Giant Cell Arteritis Flashcards
Giant Cell Arteritis
Systemic vasculitis typically affects the cranial artery including the opthalmic artery.
- Can also affect other large blood vessels including aorta and its major branches.
Clinical Features
- Age >= 50 in almost all cases
- F > M
- Incidence increases in age with peak in 70-79yo
- Symptoms - Severe temporal headache, jaw claudication, polymyalgia rheumatica in 50% of cases, visual symptoms (diplopia, visual loss), scalp tenderness, malaise.
- Examination - Temporal artery is tender, enlarged, difficult to compress, pulseless or nodular,.
- Reduced visual acuity
Ix - ESR and CRP raised. ESR can be normal initially.
- Gold standard diagnostic test - Temporal artery biopsy (Note: Changes persist for at least 1 week after treatment is started. Can commence treatment and chase biopsy afterwards.
Management
- Prednisolone 1mg/kg max 60mg PO OD . Titrate according to ESR response. uncommon to cease before 18 months. Check inflammatory markers every month for first 3 months then every 2-3 months thereafter or when clinically indicated.
- Evolving visual loss? Treat as inpatient with IV Methylprednisolone sodium succinate 0.5-1g IVIF over 1 hour OD for 3 days then switch to orals.
- Aspirin 100mg PO OD (Prevent ischaemic events)
- Methotrexate 10mg PO Weekly + Folic acid 5mg PO Weekly. Can be used as corticosteroid-sparing therapy if early CS SE experienced.
- Refer to rheumatologist for ongoing management
- Educate to present to emergency department if visual changes occur.
Diagnosis of GCA
American College of Rheumatology criteria.
Presence of at least three of following criteria
- Age >= 50yo
- New onset localised headache
- Temporal artery tenderness or reduced pulse
- ESR >= 50
- Abnormal Temporal artery biopsy
3+ of above findings provides sensitivity of 93.5% and specificity of 91.2%
