What are the complications of giant cell arteritis?

Complications of Giant Cell Arteritis

Giant cell arteritis (GCA) can lead to serious complications including permanent vision loss in 14-18% of patients, stroke, cranial nerve palsy, scalp necrosis, and large-vessel aneurysms and stenoses that can significantly impact morbidity and mortality. 1

Ocular Complications

• Vision loss: Occurs in approximately 18% of patients at diagnosis and is usually irreversible 1
• Amaurosis fugax (temporary vision loss): Occurs in about 20% of patients 1
• Delayed treatment can result in permanent vision loss in 15-35% of untreated GCA patients 1

Neurological Complications

• Stroke: Due to inflammation and occlusion of cranial arteries 2, 1
• Cranial nerve palsies: Resulting from ischemia of cranial nerves 2, 1
• Hemiparesis: Due to cerebrovascular involvement 1

Vascular Complications

• Large-vessel aneurysms: Particularly affecting the aorta and its major branches 2, 1
• Vascular stenoses: Narrowing of affected vessels leading to ischemia 2
• Aortic dissection: A potentially life-threatening complication 3
• Scalp necrosis: Due to severe ischemia of scalp tissues 2, 1

Systemic Complications

• Polymyalgic symptoms: Including muscle pain and stiffness 2
• Constitutional symptoms: Fever, malaise, fatigue, and weight loss 1
• Respiratory manifestations: Harsh, nonproductive cough 1
• Throat symptoms: Sore throat and hoarseness 1

Treatment-Related Complications

Glucocorticoid therapy, the mainstay of GCA treatment, can lead to significant adverse effects:

• Diabetes mellitus: Requiring regular blood glucose monitoring 1
• Osteoporosis: Necessitating calcium, vitamin D supplementation, and bisphosphonates 1
• Hypertension: Requiring blood pressure monitoring 1
• Increased infection risk: Due to immunosuppression 1
• Cataracts: With long-term steroid use 1

Long-Term Prognosis

• Disease relapses occur in 34-62% of patients 2, 1
• Only 15-20% of patients achieve sustained remission with glucocorticoids alone 2
• With appropriate treatment, overall mortality rates in GCA appear similar to the general population 4

Clinical Pitfalls and Caveats

• Delayed diagnosis: Can lead to irreversible complications, particularly vision loss
• Inadequate initial treatment: Treatment should not be delayed while awaiting biopsy results 1
• Insufficient monitoring: Regular clinical and laboratory monitoring is essential to detect relapses
• Neglecting steroid-related complications: Preventive measures must be implemented from the start of treatment

Management Approach to Prevent Complications

1. Immediate treatment initiation upon clinical suspicion

   • Uncomplicated GCA: 40-60 mg/day oral prednisone
   • GCA with visual symptoms: 500-1000 mg/day IV methylprednisolone 1

2. Consider steroid-sparing agents:

   • Tocilizumab (162 mg subcutaneously weekly) to reduce glucocorticoid requirements and prevent relapses 1
   • Methotrexate or leflunomide as alternative options 1

3. Regular monitoring:

   • Clinical symptoms
   • Inflammatory markers (ESR, CRP)
   • Vascular imaging when appropriate 1

4. Prevention of glucocorticoid-induced side effects:

   • Bone protection therapy (calcium, vitamin D, bisphosphonates)
   • Blood pressure and glucose monitoring
   • Regular screening for cataracts and other complications 1

The recognition of these complications underscores the importance of prompt diagnosis and aggressive treatment of GCA to prevent irreversible damage and improve long-term outcomes.