Polymyalgia rheumatica (PMR) is an inflammatory condition that causes pain and stiffness in the shoulder girdle, the hip girdle, neck and lower back.
Symptoms can start abruptly overnight or come on gradually over weeks. The achiness and stiffness is usually worse in the mornings and slowly improves over the course of the day. Often patients have difficulty turning over in bed or getting dressed in the morning.
The cause of PMR is not known, but seems to start more commonly in spring and summer suggesting an environmental trigger.
It tends to only occur in those over the age of 50, and the risk increases with increasing age
People of northern European descent are more likely to get the disorder suggesting a genetic predisposition.
Diagnosis is based on the symptoms, exclusion of other conditions that can mimic the disorder (including cancers), and the finding of raised inflammatory markers in the blood (CRP or ESR). In a small percentage of people the inflammatory markers may be normal.
Imaging of the shoulder or hip girdle with ultrasound, MRI or FDG-PET scan may show bursitis (inflammation of the fluid sac), tenosynovitis (inflamed tendons) and synovitis (inflamed joints) in these regions.
Treatment is with a steroid medication called prednisone. Occasionally intramuscular steroid on a regular basis may be used as an alternative. Steroids are normally required for a minimum of 2 years, often up to 5 years or more. Medication which may reduce the dose of steroids needed to treat PMR can be used such as methotrexate and leflunomide.
Prednisone unfortunately has lots of long-term side effects such as weight gain, osteoporosis, cataracts, increasing the risk of diabetes, etc. so part of treatment is also to try and mitigate these side effects.
About a 1/4 of patients with PMR can get an associated condition called giant cell arteritis (GCA). The risk is highest in those that are inadequately treated for PMR. In GCA there is inflammation of large arteries, most commonly those going to the brain and eyes. The symptoms are new persistent headaches, jaw muscle aching when chewing, scalp tenderness, fevers or night sweats. The dreaded symptom is visual loss which can be permanent.
If you have PMR and get any of these other symptoms suggestive of GCA – this is a medical emergency and you should contact your doctor straight away. Diagnosis is based on symptoms, ultrasound of the relevant vessels showing inflammation (halo sign) and/or biopsy of the temporal arteries. Urgent treatment is needed to prevent blindness and stroke.