Polymyalgia Rheumatica
Summary
Polymyalgia Rheumatica (PMR) is the most common inflammatory rheumatic disease of the elderly. It is characterized by severe bilateral pain and stiffness in the shoulder and pelvic girdles. It is almost exclusively a disease of those >50 years old. It has a strong association with Giant Cell Arteritis (GCA) (15-20% of PMR patients develop GCA; 50% of GCA patients have PMR). The hallmark of management is a dramatic response to low-dose corticosteroids (15mg Prednisolone), usually within 72 hours. [1,2]
Clinical Pearls
The "Gel Phenomenon": Stiffness is profound in the morning (>45 mins, often hours) and after periods of inactivity. Patients describe it as "gelling" up.
SNOOP for Red Flags: In any elderly patient with new "pain", rule out Metastasis, Myeloma, and Infection. If the ESR is normal, be very wary of making a PMR diagnosis (though rare cases exist).
Steroid Response Test: If a patient with suspected PMR does not report a 70% improvement within 1 week of starting Prednisolone 15mg, the diagnosis is incorrect. Revisit differentials (e.g., Fibromyalgia, Rotator Cuff, OA).
Demographics
- Prevalence: 0.7% in people >50.
- Age: Peak 70-80 years. NEVER seen in less than 50s.
- Gender: F:M = 2:1.
- Genetics: HLA-DR4 association.
Mechanism
- Not a myositis (muscle inflammation).
- It is a Synovitis and Bursitis of proximal joints.
- Shoulder: Subacromial/Subdeltoid bursitis.
- Hip: Trochanteric/Iliopsoas bursitis.
- Systemic inflammation (IL-6 driven) causes the constitutional symptoms.
| Condition | Pain | Weakness | CK | ESR |
|---|---|---|---|---|
| PMR | Severe | None (pain limits effort) | Normal | High |
| Polymyositis | Minimal | Severe (Proximal) | High | High |
| Fibromyalgia | Widespread | None | Normal | Normal |
| Hypothyroidism | Aches | Mild proximal | High | Normal |
| RA (Elderly onset) | Peripheral | None | Normal | High |
Core Criteria (BSR Guidelines)
- Age > 50.
- Duration > 2 weeks.
- Bilateral Shoulder and/or Pelvic girdle pain.
- Morning Stiffness > 45 minutes.
- Raised Inflammatory Markers (ESR/CRP).
Functional Impact
Check for GCA Symptoms (Critical)
Essential
- ESR / CRP: Elevated in >95%. (e.g., ESR > 40).
- CK: Normal (Essential to exclude myositis).
- FBC: Normocytic anaemia of chronic disease. Platelets may be high (reactive).
- TFTs: Exclude hypothyroidism.
- Calcium/ALP: Exclude bone mets (ALP raised) or osteomalacia.
- Protein Electrophoresis: Exclude Myeloma.
Imaging
- Ultrasound Shoulders: Shows bilateral subacromial bursitis (supports diagnosis but usually clinical).
Management Algorithm
SUSPECTED PMR
(Age >50, ESR High, Stiffness)
↓
RULE OUT GCA & RED FLAGS
┌─────────┴─────────┐
GCA PRESENT NO GCA
(High Dose Steroid) ↓
START STEROIDS
• **Prednisolone 15mg** OD
• **PPI** (Gastroprotection)
• **Bone Protection** (VitD/Ca)
↓
REVIEW AT 1 WEEK
┌──────────┴──────────┐
RESPONSE NO RESPONSE
(Dramatic) (Review Dx)
↓
TAPER REGIMEN
• 15mg for 3 weeks
• Drop to 12.5mg for 3 weeks
• Drop to 10mg for 4-6 weeks
• Then slow taper by 1mg every 4-8 weeks
Bone Protection (BSR Guidelines)
- All patients >65 or with previous fragility fracture should start Bisphosphonate (Alendronic Acid) + Calcium/Vitamin D.
- Younger patients need DEXA scan to guide decision.
Steroid Sparing Agents
- Methotrexate: Added if frequent relapses or inability to taper steroids.
- Giant Cell Arteritis: Monitor headache at every visit.
- Steroid Side Effects:
- Diabetes.
- Osteoporosis.
- Weight gain / Cushingoid features.
- Hypertension.
- Skin thinning.
- Course: Self-limiting condition, usually burns out after 1-2 years.
- Relapse: Common (50% of patients). Occurs when tapering too fast. Requires stepping back to previous effective dose.
Key Guidelines
| Guideline | Organisation | Key Recommendations |
|---|---|---|
| PMR | BSR (2010) | Diagnostic criteria and tapering schedule. |
| GCA | BSR (2020) | Urgent referral pathways. |
Landmark Evidence
1. Dasgupta et al (Rheumatology 2010)
- BSR guidelines establishing the "15mg" rule. Doses >20mg are unnecessary for pure PMR and increase toxicity. Doses less than 10mg often insufficient for induction.
What is PMR?
"Poly" means many, "Myalgia" means muscle pain. It is an inflammatory condition that causes severe stiffness and pain, mainly in the shoulders and hips. It happens in the immune system attacking the soft tissues around the joints.
Why do I feel so old in the morning?
This is the "gelling" effect. While you sleep, the inflammatory fluids settle in the joints, making them stiff like set jelly. It takes about an hour of movement to "warm them up" and get moving.
The Miracle Cure (Steroids)
We treat this with Prednisolone (a steroid). It works incredibly well. Most patients feel 100% better within 2-3 days – often describing it as a miracle.
The Catch
Although you feel better quickly, the disease takes 1-2 years to burn out properly. We have to keep you on a low dose of steroids for that whole time, slowly reducing it. If we stop too soon, the pain will come back.
Primary Sources
- Dasgupta B, et al. BSR and BHPR guidelines for the management of polymyalgia rheumatica. Rheumatology. 2010.
- Dejaco C, et al. 2015 EULAR/ACR recommendations for the management of polymyalgia rheumatica. Ann Rheum Dis. 2015.
- Buttgereit F, et al. Polymyalgia Rheumatica and Giant Cell Arteritis. JAMA. 2016.
Common Exam Questions
- Diagnosis: "Bilateral shoulder pain, morning stiffness, ESR 80?"
- Answer: PMR.
- Safety: "What to check before starting steroids?"
- Answer: GCA symptoms (Headache/Visual). Also Glucose/BP.
- Investigation: "Test to rule out Polymyositis?"
- Answer: Creatine Kinase (CK).
- Treatment: "Starting dose of Prednisolone?"
- Answer: 15mg. (40-60mg would be for GCA).
Viva Points
- PMR vs RA: Elderly onset RA can look just like PMR. Look for small joint involvement (MCPs) and RF/CCP antibodies.
- Normal ESR PMR: Rare but exists. Diagnosis relies on classic clinical features and rapid steroid response.
Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. Clinical decisions should account for individual patient circumstances. Always consult appropriate specialists.