Polymyalgia rheumatica

Question 1

What is polymyalgia rheumatica?

Answer 1

PMR, inflammatory syndrome that manifests as pain and morning stiffness involving neck, shoulder or pelvic girdle.

Question 2

What is the aetiology of PMR? (x3)

Answer 2

Unknown but infectious agents such as adenovirus, respiratory syncytial virus, parvovirus B18, Mycoplasma pneumoae and Chlamydia pneumoniae have been implicated. There is also HLA-DRB association, and adrenal hypofunction is linked to the condition.

Question 3

What is the pathophysiology of PMR?

Answer 3

PMR can occur as an isolated condition or associated with GCA. Given the association with GCA, it is thought that mechanisms are similar. Believed that PMR has T cell autoimmune pathophysiology, with IL-6 production, but no IFN-gamma expression unlike GCA. IFN-gamma production is believed to contribute to vasculitis, which is NOT a symptom of PMR, but is of GCA.

Question 4

What is the epidemiology of PMR: Age? Gender? Giant cell arteritis?

Answer 4

Over 50 years old. More common in women. 20% of PMR patients have GCA, 50% of GCA patients have PMR.

Question 5

What are the signs and symptoms of PMR? (x6) Onset?

Answer 5

• Acute onset, and relapsing
• Shoulder/hip girdle morning stiffness and morning pain. Peripheral myalgia/arthralgia less common
• Oligoarthritis
• Muscle tenderness
• Difficult rising from seated to prone
• Shoulder/hip bursitis
• Constitutional symptoms: fever, malaise, weight loss

Question 6

What are the investigations for PMR? (x3)

Answer 6

• Clinical diagnosis supported by bloods
• BLOODS: raised CRP and ESR (ESR is also prognostic of relapse)
• USS: to assess bursitis and joint effusions (arthritis)

Question 7

How is PMR managed? (x4)

Answer 7

• FIRST LINE: CORTICOSTEROID: low-dose prednisolone with rapid response within 72 hours
• OSTEOPOROSIS PREVENTION: calcium and vitamin D supplement with bisphosphonate as corticosteroid therapy (which often is given for at least a year) predisposes osteoporosis
• SECOND LINE: METHOTREXATE: can be used as alternative therapy to corticosteroid PLUS FOLIC ACID to decrease the risk of adverse effects of methotrexate, particularly oral ulcers and bone marrow suppression
• THIRD LINE: TOCILIZUMAB

Question 8

What are the complications of PMR? (x3)

Answer 8

Relapse, GCA, vascular events