Musculoskeletal

Polymyalgia rheumatica and giant cell arteritis

Clinical Overview and When to Suspect PMR and GCA

— ~40–50% of GCA patients have PMR symptoms; ~15–20% of PMR patients eventually develop GCA.

— Both share elevated acute-phase reactants and dramatic glucocorticoid responsiveness.

— Hallmark symptoms: new-onset headache, scalp tenderness, jaw claudication, visual disturbance (amaurosis fugax, diplopia, permanent vision loss from anterior ischemic optic neuropathy).

— Constitutional symptoms (fever, weight loss, fatigue) are common; GCA is a leading cause of FUO in the elderly.

— Patient >50 with new bilateral shoulder/hip stiffness worse in the morning → think PMR.

— Patient >50 with new headache + ESR/CRP markedly elevated → think GCA until proven otherwise.

— Sudden monocular vision loss in an elderly patient + jaw pain with chewing → GCA emergency.

Polymyalgia rheumatica (PMR) and giant cell arteritis (GCA) are overlapping inflammatory disorders of adults ≥50, peaking in the 70s–80s, with strong female predominance (2–3:1) and a striking association with Northern European ancestry.

PMR = symmetric proximal shoulder and hip girdle pain and stiffness with morning stiffness >45 minutes, lasting ≥2 weeks, without true weakness on exam.

GCA (temporal arteritis) = large- and medium-vessel granulomatous vasculitis, classically of cranial branches of the external carotid, but also aorta and its primary branches.

When to suspect in your Step 3 outpatient or ED stem:

Step 3 management: If GCA is even reasonably suspected (especially with visual or neurologic symptoms), start high-dose glucocorticoids immediately—do not wait for temporal artery biopsy. Diagnostic yield of biopsy persists for ~2 weeks after steroid initiation.

Board pearl: GCA is the only vasculitis where empiric treatment precedes confirmatory testing routinely on the exam—because vision loss, once established, is typically permanent and bilateral within days if untreated.

Presentation Patterns and Key History

— Bilateral aching and stiffness in the shoulders (70–95%), hip girdle/proximal thighs (50–70%), and neck.

— Morning stiffness ≥45 minutes, often >1 hour; gelling after inactivity.

— Difficulty rising from a chair, combing hair, donning a coat.

— Onset typically subacute over days to a few weeks; bilateral and symmetric from the start.

— Constitutional: low-grade fever, malaise, anorexia, depression, 10% weight loss.

— No true muscle weakness—pain limits effort, but strength testing (when tolerated) is preserved. CK is normal.

— New-onset headache (often temporal, unilateral, throbbing or boring) in >2/3.

— Scalp tenderness—pain combing hair or laying head on pillow.

— Jaw claudication (jaw fatigue with chewing)—highest positive likelihood ratio (~4–6) for GCA.

— Visual symptoms: transient monocular vision loss (amaurosis fugax), diplopia, blurred vision; permanent vision loss in 15–20% untreated.

— Tongue claudication or tongue/scalp necrosis (rare but pathognomonic).

— Arm claudication, asymmetric blood pressures, bruits, thoracic aortic aneurysm/dissection (late complication, 17× baseline risk).

— May lack classic cranial symptoms—suspect when persistent inflammation + constitutional symptoms in elderly.

— Duration and bilaterality of stiffness; response to OTC NSAIDs (typically poor in PMR).

— Headache character, jaw symptoms with chewing, transient vision changes.

— Functional impact: dressing, hair care, rising from chair.

PMR symptom pattern:

GCA symptom pattern (cranial phenotype):

Large-vessel GCA phenotype:

Key history elements to elicit:

Key distinction: PMR causes pain that mimics weakness (can't lift arms because of pain); inflammatory myopathy (polymyositis) causes objective proximal weakness with normal-to-mild pain and elevated CK. Confusing these costs you the question. PMR has normal CK, normal EMG, normal muscle biopsy.

Board pearl: Any patient >50 with new headache + ESR >50 deserves a GCA workup—this triad alone is one of the highest-yield triggers on Step 3.

Physical Exam Findings and Vascular Assessment

— Restricted active range of motion of shoulders and hips due to pain, especially abduction past 90°.

— Passive ROM often preserved or only mildly limited—useful distinguishing feature.

— Tenderness over deltoid insertion, trochanteric bursae, cervical paraspinals.

— No synovitis of small joints typically, though mild peripheral arthritis (knees, wrists), carpal tunnel, or distal extremity pitting edema (RS3PE-like) can occur in ~25%.

— Strength is intact when pain is controlled; no muscle atrophy.

— Temporal artery abnormalities: tender, thickened, beaded, nodular, or pulseless temporal artery. A normal-feeling temporal artery does not rule out GCA.

— Scalp tenderness on palpation; rarely visible scalp necrosis.

— Funduscopy in acute vision loss: pale, swollen optic disc (anterior ischemic optic neuropathy, AION) with flame hemorrhages; cherry-red spot in central retinal artery occlusion.

