Polymyalgia rheumatica and giant cell arteritis. Avoiding management traps.

BACKGROUND: Polymyalgia rheumatica (PMR) needs to be considered in the patient over 55 years of age who presents with stiffness and pain. It appears to exist in a continuum with giant cell arteritis (GCA), and the differential diagnosis is large. It may affect one in 200 patients in this age group. Corticosteroid toxicity is a major problem, either because of inappropriate dosage or prolonged disease.

OBJECTIVE: To provide an up to date understanding of the concepts of this group of disorders in order to allow rapid recognition, better management, and to minimise toxicity of the necessary treatment. The most important of these are the appropriate dose of corticosteroid and instituting preventive therapy for potential complications such as osteoporosis.

DISCUSSION: As there is no specific test for PMR, the diagnosis is still made on clinical grounds from the presentation, symptoms and signs, and the presence of serological markers of inflammation. Because these are all nonspecific, alternative diagnoses must be actively excluded. Certain newer investigations, such as high resolution ultrasound of the temporal arteries may be very helpful in directing temporal artery (TA) biopsies. When the response to treatment does not follow the usual course (and this may be prolonged: 18 months to five years or more), then re-evaluation is imperative.