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Polymyalgia rheumatica PMR and Giant cell arteritis GCA

Dr Rajesh Varma

Definitions

Polymyalgia rheumatica (PMR) is a chronic systemic rheumatic inflammatory disease characterized by
aching and morning stiffness in the neck, shoulder, and pelvic girdle.

Giant cell arteritis (GCA) is a type of chronic vasculitis characterized by granulomatous inflammation in the walls of medium and large arteries.
The annual incidence of GCA in the UK is about 20 per 100,000 people.

Giant cell arteritis is associated with 15–20% of PMR cases.

Risk factors for GCA

Mean age of onset age 70y

Female gender

White ethnicity

Giant cell arteritis and polymyalgia rheumatica often occur together and may share the same pathophysiology

Risk factors for PMR

  • Older age Age > 65y

  • Female gender: lifetime risk of 2.4% for women and 1.7% for men.

  • Northern European ancestry

  • Infection
    peaks observed in winter and associated mycoplasma, chlamydia pneumonia, and parvovirus B19 infections

Complications of PMR

  • Giant cell arteritis (GCA)

  • Complications of long-term corticosteroid treatment.

Complications of GCA

  • Vision loss.

  • Large artery complications (such as aortic aneurysm, aortic dissection, large artery stenosis, and aortic regurgitation).

  • Cardiovascular disease.

  • Peripheral neuropathy.

  • Depression.

  • Confusion and encephalopathy.

  • Deafness.

Diagnosis of PMR

  1. Age > 50y

  2. Bilateral shoulder and/or pelvic girdle aching lasting more than 2 weeks.

  3. Morning stiffness (for more than 45 minutes).

  4. Evidence of an acute phase response.

  5. Other more general symptoms, such as low-grade fever, fatigue, anorexia, weight loss, or depression.

Diagnosis of GCA

  1. Age >50y

  2. New onset unilateral headache in the temporal area

  3. Temporal artery tenderness, thickening, or nodularity.

  4. Systemic features such as fever, fatigue, anorexia, weight loss, and depression.

  5. Features of PMR (bilateral upper arm/pelvic girdle pain and stiffness)

  6. Scalp tenderness, especially over the temporal and occipital arteries

  7. Intermittent jaw claudication.

  8. Visual disturbances.

  9. Neurological features (such as mononeuropathy or polyneuropathy of arms or legs, transient ischaemic attack, stroke).

  10. Peripheral arthritis and distal swelling with pitting oedema.

  11. Respiratory tract symptoms such as cough, sore throat, and hoarseness.

Referral to a rheumatologist

  1. To diagnose GCA, refer suspected GCA URGENTLY to secondary care for a temporal artery biopsy
    If there is suspected GCA with visual impairment — arrange an urgent (same day) assessment by an ophthalmologist

  2. Diagnostic uncertainty for PMR, such as:
    Atypical features of PMR, such as no evidence of an acute phase response and no clear alternative diagnosis.
    Poor response to corticosteroids (48hr for GCA or 7 days for PMR).
    Inability to reduce corticosteroids at reasonable intervals without causing relapse.
    Corticosteroids are required for more than 2 years

Required primary care investigations

Do not delay initiation of treatment for suspected GCA while awaiting secondary care specialist review and temporal artery biopsy

For a working diagnosis of PMR:

  1. Identifying core features of the condition (clinical features and raised acute phase response)

  2. Excluding conditions that mimic PMR (such as GCA, rheumatoid arthritis and fibromyalgia)

  3. Positive response to oral corticosteroids (clinical improvement by 7 days, normalization of inflammatory markers within 4 weeks).

Arrange the following tests in all people with suspected PMR to rule out other conditions before starting corticosteroids:
full blood count, urea and electrolytes, liver function tests, Erythrocyte sedimentation rate (ESR):C-reactive protein (CRP):
calcium
protein electrophoresis
thyroid stimulating hormone
creatine kinase
rheumatoid factor
Urine dipstick urinalysis.

Consider the following tests depending on the clinical features:
a urine specimen for Bence Jones protein
blood tests for anti-nuclear antibody and anti-cyclic citrullinated peptide antibody
chest X-ray.

Interval monitoring of PMR and GCA in primary care

For cases of GCA and PMR, assess ESR, BP and glucose 3-monthly, with FBC and U&E monitoring if clinically indicated.

Treatment of PMR and GCA

  1. For GCA, whilst awaiting specialist review, initiate oral prednisolone
    For PMR, assuming PMR is the most likely diagnosis (core clinical features, acute phase response, excluded other conditions such as GCA and Rheumatoid Disease), then initiate oral prednisolone

  2. Initial treatment doses of oral predinoslone
    oral prednisolone 60mg for visual-GCA
    oral prednisolone 40-60mg daily for non-visual GCA
    oral prednisolone 15mg daily for PMR

  3. In cases of PMR, assess the person's response to prednisolone in 7 days,
    In cases of GCA, assess the person's response to prednisolone within 48 hours

    If response to prednisolone is poor, seek specialist advice and consider an alternative diagnosis.

  4. In cases of GCA, start Aspirin 75mg and gastroprotection with a PPI, unless there are contraindications.

  5. Aim to gradually reduce the dose of corticosteroids when symptoms are fully controlled: use a regimen of dose reduction that avoids relapse or risks acute adrenal insufficiency.

  6. For PMR and GCA, treatment for 1–2 years is often required, but people may require low doses of corticosteroids for several years thereafter.

Assessing for, and manage, symptoms of

  • Relapse of PMR or GCA: responds to restarting or increasing the dose of systemic corticosteroids
    For cases of GCA, If relapse occurs (visual disturbance, jaw claudication, headaches),
    increase the dose of prednisolone and seek advice from a specialist regarding further management
    (and same day ophthalmologist assessment if relapse is new onset visual disturbance)

  • Steroid-related adverse effects

  • Osteoporosis prophlyaxis

Differential diagnosis of PMR

  • Degenerative disorders

  • Cervical and lumbar spondylosis

  • Osteoarthritis — commonly involves hands, hips, knees, and spine. Pain improves with rest and increases with joint use and at the end of the day.

  • Bilateral adhesive capsulitis (frozen shoulder) and rotator cuff disorders

  • Endocrine disorders:Thyroid disease, hyperparathyroidism

  • Infection: Viral illness, Chronic osteomyelitis, Tuberculosis, Infective endocarditis

  • Inflammatory disorders:
    Rheumatoid arthritis, Spondyloarthropathy, Remitting seronegative symmetric synovitis, Polymyositis/dermatomyositis- increase CK, painful muscle weakness
    Systemic lupus erythematosus

  • Cancer: Multiple myeloma, Acute leukaemia, Lymphoma, Lung carcinoma

  • Drug-related adverse effects, including:
    Myositis or myalgia due to statins — increased CK.
    PMR-like syndrome due to quinidine.

  • Osteomalacia

  • Fibromyalgia

  • Chronic fatigue syndrome

Differential diagnosis of GCA

  • Herpes zoster.

  • Cluster headache or migraine.

  • Acute angle closure glaucoma.

  • Retinal transient ischaemic attacks and embolic visual deficits.

  • Temporomandibular joint pain, sinus disease, and ear problems.

  • Cervical spondylosis or other upper cervical spine disease.

  • Ankylosing spondylitis.

  • Myeloma with cervical or cranial deposits, or other cranial malignancy.

  • Serious intracranial pathology, such as infiltrative retro-orbital or base of skull lesions.

  • Connective tissue disease.