— Cranial nerve palsies, particularly CN VI (diplopia).

— Asymmetric brachial blood pressures (>10–15 mmHg difference).

— Diminished or absent peripheral pulses (radial, axillary).

— Bruits over subclavian, axillary, carotid arteries.

— Listen for aortic regurgitation murmur (aortic root involvement).

PMR exam:

GCA exam — cranial:

GCA exam — large-vessel/systemic:

CCS pearl: In a CCS case of suspected GCA, your physical exam order set should include: bilateral BP measurement, palpation of temporal arteries, careful funduscopy, peripheral pulse exam, and auscultation of subclavian/carotid arteries. Skipping the vascular exam misses large-vessel disease.

Board pearl: Jaw claudication + abnormal temporal artery on palpation has the highest specificity for GCA among physical findings. Vision loss in GCA is typically sudden, painless, and monocular, evolving to the contralateral eye within 1–2 weeks if untreated—a true ophthalmologic emergency.

Diagnostic Workup — Initial Labs and Inflammatory Markers

— ESR typically >50 mm/hr in both PMR and GCA; often >100 in GCA.

— CRP is more sensitive and rises/falls faster than ESR; >2.45 mg/dL is a common threshold.

— Both elevated → high pretest probability; both normal → makes PMR/GCA unlikely but doesn't fully exclude (4–20% of GCA can have normal ESR, particularly if on prior steroids).

— Always order both—they can be discordant.

— Normocytic anemia of chronic disease (Hgb 10–12).

— Thrombocytosis (often >400K)—a useful clue.

— Mildly elevated alkaline phosphatase (hepatic involvement, ~30%).

— Normal CK, aldolase, TSH — rule out myopathy and hypothyroid mimics.

— Normal or negative: ANA, RF, anti-CCP (helps exclude RA, lupus).

— CBC, CMP, ESR, CRP, TSH, CK, RF, anti-CCP, vitamin D, urinalysis, SPEP (rule out myeloma in elderly with bone pain and elevated ESR).

— Same panel plus urgent ophthalmology consult if visual symptoms, and arrange temporal artery biopsy within 1–2 weeks of steroid initiation.

Cornerstone labs:

Supportive labs:

Initial workup checklist for suspected PMR:

Initial workup checklist for suspected GCA:

2012 EULAR/ACR PMR classification criteria (age ≥50, bilateral shoulder pain, elevated CRP/ESR required, plus points for): morning stiffness >45 min, hip pain/limited motion, absent RF/anti-CCP, absent peripheral synovitis. ≥4 points classifies as PMR.

Step 3 management: Always order both ESR and CRP, plus CK and TSH before committing to a PMR diagnosis. Don't anchor on PMR in a patient with normal inflammatory markers—reconsider statin myopathy, hypothyroidism, late-onset RA, or paraneoplastic syndromes.

Board pearl: Platelet count >400K in an elderly patient with new headache nudges you strongly toward GCA—an underappreciated but high-LR finding.

Diagnostic Workup — Confirmatory and Advanced Studies

— Gold standard for GCA diagnosis.

— Obtain a long segment (≥1–2 cm) because of skip lesions.

— Unilateral biopsy sensitivity ~85%; contralateral biopsy adds ~5%.

— Do not delay steroids awaiting biopsy—pathology remains positive for up to 2–4 weeks after steroid initiation.

— Histology: granulomatous inflammation, multinucleated giant cells, fragmentation of internal elastic lamina, intimal hyperplasia. Giant cells are supportive but not required.

— Temporal artery ultrasound: "halo sign" (hypoechoic wall thickening), non-compressible artery. Sensitivity ~55–75%; highly operator-dependent.

— MRI/MRA of cranial arteries: wall thickening and enhancement.

— CTA or PET-CT of aorta and great vessels: detects large-vessel GCA—indicated for atypical presentation, persistent inflammation despite steroids, or new bruits/pulse asymmetry.

— No specific confirmatory test—clinical diagnosis supported by elevated ESR/CRP and dramatic response to low-dose prednisone (15–20 mg/day) within 3–7 days.

— Shoulder/hip MRI or US can show subacromial-subdeltoid bursitis, biceps tenosynovitis, hip trochanteric bursitis—highly characteristic but not required.

— Baseline and follow-up imaging (CTA or MRA) for confirmed GCA patients—rising recognition of aortic aneurysm risk, particularly thoracic.

Temporal artery biopsy (TAB):

Vascular imaging (increasingly first-line in Europe, complementary in US):

For PMR diagnosis:

Aortic surveillance:

Key distinction: Lack of response to 15–20 mg prednisone within a week should make you doubt the PMR diagnosis. Late-onset spondyloarthritis, RS3PE, malignancy-associated syndromes, and statin myopathy can mimic PMR but respond poorly.

Board pearl: A negative TAB does not rule out GCA—if clinical suspicion remains high, continue steroids and pursue large-vessel imaging. The decision to treat is clinical first, pathologic second.

