Arteritis Symptoms and Treatment
Clinical Presentation
Giant cell arteritis (GCA) presents with new-onset persistent localized headache (often temporal), jaw claudication, scalp tenderness, and constitutional symptoms, requiring immediate recognition to prevent permanent vision loss. 1
Cardinal Symptoms
Cranial manifestations:
- New-onset headache in the temporal area with scalp tenderness 2, 1
- Jaw and/or tongue claudication during chewing (positive likelihood ratio 4.90, highly specific) 2, 1
- Visual symptoms including vision loss, which occurs in 14-18% of patients and represents an ophthalmic emergency 3, 4
- Temporal artery abnormalities: tenderness, thickening, or reduced pulsation (positive likelihood ratio 3.14-4.70) 2, 1
Systemic manifestations:
- Constitutional symptoms including fever, fatigue, and anorexia 4, 5
- Polymyalgia rheumatica with musculoskeletal pain 4, 5
- Limb claudication (positive likelihood ratio 6.01) 2
Less common ischemic complications:
- Stroke and cranial nerve palsies 3
- Scalp or tongue necrosis 6, 5
- Large-vessel aneurysms and vascular stenoses 3
- Respiratory involvement with chronic nonproductive cough (occurs in <10% of cases) 3, 7
Laboratory Findings
Inflammatory markers are elevated in >95% of cases: 1
- Erythrocyte sedimentation rate (ESR) typically >40 mm/h; ESR >100 mm/h has positive likelihood ratio 3.11 2, 1, 7
- C-reactive protein (CRP) elevated in most cases; absence of CRP ≥2.5 mg/dL has negative likelihood ratio 0.38 (helpful for ruling out disease) 2, 1
- Platelet count >400 × 10³/μL (positive likelihood ratio 3.75) 2, 1, 3
Important caveat: No single clinical or laboratory feature alone is sufficient to confirm or exclude GCA; combinations of symptoms guide further investigation 2
Diagnostic Approach
Patients with suspected GCA require urgent referral within 24 hours to reduce permanent visual impairment. 1
Diagnostic testing includes:
- Temporal artery biopsy with specimen length >1 cm for confirmatory testing (highly specific but imperfect sensitivity) 1
- Vascular imaging (ultrasound, MRI, PET, CT) to identify large vessel involvement 2, 1
- Baseline complete blood count and liver function tests before treatment initiation 8
Do not delay treatment while awaiting biopsy results if clinical suspicion is high. 1
Treatment
Immediate Glucocorticoid Therapy
High-dose glucocorticoid therapy (40-60 mg/day prednisone-equivalent) must be initiated immediately upon clinical suspicion to prevent permanent vision loss. 1
Tapering schedule: 1
- Reduce to 15-20 mg/day within 2-3 months once disease is controlled
- Target dose ≤5 mg/day after 1 year
Glucocorticoid-Sparing Agents
Tocilizumab is FDA-approved for GCA treatment and demonstrates efficacy in reducing glucocorticoid requirements and flare rates. 2, 1, 7, 8
- Tocilizumab dosing for GCA: 162 mg subcutaneously every week or every other week based on weight and clinical response 8
- The American College of Rheumatology supports use of glucocorticoid-sparing immunosuppressive agents 2
Important safety consideration: Tocilizumab increases risk of serious infections including tuberculosis, invasive fungal infections, and opportunistic infections; test for latent tuberculosis before initiating therapy 8
Monitoring
Essential monitoring parameters include: 1
- Regular assessment for clinical signs and symptoms of active disease
- Serial ESR and CRP measurements
- Surveillance for glucocorticoid-related adverse effects
- Monitoring for infection risk with immunosuppressive therapy 8
Laboratory thresholds for treatment initiation: Do not start tocilizumab if absolute neutrophil count <2000/mm³, platelet count <100,000/mm³, or ALT/AST >1.5 times upper limit of normal 8
Takayasu Arteritis Considerations
For Takayasu arteritis (TAK), use nonglucocorticoid immunosuppressive agents combined with glucocorticoids as initial therapy. 2