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Emergency And Acute Medicine - Giant Cell Arteritis (Temporal Arteritis)
Basics Description
Giant cell arteritis is a chronic vasculitis of large- and medium-sized arteries occurring almost exclusively in individuals older than 50 years. It is commonly referred to as temporal arteritis. The median age at onset is approximately 72 years. The disease most often involves arteries arising from the aortic arch. Although frequently clinically silent, thoracic aortic involvement is common and may lead to aneurysm or dissection. Thoracic aortic aneurysm occurs at a rate nearly 17 times higher than in those without giant cell arteritis, while abdominal aortic aneurysm is about twice as common.
Pathologic specimens demonstrate patchy mononuclear granulomatous inflammation with marked intimal thickening and luminal occlusion. Occlusive arteritis may involve the ophthalmic artery, resulting in anterior ischemic optic neuropathy and acute visual loss, which constitutes an ophthalmic emergency. Inflammation of arteries supplying the muscles of mastication causes jaw claudication and tongue discomfort.
Age is the greatest risk factor; the disease is rare in patients younger than 50 years and more than 90% of cases occur in those older than 60 years. Prevalence in individuals over 50 is approximately 1:500, with higher rates in northern latitudes. It is two to four times more common in women, rare in African American patients, and more common in White populations. There is a strong association with polymyalgia rheumatica, present in approximately 50% of patients. A genetic predisposition is linked to HLA-DR4.
Etiology
The exact cause is unknown. Genetic, environmental, and autoimmune factors are believed to contribute.
Diagnosis
The diagnosis is supported by the presence of three or more of the following in a patient with vasculitis: age greater than 50 years, erythrocyte sedimentation rate greater than 50 mm/hr, new-onset localized headache, temporal artery tenderness or decreased pulsation, new visual symptoms, and biopsy demonstrating necrotizing arteritis.
Signs And Symptoms
Symptoms may be acute, subacute, or chronic. Headache is the most common symptom, occurring in approximately 70% of patients, and is often unilateral, localized to the temple, and described as boring or lancinating. Jaw or tongue claudication with chewing occurs in about 50%. Constitutional symptoms include fatigue, malaise, anorexia, weight loss, weakness, arthralgias, and low-grade fever.
Visual manifestations usually involve one eye and may develop weeks to months after other symptoms. These include amaurosis fugax, blindness, diplopia, ptosis, extraocular muscle weakness, scotomata, and blurred vision. Visual impairment typically does not improve, even with treatment.
Other findings include scalp tenderness, especially over the temporal artery; early increased pulsations followed by decreased pulsations later in disease; erythema, warmth, swelling, or nodules over scalp arteries; bruits or diminished pulses over large arteries; sore throat, cough, and dysphagia. Neurologic manifestations such as neuropathies, transient ischemic attacks, and strokes may occur in up to one-third of patients. Occult manifestations include glossitis, lingual infarction, tongue infarction, and Raynaud phenomenon. Up to 30% of patients may lack classic symptoms.
Polymyalgia rheumatica is frequently associated, characterized by morning stiffness and aching pain of proximal muscles that improves with activity and may be accompanied by synovitis, particularly in the knees.
Essential Workup
A focused physical examination should emphasize the temporal arteries and scalp, a complete neurologic examination, and a detailed ophthalmic examination including visual acuity and visual fields. Fundoscopy may be normal early but can show optic nerve edema, pallor, hemorrhages, cotton-wool spots, and exudates later. Pulse asymmetry or bruits over large arteries should be documented.
Diagnosis Tests And Interpretation
Laboratory findings typically include a markedly elevated ESR, often greater than 100 mm/hr, and elevated C-reactive protein. Mild normochromic anemia and mild thrombocytosis are common. White blood cell count is usually normal or mildly elevated. Liver enzymes and prothrombin time may be elevated, while renal function and urinalysis are usually normal. Interleukin-6 levels are elevated during disease flares.
Imaging may include Doppler ultrasound showing decreased flow and a characteristic halo sign in temporal arteries. MRI can assess large-vessel involvement. Angiography may reveal smooth, tapered stenoses or occlusions.
Temporal artery biopsy is the diagnostic gold standard and should include multiple sections. It should be performed as soon as feasible after starting steroids. If the initial biopsy is negative and suspicion remains high, contralateral biopsy is recommended.