Risk Stratification and Management Logic

— Scenario 1 — Isolated PMR (no cranial/visual symptoms):

Start prednisone 15–20 mg PO daily. Expect dramatic relief within 24–72 hours. Failure to improve within a week should prompt reconsideration of diagnosis.

— Scenario 2 — GCA without vision loss or threatened vision:

Start prednisone 40–60 mg PO daily (≈1 mg/kg, max 60 mg). Arrange TAB within 1–2 weeks. Do not wait for biopsy.

— Scenario 3 — GCA with vision loss, amaurosis fugax, or diplopia:

IV methylprednisolone 500–1000 mg daily × 3 days, then transition to oral prednisone 60 mg daily. Urgent ophthalmology consult. Treatment may not restore lost vision but prevents fellow-eye involvement.

— High relapse risk in GCA: female sex, very high baseline ESR/CRP, early steroid taper, large-vessel involvement.

— Long-term cardiovascular risk: GCA increases risk of thoracic aortic aneurysm/dissection 17-fold and abdominal aortic aneurysm 2-fold—warrants ongoing imaging surveillance (CTA or MRA every 2–3 years, debated frequency).

— Low-dose aspirin (81 mg) is controversial; some experts add it in GCA to reduce ischemic events, though evidence is observational.

— Steroid-sparing agents (tocilizumab, methotrexate) introduced for relapse, intolerance, or to limit cumulative steroid exposure.

— Bone protection from day 1: calcium, vitamin D, bisphosphonate for anyone on prednisone ≥7.5 mg for ≥3 months expected.

Three clinical scenarios drive initial management:

Risk stratification for relapse and complications:

Adjunctive therapy decisions:

CCS pearl: In a CCS GCA case, your simultaneous orders are: high-dose steroid + ophthalmology consult + ESR/CRP + CBC + CMP + bone density referral + PPI (for GI prophylaxis if high-risk) + calcium/vitamin D + low-dose aspirin (case-by-case) + temporal artery biopsy scheduled. Steroids first, always.

Pharmacotherapy — Glucocorticoids and Steroid-Sparing Agents

— PMR: prednisone 15–20 mg/day, single morning dose. Continue 2–4 weeks until full symptom remission and normalization of ESR/CRP, then taper.

— GCA, no vision threat: prednisone 40–60 mg/day × 2–4 weeks until clinical/lab remission, then taper.

— GCA with vision loss or amaurosis: IV methylprednisolone 1 g/day × 3 days → oral prednisone 60 mg/day.

— PMR taper: reduce by 2.5 mg every 2–4 weeks until 10 mg, then 1 mg every 1–2 months. Typical duration 1–2 years, some require longer.

— GCA taper: reduce by 10 mg every 2 weeks to 20 mg; then 2.5 mg every 2–4 weeks to 10 mg; then 1 mg every 1–2 months. Typical duration 2–3 years.

— FDA-approved for GCA (2017) based on GiACTA trial—reduces cumulative steroid exposure and prolongs remission.

— Dosing: 162 mg SC weekly (or every 2 weeks). Allows faster steroid taper.

— Indications: relapsing GCA, steroid-dependent, or intolerant to steroids (uncontrolled diabetes, severe osteoporosis).

— Monitor for: infection (TB screen before initiation), neutropenia, transaminitis, GI perforation (especially in diverticular disease), hyperlipidemia. CRP is suppressed by tocilizumab—do not use it to monitor disease activity on tocilizumab.

— Modest steroid-sparing effect in PMR and GCA; 7.5–15 mg weekly with folic acid. Reasonable in relapsing or steroid-intolerant patients when tocilizumab is unavailable.

Glucocorticoid dosing summary:

Taper strategies:

Tocilizumab (IL-6 receptor antagonist):

Methotrexate:

Step 3 management: Initiate bone-protective therapy at the same visit you start prednisone—calcium 1000–1200 mg/day, vitamin D 800–1000 IU/day, and bisphosphonate (alendronate or risedronate) if anticipated prednisone ≥7.5 mg/day for ≥3 months, or per ACR 2017 GIOP guidelines based on fracture risk.

Board pearl: On tocilizumab, inflammatory markers can be falsely normal—monitor with symptoms and vascular imaging, not CRP.

Adjunctive Management and Procedural Considerations

— Low-dose aspirin (81 mg) considered in GCA for ischemic event prevention (stroke, vision loss). Recommendations vary; reasonable for most GCA patients without bleeding contraindications, though high-quality RCT data are lacking.

— Outpatient surgical procedure under local anesthesia, typically performed by vascular or ophthalmology surgery.

— Long segment (1.5–2 cm) required due to skip lesions.

— Complications: minor bleeding, infection, scarring; rare facial nerve frontal branch injury if biopsy too anterior.

— Should not delay steroid initiation—treat first, biopsy within 1–2 weeks.

— Update pneumococcal (PCV20 or PCV15+PPSV23), influenza, shingles (recombinant zoster Shingrix), COVID-19 vaccines ideally before starting immunosuppression—Shingrix can be given on steroids but optimal before tocilizumab.

