Giant Cell Arteritis

Question 1

What is giant cell arteritis? GCA

Answer 1

A chronic vasculitis of large and medium sized vessels.

It is an inflammatory granulomatous arteritis of large cerebral arteries, usually originating from the arch of the aorta.

Question 2

Epidemiology of GCA.

Answer 2

Over 50 years of age

Median age of onset is 72 yo.

Women are more commonly affected.

Question 3

Risk factors of GCA.

Answer 3

Age

90% of cases are > 60 yo

Increased prevalence in northern latitude.

More common in caucasians

More common in women

Strong association with polymyalgia rheumatica (PMR).

Genetics HLA-DR4

Question 4

Clinical features of GCA.

Answer 4

Headache

Temporal artery and scalp tenderness e.g. when combing hair.

Tongue/jaw claudication

Amaurosis fugax

Sudden unilateral blindness

General symptoms:

Malaise, dyspnoea, weight loss, morning stiffness and unequal or weak pulses.

Question 5

Explain the headache in GCA.

Answer 5

Often localised, unilateral, boring or lancinating in quality over the temple.

Question 6

Give examples of visual symptoms of GCA.

Answer 6

Amaurosis fugax

Blindness

Diplopia

Blurring

Question 7

Investigations of GCA.

Answer 7

• ESR and CRP both elevated
• Platelets elevated
• ALP elevated
• Hb decreased
• Temporal biopsy (definitive diagnosis)
• Ultrasound scanning is becoming increasingly used.

Question 8

When should temporal biopsy be done?

Answer 8

Should be done before or within 14 days of starting steroids.

Question 9

How is the diagnosis of GCA made?

Answer 9

• Two or more of the following in a patient > 50yo:
• Raised ESR, CRP or PV (usually 50 mm/hour or more)
• New onset of localised headache
• Tenderness or decreased pulsation of temporal artery
• New visual symptoms
• Biopsy revealing necrotising arteritis

Question 10

Histological features of GCA.

Answer 10

a Multinucleated giant cells are found on the temporal artery biopsy. This is what gives rise to the giant cell arteritis name.

Cellular infiltrates of CD4+ T lymphocytes, macrophages and giant cells in the vessel wall.

Granulomatous inflammation of the intima and media

Breaking up of the internal elastic lamina

Giant cells, lymphocytes and plasma cells in the internal elastic lamina.

Question 11

Treatment of GCA.

Answer 11

Start prednisolone 60-100mg PO OD for at least 2 weeks before considering tapering down slowly.

There should be a rapid in significant response, review within 48h.

If there is acute onset of visual loss go IV methylprednisolone 1g for 1-3 days.

Low dose aspirin should also be given to reduce thrombotic risk + PPi

Question 12

What referrals should be done in GCA?

Answer 12

Vascular surgeons for a temporal artery biopsy in all patients with suspected GCA

Rheumatology for specialist diagnosis and management

Ophthalmology review as an emergency same day appointment if they develop visual symptoms

Question 13

Ongoing management of GCA.

Answer 13

They need to slowly wean off the steroids, it’s a high dose they are given (60-100mg) and this can take a long time to reduce to nothing.

DON’T – Don’t stop taking steroids abruptly. There is a risk of adrenal crisis.

S – Sick Day Rules.

T – Treatment Card.

O – Osteoporosis prevention with bisphosphonates and supplemental calcium and vitamin D.

P – Proton pump inhibitor for gastric protection.

Question 14

Early complications of GCA

Answer 14

Vision loss

Stroke

Question 15

Late complications of GCA

Answer 15

Relapse

Steroid related ADRs

Stroke

Aortitis -> aortic aneurysm and dissection