Giant Cell Arteriris

Question 1

Define GCA

Answer 1

Granulomatous inflammation of large arteries, particularly branches of the external carotid artery, most commonly the temporal artery (Also called Temporal Arteritis)

Question 2

What are the causes/risk factors of GCA?

Answer 2

The exact cause remains unknown. It is probably triggered by an environmental cause in a genetically predisposed person. Genetic polymorphisms of HLA-DR4 and HLA-DRB1 are associated with susceptibility to GCA

Question 3

What are the symptoms of GCA?

Answer 3

• The disease onset is sub-acute, usually over a few weeks:
• Headache: Scalp and temporal tenderness; for example, pain on combing hair.
• Jaw and tongue claudication; e.g. unable to finish meals.
• Visual disturbances: Blurred vision, sudden blindness in one eye (amaurosis fugax). GCA results in granulomatous inflammation within the central retinal artery and posterior ciliary arteries of eye, resulting in partial or complete occlusion.
• Symptoms of polymyalgia rhuematica (PMR): Early morning pain and stiffness of the muscles of the shoulder and pelvic girdle (40–60% of cases are associated with PMR).
• Systemic features: FLAWS and depression.
• Neurological manifestations occur in about one third of patients and may include stroke, TIA, or neuropathy

Question 4

What are the signs of GCA?

Answer 4

• Swelling and erythema overlying the temporal artery.
• Thickened non-pulsatile temporal artery.
• Scalp and temporal tenderness.
• Reduced Visual acuity.
• Auscultation over the carotid or subclavian arteries may reveal bruits in patients with large-vessel involvement.

Question 5

What investigations are carried out for GCA?

Answer 5

• ESR - elevated; ≥50
• FBC - typically, patients have a normochromic, normocytic anaemia (ACD) with a normal WBC count and elevated platelet count; mild leukocytosis may occur.
• Temporal Artery Biopsy - within 48 h of starting corticosteroids. Note that a negative biopsy does not exclude the diagnosis, because skip lesions occur. When present, symptoms of jaw claudication and diplopia are powerful predictors of a positive temporal artery biopsy result.

Question 6

What is the management of GCA?

Answer 6

• Start on high dose oral prednisolone (40-60 mg/day) immediately to prevent visual loss. Prednisolone should not be delayed to wait for ESR or biopsy results. The majority of patients experience symptomatic relief within 48 hours of commencing steroid therapy.
• Taper down prednisolone dose according to ESR. Relapses on reducing the dose are common, and most patients require glucocorticoids for at least 1-2 years or longer.
• Low dose aspirin (plus PPIs) to reducd the risk of visual loss, TIAs or stroke.
• Osteoporosis prevention (adequate dietary calcium and vitamin D intake, bisphosphonates).

Visual Loss:
• IV pulse methylprednisolone (1 g for 3 days).
• Followed by oral prednisolone (60 mg/day, as above).

Monitoring:
• Annual CXR for up to 10 years to identify thoracic aortic aneurysms. If detected, monitor with CT every 6–12 months

Question 7

What are the complications of GCA?

Answer 7

• Carotid artery/aortic aneurysms
• Thrombosis may occur followed by recanalisation or embolism to the ophthalmic artery leading to visual disturbances, amaurosis fugax or sudden monocular blindness