— PJP prophylaxis (TMP-SMX) considered for sustained prednisone ≥20 mg/day for >4 weeks.

— TB screening (IGRA) prior to tocilizumab.

— PPI for patients on high-dose steroids with additional risk factors (concurrent NSAIDs, anticoagulation, prior PUD, age >65 + multiple risk factors).

— Anticipate steroid-induced hyperglycemia—check fasting glucose, HbA1c at baseline and periodically; many patients require new or intensified diabetes therapy.

— Monitor BP and treat new steroid-induced hypertension.

— Confirmed thoracic aortic aneurysm follows standard size and growth thresholds for surgical referral (≥5.5 cm thoracic, or growth >0.5 cm/year, or symptomatic).

Aspirin:

Temporal artery biopsy as a procedure:

Vaccination and infection prophylaxis:

GI prophylaxis:

Glycemic and BP management:

Aortic aneurysm management:

CCS pearl: A well-built CCS GCA workup includes baseline CXR, fasting glucose/HbA1c, DEXA scan, lipid panel, and PPD/IGRA—all reasonable before sustained immunosuppression. Don't forget eye exam by ophthalmology as part of baseline and surveillance.

Special Populations — Elderly and Renal/Hepatic Impairment

— Heightened steroid toxicity: osteoporotic fractures, hyperglycemia, hypertension, cataracts/glaucoma, skin fragility, infection, delirium, mood changes, weight gain, myopathy (paradoxical!).

— Falls risk: steroid myopathy + age-related sarcopenia → proactive PT referral, fall-risk assessment, home safety evaluation.

— Polypharmacy: review and minimize Beers Criteria medications; watch for steroid–NSAID GI bleed risk, steroid–warfarin INR fluctuations.

— Cognitive screening: rule out reversible causes of fatigue and depression before attributing to PMR alone.

— Baseline DEXA; repeat at 1–2 years on steroids.

— Calcium 1000–1200 mg + vitamin D 800–1000 IU daily.

— Oral bisphosphonate (alendronate, risedronate) for most patients with prednisone ≥7.5 mg/day ≥3 months expected, or moderate-to-high FRAX risk.

— Denosumab or zoledronate alternatives if oral intolerance.

— Prednisone is metabolized hepatically; no dose adjustment for renal impairment.

— Bisphosphonates contraindicated if CrCl <30–35 mL/min—use denosumab.

— Caution with NSAIDs in this population (often already poorly tolerated).

— Prednisone requires hepatic activation to prednisolone; in severe hepatic dysfunction, use prednisolone directly.

— Monitor LFTs; mild ALP elevation from disease itself usually improves with steroids.

— Methotrexate contraindicated in significant hepatic disease.

— Increased infection risk, but trial data support efficacy. Aggressive monitoring for bacterial infections, diverticulitis/perforation, hepatotoxicity.

Elderly considerations (most PMR/GCA patients are >70):

Bone health (priority intervention):

Renal impairment:

Hepatic impairment:

Tocilizumab in elderly:

Step 3 management: In an 80-year-old PMR patient with osteopenia and recent fall, initiate prednisone, bisphosphonate, calcium/vitamin D, PT referral, and home safety evaluation at the same visit—the steroid is necessary but predictably accelerates fall and fracture risk if you don't bundle prevention.

Special Populations — Pregnancy and Pediatrics

— PMR and GCA essentially do not occur in patients <50—the age threshold is part of diagnostic criteria.

— A child or young adult with "PMR-like" symptoms warrants evaluation for juvenile idiopathic arthritis, fibromyalgia, hypothyroidism, viral myositis, dermatomyositis, or Takayasu arteritis.

— Takayasu arteritis is the large-vessel vasculitis of the young (typically women <40)—shares granulomatous histology with GCA but affects aorta and primary branches without cranial features. Different population, different management duration, but similar treatment principles (high-dose steroids ± steroid-sparing agents).

— GCA and PMR are diseases of the elderly; pregnancy is not a realistic intersection.

— In the rare younger patient (or a relapse of PMR in someone unusually young who then conceives): prednisone is the steroid of choice in pregnancy due to placental metabolism by 11-β-HSD2 limiting fetal exposure. Methotrexate is teratogenic and contraindicated. Tocilizumab data in pregnancy are limited—generally avoided.

— Female predominance 2–3:1 in both PMR and GCA.

— Higher incidence in Scandinavian/Northern European populations; lower in African, Asian, and Hispanic populations.

— Don't anchor on ethnicity—still consider GCA in any patient >50 with appropriate symptoms.

— Steroid initiation will worsen control; coordinate with diabetes care—often need insulin temporarily, even in well-controlled type 2 patients. Strongly consider early tocilizumab to limit steroid exposure.

Pediatric considerations:

Pregnancy:

Sex and ethnic differences:

Patients with diabetes:

Board pearl: Suspected "GCA-like" symptoms in a young Asian woman with arm claudication, unequal BPs, and bruits = Takayasu arteritis, not GCA. Key distinction: age <40 + large-vessel disease + no cranial symptoms → Takayasu; age >50 + cranial symptoms + temporal artery abnormality → GCA.