Differential Diagnosis
Other vasculitides including polyarteritis nodosa, hypersensitivity vasculitis, systemic lupus erythematosus, Takayasu arteritis, and granulomatosis with polyangiitis; retinal, ophthalmic, or temporal artery thrombosis; Lyme disease; and nonarteritic anterior ischemic optic neuropathy.
Treatment Prehospital
Symptoms may be mistaken for stroke. Provide monitoring and supplemental oxygen. Hypotension may occur from rare complications such as aortic dissection, abdominal aortic aneurysm, or myocardial infarction.
Initial Stabilization Therapy
Although uncommon, patients may present with vascular catastrophes requiring aggressive early management consistent with standard emergency protocols.
Ed Treatment Procedures
High-dose corticosteroids are the cornerstone of therapy. When clinical suspicion is strong, steroid treatment should not be delayed for biopsy, as vascular pathologic changes persist for weeks. Early aggressive treatment significantly reduces the risk of blindness. Systemic and local symptoms typically improve within days to weeks, but treatment may be required for several years, with an average disease course of three to four years. Analgesia with NSAIDs, salicylates, or narcotics may be provided as needed.
Medication
Prednisone 60–100 mg orally daily for at least two weeks before tapering. For acute visual symptoms, intravenous methylprednisolone 1,000 mg daily for one to three days may be used. Low-dose aspirin is recommended to reduce thrombotic risk. NSAIDs or narcotics may be used for pain control.
Follow-Up Disposition
Admission is indicated for patients with acute visual loss, impending vascular complications, or acute focal neurologic deficits. Less symptomatic patients without evidence of end-organ damage may be discharged with close follow-up arranged within one to two days.
Issues For Referral
Rheumatology for disease management, ophthalmology for visual symptoms, and neurology for focal neurologic findings.
Follow-Up Recommendations
Ongoing care with rheumatology for steroid management and evaluation for associated connective tissue disease. Ophthalmology and neurology follow-up are required for visual or neurologic involvement.
Key Clinical Insights And Common Errors
Permanent visual loss is the most feared complication. Steroid therapy must not be delayed when clinical suspicion is high or visual symptoms are present. Jaw claudication and amaurosis fugax are often underreported and should be specifically queried. Between 25% and 50% of patients with untreated unilateral visual loss will progress to bilateral blindness.
Basics Description
Giant cell arteritis is a chronic vasculitis of large- and medium-sized arteries occurring almost exclusively in individuals older than 50 years. It is commonly referred to as temporal arteritis. The median age at onset is approximately 72 years. The disease most often involves arteries arising from the aortic arch. Although frequently clinically silent, thoracic aortic involvement is common and may lead to aneurysm or dissection. Thoracic aortic aneurysm occurs at a rate nearly 17 times higher than in those without giant cell arteritis, while abdominal aortic aneurysm is about twice as common.
Pathologic specimens demonstrate patchy mononuclear granulomatous inflammation with marked intimal thickening and luminal occlusion. Occlusive arteritis may involve the ophthalmic artery, resulting in anterior ischemic optic neuropathy and acute visual loss, which constitutes an ophthalmic emergency. Inflammation of arteries supplying the muscles of mastication causes jaw claudication and tongue discomfort.
Age is the greatest risk factor; the disease is rare in patients younger than 50 years and more than 90% of cases occur in those older than 60 years. Prevalence in individuals over 50 is approximately 1:500, with higher rates in northern latitudes. It is two to four times more common in women, rare in African American patients, and more common in White populations. There is a strong association with polymyalgia rheumatica, present in approximately 50% of patients. A genetic predisposition is linked to HLA-DR4.
Etiology
The exact cause is unknown. Genetic, environmental, and autoimmune factors are believed to contribute.
Diagnosis
The diagnosis is supported by the presence of three or more of the following in a patient with vasculitis: age greater than 50 years, erythrocyte sedimentation rate greater than 50 mm/hr, new-onset localized headache, temporal artery tenderness or decreased pulsation, new visual symptoms, and biopsy demonstrating necrotizing arteritis.
Signs And Symptoms
Symptoms may be acute, subacute, or chronic. Headache is the most common symptom, occurring in approximately 70% of patients, and is often unilateral, localized to the temple, and described as boring or lancinating. Jaw or tongue claudication with chewing occurs in about 50%. Constitutional symptoms include fatigue, malaise, anorexia, weight loss, weakness, arthralgias, and low-grade fever.
