What are the symptoms and treatment of Giant Cell Arteritis?

Symptoms of Giant Cell Arteritis (GCA)

Giant Cell Arteritis presents with headache, scalp tenderness, jaw claudication, and visual disturbances, with elevated inflammatory markers being highly characteristic of this potentially vision-threatening condition requiring urgent treatment. 1

Classic Cranial Symptoms

• Headache - typically new-onset, persistent, and localized to the temporal area - is a common presenting symptom but has limited diagnostic specificity 1, 2
• Scalp tenderness, particularly over the temporal arteries, occurs in many patients but also has limited diagnostic specificity 1, 2
• Jaw claudication (pain when chewing) is highly specific with a positive likelihood ratio of 4.90, making it one of the most diagnostically valuable symptoms 2
• Temporal artery abnormalities (tenderness, thickening, or reduced pulsation) have positive likelihood ratios of 3.14-4.70 1, 2

Visual Manifestations

• Visual disturbances range from transient blurred vision to permanent vision loss 1
• Anterior ischemic optic neuropathy is the most common cause of permanent visual loss 3
• Amaurosis fugax (temporary vision loss) may herald permanent visual loss 3
• Permanent visual loss occurs in 14-20% of patients and is typically devastating but preventable with early treatment 3

Constitutional and Systemic Symptoms

• Fever occurs in approximately 27% of patients (sensitivity 26.7%, specificity 78.0%) 1
• Polymyalgia rheumatica (PMR) symptoms (shoulder and hip girdle pain and stiffness) are present in about 33% of cases 1
• Weight loss and fatigue are common constitutional symptoms 4
• Myalgia is reported in approximately 40% of patients but has limited diagnostic value 1

Less Common Manifestations

• Limb claudication has high specificity (96.7%) but lower sensitivity (19.6%) 1
• Respiratory symptoms, particularly chronic cough, occur in <10% of cases 4
• Stroke, cranial nerve palsy, and scalp necrosis are rare but serious complications 4
• Uveitis is a rare presenting symptom that may delay diagnosis 5

Laboratory Findings

• Elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are found in >95% of cases 2
• ESR typically exceeds 40 mm/h, with values >100 mm/h having a positive likelihood ratio of 3.11 1, 2
• Anemia is common (sensitivity 87.4%) but has limited specificity (31.4%) 1
• Thrombocytosis (platelet count >400 × 10³/μL) is common and has diagnostic value 4, 2

Vascular Involvement

• Large vessel ("extracranial") involvement results in arterial stenosis and aneurysms 1
• Absent pulses and limb claudication may occur due to large vessel involvement 1
• Vascular imaging (ultrasound, MRI, PET, CT) can identify large vessel involvement beyond the temporal arteries 2

Treatment Approach

• High-dose glucocorticoid therapy (40–60 mg/day prednisone-equivalent) should be initiated immediately upon suspicion of GCA to prevent permanent vision loss 2, 6
• Tocilizumab has demonstrated efficacy in reducing glucocorticoid requirements and flare rates 2, 6
• Methotrexate may be used as a steroid-sparing agent to lower recurrence rates 7, 6

Diagnostic Pitfalls

• Normal ESR does not rule out GCA, as demonstrated by case reports of patients with normal ESR at presentation 8
• Atypical presentations (such as uveitis) may delay diagnosis and increase risk of complications 5
• Reliance solely on classic symptoms may miss cases with predominantly large vessel involvement 1