Complications and Adverse Outcomes

— Permanent monocular or binocular vision loss from anterior ischemic optic neuropathy—the most feared complication; affects 15–20% of untreated GCA, often irreversible.

— Stroke, particularly vertebrobasilar territory (vertebral artery involvement), in 3–7%.

— Tongue or scalp necrosis (rare but classic).

— Thoracic aortic aneurysm/dissection—17× baseline risk; can present years after disease onset.

— Aortic regurgitation from aortic root dilation.

— Peripheral arm/leg claudication, subclavian steal.

— Generally low morbidity from the disease itself; functional disability from prolonged untreated stiffness.

— Increased risk of subsequent GCA in 15–20%—any new headache, jaw symptom, or visual change in a PMR patient should prompt urgent GCA workup.

— Osteoporotic fractures (vertebral compression, hip).

— Hyperglycemia and steroid-induced diabetes.

— Hypertension, weight gain, central adiposity, Cushingoid features.

— Cataracts, glaucoma.

— Skin atrophy, easy bruising, poor wound healing.

— Infections (bacterial, opportunistic—PJP, reactivation TB, herpes zoster).

— Adrenal suppression with abrupt discontinuation → adrenal crisis.

— Mood disorders, insomnia, psychosis (especially at initiation).

— Avascular necrosis of femoral head.

— Proximal myopathy (paradoxical—worsens stiffness, mimics relapse).

— Serious infections, GI perforation (especially with diverticular disease), neutropenia, transaminitis, dyslipidemia.

GCA-specific complications:

PMR-specific issues:

Steroid-related complications (often the dominant long-term morbidity):

Tocilizumab complications:

CCS pearl: A PMR patient on chronic prednisone who returns with new fatigue, hypotension, and hyponatremia after dose reduction → think adrenal insufficiency. Don't taper steroids below physiologic doses (5 mg) too quickly; consider AM cortisol or ACTH stim before complete discontinuation.

When to Escalate — ICU, Consult, and Inpatient Triage

— Uncomplicated PMR.

— GCA without visual or neurologic symptoms in a reliable patient who can start same-day oral prednisone and access urgent biopsy and ophthalmology.

— GCA with vision loss, amaurosis fugax, or diplopia → admit for IV pulse methylprednisolone × 3 days, urgent ophthalmology, and same-admission TAB scheduling.

— Stroke or TIA in suspected GCA.

— Severe systemic illness, profound constitutional symptoms, dehydration, or inability to tolerate oral therapy.

— Acute aortic syndrome (dissection, rupture).

— Aortic dissection or rupture from large-vessel GCA.

— Acute stroke requiring neuro-ICU level monitoring.

— Septic complications of immunosuppression.

— Rheumatology: ideally all GCA patients, complex PMR, and any patient needing steroid-sparing therapy. Step 3 favors timely outpatient referral within 1–2 weeks.

— Ophthalmology: urgent (same-day) for any visual symptom in suspected GCA; baseline eye exam in confirmed GCA; periodic monitoring for steroid-induced cataracts/glaucoma.

— Vascular or general surgery: for temporal artery biopsy.

— Cardiology/cardiothoracic surgery: for aortic aneurysm surveillance and management.

— Endocrinology: for refractory steroid-induced diabetes or adrenal insufficiency concerns.

Outpatient management is appropriate for:

Hospital admission considered for:

ICU considerations:

Specialist consultations:

Step 3 management: Vision loss in suspected GCA is a "do not pass go" emergency—the patient should be in the ED, on IV methylprednisolone, with ophthalmology at the bedside within hours. Even a single episode of amaurosis fugax in an elderly patient with elevated ESR triggers this pathway.

Board pearl: Don't admit uncomplicated PMR or GCA without visual/neurologic features—it's a Step 3 cost-and-value flag. Manage as outpatient with rapid follow-up (1–2 weeks initially, then per response).

Key Differentials — Other Inflammatory and Rheumatologic Causes

— Can mimic PMR with proximal stiffness in elderly.

— Distinguishing features: persistent peripheral synovitis (MCPs, wrists), positive RF or anti-CCP, erosive changes on hand films.

— May overlap—reconsider PMR diagnosis if peripheral synovitis persists despite steroid response.

— Elderly males with acute symmetric synovitis and dramatic pitting edema of hands/feet.

— Responds dramatically to low-dose steroids (like PMR).

— Can occur with PMR or as paraneoplastic—screen for occult malignancy.

— Proximal weakness (not pain), elevated CK, abnormal EMG, characteristic muscle biopsy and skin findings (Gottron papules, heliotrope rash in dermatomyositis).

— Key distinction: PMR = pain limits movement, strength preserved, CK normal. Inflammatory myopathy = weakness with normal strength testing impossible, CK elevated.

— Takayasu arteritis: large-vessel granulomatous, but in patients <40, no cranial features.

