Supplement Article |
OP5. GCA AND PMR: A GENERAL PRACTITIONER'S PERSPECTIVE
General practitioner, Glasgow, UK
PMR can be a challenging condition within primary care. Diagnosis can be difficult as it largely depends on having a high index of suspicion supported by history, examination and raised levels of inflammatory markers which of course are not specifically diagnostic for PMR. The incidence of PMR has variously been reported as between 13 and 68 per 100,000 of the population aged over 50 with a peak incidence around age 70. As most general medical practitioners in the UK look after a patient population of around 2000 patients it follows that a new case of PMR does not occur frequently in most GPs clinical practice. General practitioners whose patient population is skewed towards a younger age group may only rarely see a case of PMR and may develop little experience of dealing with the condition.
When PMR presents with classical clinical features of a sudden onset of stiffness and pain in shoulder and pelvic girdles, with tenderness of shoulder muscles and some systemic features of debility, weight loss, tiredness and low-grade fever together with a raised ESR the diagnosis can be fairly straightforward. If the symptoms are not rapidly relieved within a few days with steroid therapy (15 mg/day prednisolone) the diagnosis should be re-considered and various laboratory tests should be undertaken to exclude conditions such as multiple myeloma, other malignancy, connective tissue disease, inflammatory arthritis, myopathy, and myositis.
One of the most difficult differential diagnoses is that of rheumatoid arthritis. A polymyalgic presentation of RA may occur especially in elderly patients and in the very early stages before there are overt joint signs such as synovitis, may very closely resemble PMR. Generally these patients do not have a rapid response to steroid therapy.
It is important to remember the overlap between PMR and GCA. These two conditions may in fact represent opposite ends of the spectrum of the same disease with PMR at the milder end. All patients suspected of having PMR should be asked about symptoms of headache, jaw claudication and scalp tenderness and if present the patient should be referred immediately for a temporal artery biopsy and treatment with higher dose steroids. If immediate referral is not possible patients should be treated with high dose steroids in primary care to avoid possible blindness.
PMR is a challenging condition in primary care but can be very satisfying to treat as patients often have a very dramatic response to therapy and are most grateful for the relief of their symptoms.