What is temporal arteritis and its symptoms?

Temporal Arteritis: Definition and Symptoms

Temporal arteritis, also known as giant cell arteritis (GCA), is a systemic vasculitis affecting large and medium-sized vessels, primarily the cranial branches of the aorta, characterized by headache, scalp tenderness, jaw claudication, and risk of permanent vision loss if left untreated.

Definition and Epidemiology

Temporal arteritis is the most common form of primary systemic vasculitis in adults 1. It predominantly affects:

• Individuals over 50 years of age
• Women more than men (3:2 ratio)
• People of Northern European ancestry
• Estimated prevalence of 20 cases per 100,000 persons in the United States 1

Clinical Presentation and Symptoms

Classic Cranial Symptoms

• Headache - present in up to two-thirds of patients, often new-onset and severe in the temporal region 1, 2
• Scalp tenderness - painful sensitivity when touching the scalp or combing hair 1
• Jaw claudication - pain in the jaw muscles when chewing or talking, affects approximately 50% of patients 1
• Visual symptoms - occur in up to 20% of patients 1:
  • Amaurosis fugax (transient vision loss)
  • Diplopia (double vision)
  • Blurry vision
  • Permanent vision loss (occurs in 15-35% of untreated cases) 3
• Temporal artery abnormalities - including thickening, tenderness, and/or reduced pulsation 1

Systemic Manifestations

• Constitutional symptoms - present in about 50% of patients 1:
  • Weight loss
  • Night sweats
  • Malaise
  • Fever
• Polymyalgia rheumatica - muscle pain and stiffness, particularly in shoulders and hips 2
• Fatigue 1

Less Common Presentations

• Dry cough 4
• Tongue infarction 4
• Toothache 4
• Respiratory tract symptoms 4
• Stroke 1
• Cranial nerve palsy 1
• Scalp necrosis 1

Diagnostic Findings

Laboratory Findings

• Elevated inflammatory markers - present in >95% of GCA cases at diagnosis 1:
  • Erythrocyte sedimentation rate (ESR) >50 mm/hr in 89% of patients 4
  • Elevated C-reactive protein (CRP)
• Anemia - common finding 5

Diagnostic Imaging

• Ultrasound - "halo" sign (hypoechoic swelling around temporal arteries) with 77% sensitivity and 96% specificity 1
• MRI - can be used as an alternative when ultrasound is unavailable 1
• PET and CT - not recommended for assessment of cranial arteries but useful for evaluating large vessel involvement 1

Definitive Diagnosis

• Temporal artery biopsy - gold standard with specimen length ≥1 cm 1, 3
• Histopathological features include:
  • Arterial wall thickening
  • Narrowed lumen
  • Inflammatory cell infiltration
  • Multinucleated giant cells in the media (though not always present) 1

Complications and Prognosis

The most serious complication of temporal arteritis is permanent vision loss, which occurs in 15-35% of untreated patients 3. Once vision is lost, it is typically permanent, with high risk of losing vision in the second eye if treatment is delayed 3.

Other complications include:

• Large-vessel aneurysms and vascular stenoses 1
• Stroke 1
• Cranial nerve palsy 1
• Scalp necrosis 1

Treatment Approach

Immediate treatment is essential when GCA is suspected, as it can prevent permanent vision loss 2:

• Initial therapy: High-dose oral prednisone (40-60 mg/day) or IV pulse methylprednisolone (500-1000 mg/day for 3 days) for patients with visual symptoms 3
• Adjunctive therapy: Tocilizumab 162 mg subcutaneously weekly is recommended as first-line adjunctive agent to reduce glucocorticoid exposure 3
• Duration: Treatment typically required for 1-2 years with gradual tapering 1, 3

Key Clinical Pearls

1. Never delay treatment when GCA is clinically suspected, even before confirmatory tests 3
2. Temporal artery biopsy should be arranged promptly but should not delay initiation of treatment 3
3. Vision loss, once it occurs, is often permanent, emphasizing the importance of rapid diagnosis and treatment 3, 6
4. Approximately 60% of patients experience one or more relapses during glucocorticoid tapering 3
5. Temporal arteritis can mimic other conditions including angle-closure glaucoma, migraine, and trigeminal neuralgia 7

Early recognition of symptoms and prompt initiation of high-dose glucocorticoid therapy are crucial to prevent the devastating complication of permanent vision loss in patients with temporal arteritis.