Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
2 min synopsisUK scopeSources checked 27 Aug 2026Clinical review pending
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Acute CPP arthritis can mimic sepsis
A hot swollen knee or wrist with fever and very high inflammatory markers may be calcium-pyrophosphate arthritis, septic arthritis or both; crowned dens syndrome can also resemble meningitis or giant cell arteritis.
Action: Use the urgent hot-joint or acute-neck-pain pathway, aspirate and culture before antibiotics when safe, obtain blood cultures in systemic illness, provide sepsis treatment without delay and avoid intra-articular corticosteroid until infection is reasonably excluded.
Synopsis
Recognise acute, chronic and asymptomatic calcium-pyrophosphate phenotypes, confirm crystals while excluding infection, identify important metabolic associations and treat inflammation without promising a crystal-dissolving therapy.
CPPD is an umbrella for asymptomatic chondrocalcinosis, acute CPP crystal arthritis, chronic CPP inflammatory arthritis and osteoarthritis with CPP deposits; avoid the imprecise term pseudogout when a phenotype can be named.
Acute CPP arthritis commonly affects an older adult's knee or wrist, can be intensely painful and febrile and may take longer than gout to settle.
The reference confirmation is CPP crystals in symptomatic-joint fluid: usually rhomboid or rod-shaped and weakly positively birefringent under compensated polarised light.
Key red flags
Fever, shock, prosthesis, recent joint procedure, skin breach or bacteraemia requires immediate septic-arthritis assessment regardless of chondrocalcinosis.
Crowned dens syndrome
Acute upper-neck pain, restricted rotation, fever and high inflammatory markers with peri-odontoid CT calcification defines this CPPD presentation.
Confirm CPP crystals in a symptomatic joint and distinguish gout.
Management branches
First diagnostic priorityAspirate the hot joint
An acute effusion with severe warmth and restricted movement is present.
Check sepsis, prosthesis, recent procedure, skin breach and bacteraemia and obtain observations and blood cultures when systemically unwell.
Aspirate before antibiotics when safe, sending cell count, Gram stain, culture and expert polarised microscopy for CPP and urate crystals.
Preferred local treatmentAspirate then inject
One accessible joint is affected and infection has been reasonably excluded.
Key medicines
Intra-articular triamcinolone acetonideAfter aspiration and infection exclusion, inject 5 to 10 mg into a small joint or up to 40 mg into a large joint using the 40 mg/mL suspension and strict asepsis; dose depends on joint size and inflammation.
Colchicine for acute CPP arthritisA common specialist off-label regimen is 500 micrograms orally twice daily for 3 to 5 days, reduced to once daily in selected older or renally impaired patients and stopped promptly when symptoms settle or toxicity occurs.
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.