Polymyalgia Rheumatica (PMR)
Polymyalgia Rheumatica (PMR) is a condition associated with adults of older age, and essentially is thought not to occur in anyone <55 years old. The features of PMR are:
• achy pain of neck and shoulder muscles on waking in the morning which ease with movement (sometimes also muscles of the 'pelvic girdle' area);
• the absence of any other identifiable inflammatory joint or other musculoskeletal condition;
• evidence of inflammation in the blood (high ESR and CRP values);
• the symptoms respond promptly to steroid tablets (15-20mg prednisolone daily).
Whether PMR is a single autoinflammatory condition or a symptom complex common to a number of different underlying disease processes, is unknown. For example, an acute episode of CPP disease of neck, spine and shoulders can give all of the features (bulleted) above; as can an episode of enthesitis-predominant psoriatic arthritis or spondyloarthritis. In a pure sense then, if PMR is always one of these three conditions then PMR does not exist!
General practitioners usually do not have the knowledge, skills and expertise to reliably exclude CPP disease, axial spondyloarthritis and enthesitis-predominant psoriatic arthritis. Ideally to unravel 'PMR' a person needs referral to a Rheumatologist who has the skills to diagnose these conditions (appropriate knowledge about the diseases, appropriate examination skills and access to all the relevant imaging investigations), though many general practitioners/family doctors take a pragmatic view of the condition and treat with steroids without too much investigation.
Giant cell arteritis (GCA) is a condition where the larger arteries become inflamed - this is termed a 'vasculitis' condition. It is very important to identify GCA and treat it promptly because the inflamed arteries can narrow and get blocked preventing blood getting to vital places in the body - like the eye and brain. The worst possible situation can be when GCA is not identified or treated and the affected person goes blind or has a stroke. GCA is associated with 'PMR'. A minority of people with 'PMR' get GCA but a greater proportion who get GCA have 'PMR' symptoms also.
The diagnosis of GCA is made by rheumatologists and ophthalmologists together. Tests include: detailed eye examination, lab tests, an ultrasound of the temporal artery (side of scalp), biopsy of the temporal artery and sometimes a positron emission tomography scan (PET). All UK NHS hospitals have a service for GCA (telephone advice / A&E visit / prompt triage for tests- assessments / treatment). The treatment is (quite high) dose steroids (prednisolone 40-60mg daily) - necessarily so because dose the consequences can be very serious if GCA is under-treated.
Links
Information for patients from American College of Rheumatology:
www.rheumatology.org/I-Am-A/Patient-Caregiver/Diseases-Conditions/Polymyalgia-Rheumatica
Information on GCA:
https://www.versusarthritis.org/about-arthritis/conditions/giant-cell-arthritis