Polymyalgia rheumatica and temporal arteritis

Polymyalgia rheumatica and temporal arteritis are distinct but overlapping inflammatory conditions of unknown aetiology. They almost exclusively affect people over 50 years of age, women more than men (ratio 2–3:1), and particularly those of Nordic heritage.

Temporal arteritis is characterized by granulomatous inflammation that penetrates all layers of the wall of medium and (often) large muscular arteries, in particular the superficial temporal artery. Histological examination of tissues from patients with polymyalgia rheumatica shows nonspecific changes only. The term ‘giant cell arteritis’ is properly used only to describe patients with biopsy-proven arteritis.

Polymyalgia rheumatica

Clinical features—typical presentation is with symmetric limb girdle pain and/or stiffness, usually most pronounced in the morning or after rest, often associated with general constitutional symptoms, also with elevated levels of ESR and/or CRP. Peripheral arthritis occurs in one-quarter to one-third of patients.

Management—prednisolone at an initial dose of 15 mg/day is sufficient to suppress disease activity and provides significant relief in most patients. After remission is achieved, the dose is slowly reduced to a maintenance dose over the next few months and then continued for at least 12 months.

Temporal arteritis

Clinical features—the usual presentation is with headache (for which other causes are excluded), often followed by systemic symptoms—including malaise, weight loss, low-grade fever, loss of appetite, and night sweats—and in association with a significant acute phase response. Visual loss is a feared complication, most often caused by anterior ischaemic optic neuropathy. The temporal artery pulses are often reduced or absent, and there may be local tenderness.

Investigation—a temporal artery biopsy should be performed in all patients suspected of having temporal arteritis, but is not recommended in cases exhibiting no symptoms or signs of arteritis. Positive findings can be demonstrated even after 2 to 4 weeks of steroid therapy.

Management—prednisolone at an initial dose of 30 to 40 mg/day is recommended, increasing to 40 to 60 mg/day if there is no response. After remission is achieved, the dose is slowly reduced to a maintenance dose over the next few months, most patients needing treatment for several years. Visual disturbances can lead to permanent visual impairment and should be treated immediately with oral prednisolone at a dose of 60 to 80 mg/day.

The risk of developing arterial aneurysms is about 17 times greater than that of the general population, with aortic aneurysms causing death in 8% of patients.