definition (NHS Grampian):
Complete resolution of symptoms AND CRP ≤10 mg/L
Steroid tapering plan — NHS Grampian:
Week
Prednisolone
1
60 mg
2
45 mg
3
30 mg
4
20 mg
5
15 mg
6
12.5 mg
7
10 mg
8
9 mg
12
8 mg
16
7 mg
20
6 mg
24
5 mg
28
5 mg
32
5 mg
36
5 mg
Week
Prednisolone
1
60 mg
2
45 mg
3
30 mg
4
20 mg
5–8
20 mg
8
15 mg
12
14 mg
16
13 mg
20
12 mg
24
11 mg
28
10 mg
32
9 mg
36
8 mg
Relapse: discuss with or refer to Rheumatology / Vasculitis team. Additional immunosuppression only with specialist input.