Definition
- A primary vasculitis syndrome characterized by inflammation of medium-sized and large arteries
- Usually involves 1 or more cranial branches of the arteries originating from the aortic arch, particularly the temporal artery
- Systemic large-vessel vasculitis of multiple arteries may also occur.
- Classic presentation includes fever, anemia, high erythrocyte sedimentation rate (ESR), and headaches in a patient > 50 years of age.
- Other common features include jaw claudication and muscular symptoms identical to those of polymyalgia rheumatica.
- The most worrisome complication is permanent visual loss.
- For this reason, giant cell arteritis must be considered a medical emergency.
- Giant cell arteritis can manifest as 4 clinical phenotypes:
- Cranial features (including headache, visual loss, jaw claudication)
- Systemic inflammatory and constitutional symptoms
- Polymyalgia rheumatica
- Increasing evidence suggests that giant cell arteritis and polymyalgia rheumatica represent differing clinical spectrums of a single disease process.
- Large vessel vasculitis
- Also referred to as:
- Temporal arteritis
- Cranial arteritis
- Granulomatous arteritis
Epidemiology
- Incidence
- Varies widely among different studies and geographic regions
- In the U.S., annual rates (in persons ≥ 50 years) range from 6.9–32.8 per 100,000 persons.
- Prevalence
- 1–2 cases per 1000 in persons > 50 years
- Age
- Almost exclusively in persons > 50 years
- Incidence increases with age.
- Sex
- Female-to-male ratio, 2–6:1
- Race/ethnicity
- Highest incidence in persons of Scandinavian descent
- Rare in blacks
Risk Factors
- Age
- >50 years
- 20 times more common in people 70–80 years of age than 50–60 years of age
- Female sex
- Genetic factors
- HLA-DR4 allele expression
- HLA -DRB1 alleles, especially HLA-DRB1*04
Etiology
- Precise etiology is unknown.
- Likely to be multifactorial
- Genetic predisposition
- Environmental exposures
- Regulatory mechanisms associated with immune response to certain antigens
- Lesions show an inflammatory infiltrate with lymphocytes and macrophages dominating.
- HLA-DR4 predominance and local activation of T lymphocytes in the vasculitic lesions suggest an antigen-driven immune-mediated disease.
Associated Conditions
- Polymyalgia rheumatica
- Characterized by stiffness, aching, and pain in the muscles of the neck, shoulders, lower back, hips, and thighs
- Often occurs in isolation, but may be seen in 40–50% of patients with giant cell arteritis
- ~10–20% of patients who initially present with features of isolated polymyalgia rheumatica later go on to develop giant cell arteritis.
Giant Cell Arteritis is a sample topic found in
Harrison's Practice.
To find other Harrison's Practice topics
please login or purchase a subscription.
![[Display All Sections]](images/m/display_all_btn.png)
CrossLinks