Polymyalgia Rheumatica (PMR) and Giant Cell Arteritis (GCA)

Question 1

What is Polymyalgia Rheumatica?

Answer 1

Rheumatological syndrome that presents as bi-lateral aching, tenderness and morning stiffness involving the neck, shoulder girdle and pelvic girdle

• Autoimmune condition

Question 2

What is Giant cell Arteritis?

Answer 2

Common form of vasculitis of large and medium sized arteries. GCA primarily affects branches of the external carotid artery

Question 3

What are the risk factors of Polymyalgia Rheumatica?

Answer 3

• Age (> 50 years)
• GCA
• Gender (female)

Question 4

What are the clinical features of Polymyalgia Rheumatica?

Answer 4

• Bi-lateral aching, tenderness and morning stiffness in shoulders, hips and proximal limb muscles
• Fever
• Weight loss and anorexia
• Depression
• Headache, scalp tenderness

Question 5

What is the differential diagnosis of Polymyalgia Rheumatica?

Answer 5

• GCA
• Recent onset Rheumatoid Arthritis
• Hypothyroidism
• Fibromyalgia
• Osteoarthritis
• Polymyositis

Question 6

What is the pathophysiology of Polymyalgia Rheumatica?

Answer 6

• Mutation of the HLA-DR4 gene, immune system no longer recognises proteins and muscles as self
• Proteins become autonantigens
• Autoantigens engulfed by dendritic cells and presented on surface
• T cells and macrophages attracted
• Immune cells enter circulation and travel to joints releasing cytokines

=> Cytokines involved:

• Interleukin 1
• Interleukin 6
• Tumour Necrosis Factor alpha

These cytokines promote inflammation of surrounding tissues not the muscles. THEREFORE CREATININE KINASE NOT RAISED AS MUSCLES NOT DAMAGED

Question 7

Why does fever occur in Polymyalgia Rheumatica?

Answer 7

Cytokines travel to end organs like brain and act as pyrogens, causing fever

Question 8

What are the investigations in suspected Polymyalgia Rheumatica?

Answer 8

=> Inflammatory markers

• CRP elevated
• ESR elevated
• CK not elevated

=> Temperature - High

=> Ultrasound

Question 9

What is the management of Polymyalgia Rheumatica?

Answer 9

• Steroids given for immunosupression
• Predinisolone PO
• Decrease dose slowly over a month
• Keep giving steroids for 2 years
• Exercise to improve symptoms

Question 10

What is Giant Cell Arteritis?

Answer 10

Inflammation of arteries. Characterised as:

• Small cell
• Medium cell
• Large cell (this type is known as Giant cell Arteritis)

Question 11

What are the risk factors of Giant Cell Arteritis?

Answer 11

• Age > 50 years
• Gender - female
• Smoking
• Atherosclerosis

Question 12

What are the clinical features of Giant Cell Arteritis?

Answer 12

• Scalp tenderness
• Headaches
• Vision loss (starts with unilateral vision loss and can progress to bilateral)
• Tongue and jaw claudication

=> Scalp tenderness and headaches due to effects on temporal artery
=> Vision loss due to effects on the ophthalmic artery

Question 13

What is the differential diagnosis of Giant Cell Arteritis?

Answer 13

• Polymyalgia Rheumatica
• Rheumatoid Arthritis
• SLE
• Takayasu’s Arteritis

Question 14

What are the investigations in suspected Giant Cell Arteritis?

Answer 14

=> Bloods - CRP, ESR, ALP, platelets

All elevated

=> Temporal artery biopsy
- Must do within 14 days of prescribing steroids

=> Temporal artery ultrasound
- When biopsy is not readily available

Question 15

What is the management of Giant Cell Arteritis?

Answer 15

• PO Predinisolone or IV Methylpredinisolone in cases of vision loss