• Cause: deposition of monosodium urate crystals in joints (hyperuricaemia)
• Crystals:
o Needle-shaped
o Negatively birefringent under polarised light
• Typical presentation:
o Sudden onset monoarthritis (e.g. 1st MTP — podagra)
o Erythema, severe pain, swelling
• Risk factors:
o Male, obesity, alcohol, thiazides, CKD, high-purine diet
• Tests:
o Serum uric acid (can be normal in acute attack)
o Joint aspiration: diagnostic (rule out septic arthritis)
o U&E (check for CKD), consider urate crystals in tophi
• Management:
o Acute:
NSAIDs (first-line if no contraindications)
Colchicine (GI side effects common)
Steroids (oral or intra-articular)
o Chronic (urate lowering therapy):
Allopurinol (xanthine oxidase inhibitor) – start 2 weeks after flare settles
Febuxostat (if allopurinol not tolerated)
Aim for serum urate <360 µmol/L
Co-prescribe colchicine 500 mcg OD–BD for flare prophylaxis when initiating urate-lowering therapy
• Crystals:
o Rhomboid-shaped
o Positively birefringent
• Typical joints:
o Knee, wrist, shoulder
• Radiology:
o Chondrocalcinosis (calcification of cartilage) on X-ray
• Associated conditions:
o Haemochromatosis
o Hyperparathyroidism
o Hypomagnesaemia
o Hypothyroidism
• Management: similar to gout
o NSAIDs, colchicine, steroids
o No long-term urate-lowering therapy
• Features:
o Affects weight-bearing joints: knees, hips, spine
o Also affects DIPs, PIPs, 1st CMC (unlike RA)
o Morning stiffness <30 minutes, worsens with use
• Signs:
o Heberden’s nodes (DIP)
o Bouchard’s nodes (PIP)
o Joint crepitus, reduced range of motion
• X-ray findings:
o Joint space narrowing
o Subchondral sclerosis
o Osteophytes
o Subchondral cysts
• Management:
o Non-pharmacological: weight loss, exercise, physio
o Pharmacological: paracetamol ± topical NSAIDs → oral NSAIDs ± PPI → intra-articular steroids
o Consider surgery if severe (e.g. joint replacement)
• Includes hydroxyapatite deposition disease
• Not birefringent, not seen on standard microscopy
• Requires electron microscopy or special stains for identification
• Presentation:
o Often affects shoulder (“Milwaukee shoulder”)
o May cause destructive arthropathy, effusions
• Treatment: conservative, NSAIDs, physiotherapy; joint lavage in severe cases
————————————————————————————————————————————————————————————————————————————————————————————————————————-
Author & Educational Disclaimer
Author:
Dr Phillip Cockrell BM FRCP DipClinEd
Dr Phillip Cockrell is a UK Consultant Physician in Internal Medicine, currently working at Queen Alexandra Hospital, Portsmouth University Hospitals NHS Trust. He has previously worked as a registrar across Intensive Care Medicine, Gastroenterology, Cardiology, Stroke Medicine, Acute Medicine, and Respiratory Medicine.
He has held senior leadership roles including Associate Clinical Director of the Acute Medical Unit, Clinical Director of Internal Medicine, and Chief of Medicine. Dr Cockrell has over 15 years’ experience in postgraduate medical education, having lectured extensively across the MRCP syllabus and contributed to MRCP revision teaching and course development.
Dr Cockrell holds a Bachelor of Medicine (BM), Fellowship of the Royal College of Physicians (FRCP), and a Diploma in Clinical Education (DipClinEd). His teaching approach is based on structured consolidation of complex medical topics to support efficient and effective revision for postgraduate examinations.
Purpose of this content:
The material on this page is intended solely for educational purposes to support revision for the MRCP (UK) Part 1 examination. It reflects examination-relevant principles of internal medicine and is designed to aid learning and pattern recognition.
Medical disclaimer:
This content is designed for postgraduate medical examination revision and does not constitute medical advice, diagnosis, or treatment guidance and must not be used as a substitute for professional clinical judgement, local guidelines, or specialist consultation. Clinical decisions should always be made in the context of individual patient circumstances and current national guidance.