— ANCA-associated vasculitis (GPA, MPA, EGPA): pulmonary-renal syndrome, sinusitis, purpura, mononeuritis multiplex—different exam.

— Polyarteritis nodosa: medium-vessel, renal/GI/skin involvement, no temporal artery involvement.

— Polyarticular gout or pseudogout (CPPD) can mimic PMR with proximal pain, especially in elderly. Joint aspiration and crystal analysis distinguishes.

— Axial stiffness can resemble PMR neck/shoulder symptoms; check sacroiliac involvement, HLA-B27, peripheral enthesitis.

Late-onset rheumatoid arthritis (LORA):

RS3PE (Remitting Seronegative Symmetrical Synovitis with Pitting Edema):

Polymyositis/dermatomyositis:

Other vasculitides:

Crystal arthropathies:

Spondyloarthritis (late-onset):

Board pearl: Failure to respond to 15–20 mg prednisone within 1 week is a red flag against PMR. Order CK, RF, anti-CCP, SPEP, hand films, and re-examine for synovitis. The "PMR diagnosis" that doesn't respond often becomes LORA, malignancy, or inflammatory myopathy.

Key Differentials — Non-Rheumatologic Mimics

— Fatigue, proximal stiffness, myalgia, elevated CK, elevated ESR mildly.

— Always check TSH before committing to PMR. Replacement resolves symptoms.

— Proximal myalgia ± weakness, elevated CK, temporally related to statin initiation or dose change.

— Anti-HMGCR antibodies in rare necrotizing autoimmune myopathy (can persist after statin discontinuation).

— Trial statin discontinuation before locking in PMR diagnosis if symptoms are atypical or CK elevated.

— Multiple myeloma: elderly with bone pain, anemia, elevated ESR (often >100), renal dysfunction—order SPEP/UPEP and free light chains.

— Lymphoma, solid tumors: can present with constitutional symptoms, elevated ESR, and "PMR-like" pain.

— Poor steroid response or atypical features warrant CT chest/abdomen/pelvis and age-appropriate cancer screening.

— Endocarditis in elderly: fever, fatigue, elevated ESR, possible embolic phenomena—obtain blood cultures, echocardiogram.

— Osteomyelitis (vertebral): localized back pain, fever, elevated CRP—MRI.

— TB, HIV: chronic constitutional illness mimics.

— Mechanical neck/shoulder pain, unilateral or asymmetric, no systemic features, normal ESR/CRP. Examine for impingement signs.

— Widespread pain with tender points, normal ESR/CRP, no morning stiffness >45 min, and no response to low-dose prednisone.

— Rigidity and difficulty rising mistaken for PMR; look for tremor, bradykinesia, micrographia, normal inflammatory markers.

Hypothyroidism:

Statin-induced myopathy:

Malignancy (paraneoplastic syndromes):

Infections:

Cervical spondylosis or rotator cuff disease:

Fibromyalgia:

Parkinson's disease:

Key distinction: Normal ESR and CRP in a patient with proximal stiffness should redirect you toward fibromyalgia, hypothyroidism, OA, cervical spondylosis, or statin myopathy—not PMR. PMR with normal markers is possible but uncommon (<5%) and a high-stakes diagnostic move.

Long-Term Plan, Discharge, and Secondary Prevention

— PMR: typical duration 1–2 years, with slow taper. Up to 50% require some steroid for >2 years; relapses common during taper, especially below 7.5 mg.

— GCA: typical duration 2–3 years; relapses in 30–50%, usually managed with brief dose increases. Some require chronic low-dose maintenance.

— Calcium 1000–1200 mg/day (diet preferred) + vitamin D 800–1000 IU/day.

— Bisphosphonate for patients on prednisone ≥7.5 mg/day for ≥3 months, or moderate-to-high FRAX risk per ACR 2017 GIOP guidelines.

— Baseline and repeat DEXA at 1–2 years.

— Address BP, lipids, glucose aggressively—steroids amplify each.

— Low-dose aspirin in GCA per clinician judgment.

— Smoking cessation—significant GCA risk factor.

— Baseline aortic imaging (CTA or MRA) and periodic surveillance (e.g., every 2–3 years) recommended by EULAR; specifics evolving in US guidelines.

— Annual screening for aortic regurgitation by exam.

— Annual influenza, COVID-19 boosters, pneumococcal series, shingles (Shingrix)—prioritize before/during stable steroid period; avoid live vaccines on prednisone >20 mg/day or tocilizumab.

— Never abruptly stop steroids—adrenal crisis risk.

— Stress-dose steroids for major illness, surgery, trauma when on ≥5 mg/day prednisone >3 weeks.

— Medical alert ID for steroid dependence.

— Vision symptoms or new headache → call immediately—relapse with eye involvement is the dreaded outcome.

