Referral of the month - polymyalgia rheumatica
Consultant rheumatologist Dr Joel David discusses the referral of a lady with suspected polymyalgia.
Thank you for seeing this 70-year-old lady with symptoms suggesting polymyalgia, but who has not responded in the usual way to steroids.
The story is that she presented six weeks ago with a two-month history of progressively painful and stiff shoulders and hips. The symptoms sometimes woke her and were definitely worse first thing in the morning. There were no other symptoms, apart from the fact that she had lost a little weight. There were no temporal headaches.
I arranged an FBC and an ESR. The FBC showed only a mild normochromic, normocytic anaemia but the ESR was markedly elevated at 64. While awaiting the blood results, I suggested she stop her statin in case this was the culprit, which I doubted, because she has been on it for years.
When she returned, she was no better for having stopped her statin. On this basis I diagnosed polymyalgia rheumatica and started her on prednisolone 5mg tds. Disappointingly, she returned a week later saying there was only very marginal improvement.
• 1987 – mild asthma.
• 2004 – angina.
• 2008 – OA knees.
• Continues to smoke 10 cigarettes per day.
• Soluble aspirin 75mg/day.
• Atenolol 100mg/day.
• Salbutamol inhaler prn.
• Simvastatin 40mg/day.
I’d be very grateful for your expert assessment here. I’ve always understood that a full response to one week of 15mg prednisolone is diagnostic of PMR, so I assume this casts uncertainty on the diagnosis. Or is there an argument for trying the steroids for longer, or at a higher dose? If other diagnoses are a possibility, I’d appreciate your advice regarding appropriate investigations.
Many thanks for inviting me to review this patient.
In support of the diagnosis of polymyalgia rheumatica, your patient is in the right age bracket and women are generally more commonly affected by this disorder than men (a ratio of 3:1). Polymyalgia is more usually of sudden onset rather than a two-month progressive development, but the symptoms being worse at night and first thing in the morning are rather typical of polymyalgia.
I tend to use the CRP more than the ESR as a measure of acute phase and inflammation. The reason is that CRP, when it is elevated, is always indicative of pathology (inflammation, infection or neoplasia). ESR can be elevated because of anaemia, older age or benign monoclonal gammopathy.
The ESR of 64 is high, and if her reading had previously been normal then this would be significant. My usual practice is to start steroid at 15mg and to give it all at once as a single dose, first thing in the morning. This tends to work better and is probably associated with fewer side-effects and adrenal suppression. Usually, this dose would be sufficient to achieve a good clinical response. Very occasionally 20mg is required. If the patient has underlying OA, the degenerative joint symptoms may be the reason for the apparent lack of response to the steroid.
With regard to the statin, it is extremely unlikely that this would be the cause of her symptoms. Statins can very rarely cause muscle pains and myositis. They would not be associated with an acute phase. In a small percentage of patients the CPK may be elevated. The symptoms of muscle pain after years of using the statin would make this an unlikely cause.
The red flags in this lady’s case are that she continues to be a smoker and has had a somewhat inadequate response to steroid (albeit in split dosage). I would recommend that she have a chest X-ray and I would probably have done this on presentation. Her symptoms could be indicative of paraneoplastic disease. The elevated ESR and more progressive, rather than sudden, onset at presentation would suggest that she requires an immunoglobulin electrophoresis and urine testing for light chains – I am thinking of myeloma as a differential diagnosis.
In my experience, when polymyalgia does not respond as you would expect it to, the index of suspicion for other disorders, in particular neoplasia, must be high. The other diagnosis you would need to think about in an elderly lady with a progressive onset of stiffness is thyroid disease. Although weight loss is more typical of hyperthyroidism, it can occur with an underactive thyroid as well.
With regard to the treatment of polymyalgia, in addition to steroids, which, as I’ve said, would be a single dose in the morning, I would add a PPI as she is also on aspirin and the incidence of GI toxicity with aspirin and steroid together is increased.
I would also give her bone protection with calcium and vitamin D and a bisphosphonate. The bisphosphonate would be a further reason to add the PPI. For straightforward polymyalgia, uncomplicated by giant cell arteritis, 15mg of prednisolone is usually sufficient.
The duration of treatment will be around two-and-a-half to five years. I would reduce the dose extremely cautiously. In this way, you will avoid the inevitable flare-ups that occur with too rapid a reduction. This will have the consequence of dosage increase and the area under the curve would be greater – cumulative toxicity of steroid will be higher if the dose needs to be put up frequently to accommodate the flare-ups. So, my usual practice is to reduce from 15mg by 1mg per month down to 9mg, and thereafter by 1mg every three to four months.
The inflammatory rheumatic diseases, such as polymyalgia and rheumatoid arthritis, are now known to have a significantly increased risk of cardiovascular disease (independent of steroid use) commensurate with that of diabetes. This lady has already suffered from angina and continues to smoke, and therefore she has a number of risk factors for ischaemic heart disease. The continued use of a statin and the addressing of other risk factors such as weight, hyperuricaemia and hypertension are very important. Smoking cessation is essential for her.
There is a very small subset of patients with polymyalgia rheumatica who seem to require higher doses of steroid for longer periods in order to achieve symptom control. In these patients, the use of steroid-sparing therapy may be considered. My preference would be for methotrexate, but azathioprine and leflunomide have equally been used. In these situations, it would also be important to think about a polymyalgic presentation of rheumatoid arthritis or subclinical large vessel vasculitis. Looking for synovitis in the wrists and the metacarpophalangeal joints using ultrasound may be very important in this case and would support the use of methotrexate as the disease-modifying drug.
Please do get in touch if your patient fails to settle promptly.
Dr Joel David FRCP, Consultant rheumatologist
• Uncomplicated polymyalgia rheumatica usually presents with sudden onset of pain and stiffness in the shoulder and pelvic girdle, worse first thing in the morning.
• A raised CRP is often more useful than a raised ESR.
• Use a single dose of prednisolone each morning, usually 15mg.
• The average duration of steroid use is two-and-a-half to five years, therefore reduce slowly.
• Use bone-sparing therapy and GI protection with steroids to minimise side-effects.
• Bear in mind the differential diagnosis.
• Be aware of red flags such as constitutional upset, smoking, visual loss, poor steroid responsiveness.
Dr Joel David is a consultant rheumatologist at Oxford University Hospitals NHS Foundation Trust.