Visual manifestations usually involve one eye and may develop weeks to months after other symptoms. These include amaurosis fugax, blindness, diplopia, ptosis, extraocular muscle weakness, scotomata, and blurred vision. Visual impairment typically does not improve, even with treatment.
Other findings include scalp tenderness, especially over the temporal artery; early increased pulsations followed by decreased pulsations later in disease; erythema, warmth, swelling, or nodules over scalp arteries; bruits or diminished pulses over large arteries; sore throat, cough, and dysphagia. Neurologic manifestations such as neuropathies, transient ischemic attacks, and strokes may occur in up to one-third of patients. Occult manifestations include glossitis, lingual infarction, tongue infarction, and Raynaud phenomenon. Up to 30% of patients may lack classic symptoms.
Polymyalgia rheumatica is frequently associated, characterized by morning stiffness and aching pain of proximal muscles that improves with activity and may be accompanied by synovitis, particularly in the knees.
Essential Workup
A focused physical examination should emphasize the temporal arteries and scalp, a complete neurologic examination, and a detailed ophthalmic examination including visual acuity and visual fields. Fundoscopy may be normal early but can show optic nerve edema, pallor, hemorrhages, cotton-wool spots, and exudates later. Pulse asymmetry or bruits over large arteries should be documented.
Diagnosis Tests And Interpretation
Laboratory findings typically include a markedly elevated ESR, often greater than 100 mm/hr, and elevated C-reactive protein. Mild normochromic anemia and mild thrombocytosis are common. White blood cell count is usually normal or mildly elevated. Liver enzymes and prothrombin time may be elevated, while renal function and urinalysis are usually normal. Interleukin-6 levels are elevated during disease flares.
Imaging may include Doppler ultrasound showing decreased flow and a characteristic halo sign in temporal arteries. MRI can assess large-vessel involvement. Angiography may reveal smooth, tapered stenoses or occlusions.
Temporal artery biopsy is the diagnostic gold standard and should include multiple sections. It should be performed as soon as feasible after starting steroids. If the initial biopsy is negative and suspicion remains high, contralateral biopsy is recommended.
Differential Diagnosis
Other vasculitides including polyarteritis nodosa, hypersensitivity vasculitis, systemic lupus erythematosus, Takayasu arteritis, and granulomatosis with polyangiitis; retinal, ophthalmic, or temporal artery thrombosis; Lyme disease; and nonarteritic anterior ischemic optic neuropathy.
Treatment Prehospital
Symptoms may be mistaken for stroke. Provide monitoring and supplemental oxygen. Hypotension may occur from rare complications such as aortic dissection, abdominal aortic aneurysm, or myocardial infarction.
Initial Stabilization Therapy
Although uncommon, patients may present with vascular catastrophes requiring aggressive early management consistent with standard emergency protocols.
Ed Treatment Procedures
High-dose corticosteroids are the cornerstone of therapy. When clinical suspicion is strong, steroid treatment should not be delayed for biopsy, as vascular pathologic changes persist for weeks. Early aggressive treatment significantly reduces the risk of blindness. Systemic and local symptoms typically improve within days to weeks, but treatment may be required for several years, with an average disease course of three to four years. Analgesia with NSAIDs, salicylates, or narcotics may be provided as needed.
Medication
Prednisone 60–100 mg orally daily for at least two weeks before tapering. For acute visual symptoms, intravenous methylprednisolone 1,000 mg daily for one to three days may be used. Low-dose aspirin is recommended to reduce thrombotic risk. NSAIDs or narcotics may be used for pain control.
Follow-Up Disposition
Admission is indicated for patients with acute visual loss, impending vascular complications, or acute focal neurologic deficits. Less symptomatic patients without evidence of end-organ damage may be discharged with close follow-up arranged within one to two days.
Issues For Referral
Rheumatology for disease management, ophthalmology for visual symptoms, and neurology for focal neurologic findings.
Follow-Up Recommendations
Ongoing care with rheumatology for steroid management and evaluation for associated connective tissue disease. Ophthalmology and neurology follow-up are required for visual or neurologic involvement.
Key Clinical Insights And Common Errors
Permanent visual loss is the most feared complication. Steroid therapy must not be delayed when clinical suspicion is high or visual symptoms are present. Jaw claudication and amaurosis fugax are often underreported and should be specifically queried. Between 25% and 50% of patients with untreated unilateral visual loss will progress to bilateral blindness.
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