Long-term steroid plan:

Bone protection (mandatory):

Cardiovascular risk reduction:

Aortic surveillance in GCA:

Vaccinations:

Patient education and counseling:

Step 3 management: Build the discharge bundle around: steroid taper schedule, bone protection, vaccinations, BP/glucose/lipid optimization, aspirin decision, rheumatology follow-up in 2–4 weeks, and explicit patient instruction on relapse symptoms and stress-dose steroids.

Follow-Up, Monitoring, and Counseling

— First visit 1–2 weeks after diagnosis: confirm clinical response, recheck ESR/CRP, screen for steroid side effects (glucose, BP).

— Every 2–4 weeks during active taper; every 3 months once stable on low maintenance dose; every 6 months in remission.

— Lifelong vigilance—late GCA relapses and aneurysm complications occur years later.

— Symptom recurrence: stiffness, headache, jaw or visual symptoms, claudication.

— Steroid side effects: weight, BP, fasting glucose/HbA1c, mood, sleep, skin, bruising, fracture history.

— Functional status: ability to perform ADLs, fall history.

— Adherence and taper schedule comprehension.

— ESR and CRP at every visit during active disease; sustained elevation despite clinical remission may prompt imaging for large-vessel disease (caveat: tocilizumab suppresses CRP).

— CBC (anemia, neutropenia on tocilizumab/methotrexate), CMP (glucose, LFTs), lipids, HbA1c.

— Baseline and surveillance CTA or MRA of aorta in GCA per shared-decision rheumatology plan.

— DEXA at baseline and 1–2 year intervals.

— Exercise: light-to-moderate aerobic and resistance training maintains muscle mass against steroid myopathy and bone loss.

— Diet: lower-glycemic, sodium-conscious, calcium-rich.

— Mental health: monitor for steroid-induced mood disorders; many patients benefit from sleep hygiene counseling.

— Driving and vision: re-evaluate fitness to drive in GCA-related vision loss.

Follow-up cadence:

At each visit, assess:

Laboratory monitoring:

Imaging monitoring:

Counseling:

CCS pearl: Build "advance to next location" decisions around: symptoms improved, ESR/CRP trending down, no new visual or jaw symptoms, glucose and BP controlled, bone protection initiated, rheumatology arranged. Missing DEXA, bisphosphonate, or vaccination updates is a common CCS deduction in long-term care of steroid-dependent patients.

Ethical, Legal, and Patient Safety Considerations

— Counsel patients about substantial risks of prolonged glucocorticoids (osteoporosis, diabetes, infection, cataracts, weight gain, mood changes) before initiating, even when treating empirically for GCA. Document discussion.

— Discuss that treating empirically is standard of care because delay risks irreversible blindness.

— Steroid taper schedules are a common handoff error—medication reconciliation at every transition (ED → floor → discharge → primary care → rheumatology). Provide written taper schedule to patient and PCP.

— Explicit instructions on what to do for missed doses, stress-dose steroids for illness/surgery, and adrenal crisis symptoms.

— Patients on chronic steroids should carry medical alert identification stating steroid dependence.

— Document stress-dose steroid plan for elective surgery, dental procedures, and intercurrent illness.

— GCA-related monocular or binocular vision loss may trigger state-mandated reporting requirements for driving fitness (varies by state). Counsel patient and family; coordinate with ophthalmology.

— Live vaccines contraindicated on prednisone ≥20 mg/day for >2 weeks and on tocilizumab. Patient safety event if administered inappropriately—verify and document at every immunosuppression change.

— Many patients are elderly with comorbidities; align long-term steroid burden with patient goals of care. Discuss tocilizumab as a steroid-sparing option for those with severe diabetes, osteoporosis, or psychiatric history.

— Tocilizumab is expensive—verify insurance coverage and explore patient assistance programs. Document medical necessity carefully.

Informed consent for empiric steroids:

Transition-of-care safety:

Medical alert and emergency planning:

Vision loss and driving:

Vaccine and immunosuppression safety:

Elder autonomy and shared decision-making:

Cost considerations:

Step 3 management: Document a clear, written, dated taper plan in the chart and hand a copy to the patient. Failure to communicate steroid taper at transitions is a leading source of iatrogenic adrenal insufficiency—a tested patient safety event.

High-Yield Associations and Rapid-Fire Facts

— Age ≥50, peak 70s–80s. Female:male ~2–3:1. Northern European descent. Strong HLA-DR4 association.

— Elevated ESR (often >50), elevated CRP, normocytic anemia + thrombocytosis.

— New headache + jaw claudication + elevated ESR in >50 = GCA until proven otherwise.

— Bilateral shoulder/hip stiffness + morning stiffness >45 min + elevated ESR in >50 = PMR.

— PMR: prednisone 15–20 mg/day.

— GCA, no vision threat: 40–60 mg/day.

— GCA, vision threat: IV methylprednisolone 1 g/day × 3 → oral.

— Tocilizumab is FDA-approved for GCA; methotrexate has modest benefit. Tocilizumab suppresses CRP independent of disease.

— Long segment (≥1–2 cm), skip lesions, granulomas with multinucleated giant cells, fragmented internal elastic lamina, intimal hyperplasia. Stays positive 2–4 weeks after steroid initiation.

