CHAPTER 24: PMR & GCA
The two (related) topics of this time are
1) POLYMYALGIA RHEUMATICA (PMR).
2) GIANT CELL ARTERITIS (GCA). GCA is also known as temporal arteritis.
50% of patients with GCA develop PMR too.
20% of patients with PMR develop GCA too.
Here are a few THMs on PMR or polymyalgia rheumatica.
PMR occurs almost exclusively in adults over age 50. Peak incidence is between ages 70 & 80. Women are affected 2 to 3 times more commonly than men. Sometimes more than one family member is afflicted.
One should suspect PMR if aches and stiffness are present in at least two of the following three locations-
1) Shoulders or proximal arms
2) Hips or proximal thighs
3) Neck or torso
Do remember that symptoms are bilateral and symmetrical.
The symptoms are usually insidious in onset but can be startingly abrupt.
The morning stiffness in the above locations lasts at least 30 minutes. It can be severe enough to cause difficulty in arising from the bed.
The term ‘gel phenomenon’ refers to stiffness after inactivity and is often severe in PMR causing symptoms all day in the sedentary elderly.
Clinical findings include
1) Tenderness over shoulder and hip joints due to synovitis.
2) Inability to abduct shoulders past 90 degrees. This often leads to a mistaken diagnosis of ‘bilateral frozen shouder’.
3) Mild swellings of hands and feet.
Patients of PMR often have systemic symptoms like low grade fever, anorexia and malaise. Unfortunately, often patients with such symptoms and aches receive a diagnosis of depression.
There are no pathognomonic features and diagnostic tests for PMR. The typical lab finding is high ESR, often above 100. However, in about 10% of cases of PMR, the ESR will be below 40.
High CRP (more than 5) may be a more sensitive test.
Once you suspect PMR on clinical grounds and high ESR and/or high CRP, the next step in confirming diagnosis is giving a therapeutic trial of oral steroids.
Low dose prednisolone, 10 to 20 mg/d, gives significant relief within 2 or 3 days. If it does not, the diagnosis should be doubted. It is important to give a low dose as a regular dose of 1mg/kg may relieve other pain causing syndromes.
Once the diagnosis of PMR is made one should continue the low dose steroid for weeks to months. Tapering should be attempted when symptoms and ESR show significant declines. Recurrence of symptoms is common while tapering and many patients require steroids for two years plus.
Those 20% of PMR patients who have coexisting GCA will not show relief of GCA symptoms with low dose steroids.
Here are a few THMs on Giant Cell Arteritis. GCA is also known as temporal arteritis as temporal arteries are the most commonly affected vessels.
As mentioned before, GCA can occur isolated or in association with PMR. Nearly 50% of patients with GCA also have PMR.
GCA is a systemic inflammation of medium and large arteries. Apart from the involvement of temporal arteries (which causes headache), clinically important involvement can occur in other cranial arteries (causing blindness, strokes, scalp infarction, tongue infarction, jaw claudication) and in the aorta and it’s branches (causing aortic aneurysms, arm claudication due to subclavian stenosis).
The commonest presenting symptoms are temporal headache and fever/malaise/anorexia/weight loss. The headache may be unilateral or bilateral.
A dreaded symptom is blindness due to ischaemic optic neuropathy.
On examination, the temporal artery on the side of headache may be swollen and tender. This finding is more common in early disease.
Typical lab findings are high ESR and high CRP (as in PMR) and often mild anaemia and high alkaline phosphatase.
A Doppler ultrasound of the temporal artery may reveal flow abnormalities and intimal thickening.
Confirmation of diagnosis is NOT made by a therapeutic trial with steroids but by a temporal artery biopsy.
Some experts however do not see the need for biopsy if typical symptoms of PMR are also present.
While isolated PMR may be treated by a confident family physician, any suspected case of GCA must be referred to a rheumatologist. Treatment involves oral steroids at a dose of 1mg/kg/d. Aspirin must be co-prescribed to prevent infarcts. Treatment is often for several months or years.
THINK OF GCA when
1) an elderly person comes with fever, weight loss and temporal headache.
2) an elderly person complains of decline in vision and headache.
3) an elderly person with systemic symptoms shows up a thoracic aortic aneurysm and has a very high ESR.
4) an elderly person has been diagnosed by someone else as migraine (which does not start in old age)!