— Ultrasound "halo sign" = hypoechoic wall thickening.

— CTA/PET-CT for large-vessel disease.

— Irreversible monocular vision loss (anterior ischemic optic neuropathy).

— Thoracic aortic aneurysm (17× risk).

— Vertebrobasilar stroke.

— Hypothyroidism, statin myopathy, multiple myeloma, late-onset RA, polymyositis, endocarditis, RS3PE, fibromyalgia, Takayasu (in young).

— Bone protection from day 1, vaccinations updated, glucose/BP monitoring, taper plan written, stress-dose education.

PMR/GCA epidemiology:

Lab triad to remember:

Symptom triggers:

Dose recall:

Steroid-sparing:

Biopsy facts:

Imaging facts:

Complications:

Mimics to exclude:

Steroid-related must-dos:

Board pearl: The single highest-yield Step 3 reflex for this topic: elderly patient + new headache or visual symptom + elevated ESR → start high-dose steroids immediately, then arrange biopsy. Memorize the doses—they appear on virtually every USMLE iteration of this topic.

Board Question Stem Patterns

— "A 72-year-old woman presents with a 2-week history of new throbbing right temporal headache, scalp tenderness when combing her hair, and jaw fatigue with chewing. ESR is 88, CRP 6.2. Funduscopy is unremarkable. Next best step?"

— Answer: Start high-dose prednisone (60 mg PO) immediately, then arrange temporal artery biopsy within 1–2 weeks. Do not delay steroids for biopsy.

— Sudden monocular vision loss with pale swollen disc and flame hemorrhages in elderly with elevated ESR.

— Answer: IV methylprednisolone 1 g/day × 3 days, urgent ophthalmology, then oral prednisone 60 mg/day. Biopsy within 2 weeks.

— "A 68-year-old man with 6 weeks of bilateral shoulder and hip girdle stiffness, worst in the morning lasting 90 minutes, difficulty rising from a chair. ESR 64, CRP 4.1, CK normal, RF negative."

— Answer: Prednisone 15–20 mg PO daily; expect dramatic response within 1 week. Plan bone protection.

— Same presentation but no response to 20 mg prednisone after 10 days → reconsider diagnosis: check anti-CCP, SPEP, repeat exam for synovitis, screen for malignancy.

— PMR patient on chronic 10 mg prednisone with new vertebral compression fracture → answer involves bone protection failure; intensify with bisphosphonate, calcium, vitamin D, DEXA.

— Patient on chronic steroids stops abruptly before surgery → hypotension, nausea, hyponatremia.

— Answer: stress-dose hydrocortisone, IV fluids, and avoid abrupt discontinuation.

— GCA patient on tocilizumab with new abdominal pain → consider GI perforation/diverticulitis.

— GCA patient years later with chest pain and widened mediastinum → thoracic aortic dissection.

Classic GCA stem:

GCA with vision loss stem:

PMR classic stem:

PMR mimicker stem:

Steroid complication stem:

Adrenal insufficiency stem:

Tocilizumab stem:

Aortic aneurysm stem:

Board pearl: Pattern recognition is the entire game—three numbers to memorize: prednisone 15–20 (PMR), 40–60 (GCA), 1000 mg IV × 3 (GCA + vision loss). Recognize the trigger symptom, pick the dose, add bone protection, and arrange biopsy.

One-Line Recap

In any patient ≥50 with new bilateral proximal stiffness (PMR) or new headache, jaw claudication, or visual symptoms with elevated ESR/CRP (GCA), start glucocorticoids immediately—15–20 mg prednisone for PMR and 40–60 mg (or pulse IV methylprednisolone if vision is threatened) for GCA—then arrange temporal artery biopsy within 1–2 weeks and bundle bone protection, vaccination, and long-term monitoring from day one.

Diagnose by pattern: Age ≥50 + proximal stiffness + elevated ESR/CRP = PMR; add headache, jaw claudication, scalp tenderness, or visual symptoms = GCA. Both share elevated inflammatory markers, thrombocytosis, and dramatic steroid responsiveness.

Treat before you prove: Empiric high-dose steroids in suspected GCA—even before biopsy—because vision loss is irreversible and bilateral within days. Biopsy stays positive 2–4 weeks after steroid initiation; never delay therapy for it.

Anticipate steroid harm: Bone protection (calcium, vitamin D, bisphosphonate), glucose and BP monitoring, vaccination updates (Shingrix, pneumococcal, influenza), and a written taper schedule are non-negotiable from day one; tocilizumab is the steroid-sparing agent of choice in relapse or steroid intolerance for GCA.

Watch for long-tail complications: Thoracic aortic aneurysm (17× risk in GCA), vertebrobasilar stroke, late relapses, and steroid-induced osteoporosis or adrenal insufficiency drive lifelong follow-up—rheumatology partnership, aortic imaging surveillance, and patient education on stress-dose steroids and warning symptoms are the cornerstones of high-quality longitudinal care on Step 3.