Musculoskeletal for PLAB 1

A 54 year old man has severe pain and swelling of the right first metatarsophalangeal joint that developed over six hours overnight. The joint is red, hot and exquisitely tender, and he cannot bear the weight of a bedsheet on it. He is afebrile and systemically well. He takes bendroflumethiazide and drinks eight pints of beer at weekends. His serum urate today is 340 µmol/L. What is the SINGLE most likely diagnosis?

1. Osteoarthritis Gradual pain worse on use with bony swelling, and an acute flare can be mistaken for crystal disease. A normal urate during an acute first metatarsophalangeal attack makes it plausible.
2. Crystal arthropathy Acute monoarthritis with crystals in the joint fluid, either urate or calcium pyrophosphate. A normal urate during an acute first metatarsophalangeal attack fits.
3. Gout correct Correct. A rapidly developing exquisitely painful monoarthritis of the first metatarsophalangeal joint, in a man on a thiazide who drinks beer. The clinical picture is close to diagnostic.
4. Pseudogout Acute knee or wrist arthritis in an older patient, with chondrocalcinosis and positively birefringent rhomboid crystals. A normal urate during an acute first metatarsophalangeal attack points to it.
5. Septic arthritis A hot swollen joint with fever and systemic upset, and it must be excluded before anything is called gout. A normal urate during an acute first metatarsophalangeal attack demands exclusion.

The point: Gout is a rapidly developing severe monoarthritis, most often the first metatarsophalangeal joint, and a serum urate taken during an attack can be normal, so a normal urate does not exclude it. Measure urate at least two weeks after the attack has settled. Joint aspiration shows negatively birefringent needle-shaped crystals, and it is essential wherever septic arthritis is possible. Treat the attack with an NSAID, colchicine or a steroid, choosing by comorbidity: NSAIDs are avoided in renal impairment, heart failure and peptic ulceration, and colchicine is dose-limited by diarrhoea. Start allopurinol after the attack or during it with cover, and continue it through subsequent attacks rather than stopping. Target a urate below 360 µmol/L, or below 300 with tophi or frequent attacks. Pseudogout gives positively birefringent rhomboid crystals with chondrocalcinosis on the radiograph.

Source: NICE NG219 — Gout: diagnosis and management NICE · tier 1, national regulator or guidance

A 54 year old man has severe pain and swelling of the right first metatarsophalangeal joint that developed over six hours overnight. The joint is red, hot and exquisitely tender, and he cannot bear the weight of a bedsheet on it. He is afebrile and systemically well. He takes bendroflumethiazide and drinks eight pints of beer at weekends. His serum urate today is 340 µmol/L. What is the SINGLE most appropriate initial investigation?

1. Plain radiograph of the joint Chondrocalcinosis in pseudogout, and punched-out erosions with overhanging edges in chronic tophaceous gout. A normal urate during an acute first metatarsophalangeal attack makes it useful.
2. Renal function and review the drug chart Diuretics raise urate and renal impairment restricts which drugs can be used for the attack. A normal urate during an acute first metatarsophalangeal attack makes it central.
3. Serum urate at least two weeks after the attack correct Correct. His level of 340 today means nothing, because urate falls during an attack. Repeating it in two weeks gives a usable baseline and a target.
4. Blood glucose and lipids Gout clusters with obesity, hypertension, diabetes and cardiovascular disease, and the attack is an opportunity. A normal urate during an acute first metatarsophalangeal attack makes it worthwhile.
5. Calcium, magnesium, ferritin and thyroid function For pseudogout in a younger patient, looking for haemochromatosis, hyperparathyroidism or hypothyroidism. A normal urate during an acute first metatarsophalangeal attack indicates it.

The point: Gout is a rapidly developing severe monoarthritis, most often the first metatarsophalangeal joint, and a serum urate taken during an attack can be normal, so a normal urate does not exclude it. Measure urate at least two weeks after the attack has settled. Joint aspiration shows negatively birefringent needle-shaped crystals, and it is essential wherever septic arthritis is possible. Treat the attack with an NSAID, colchicine or a steroid, choosing by comorbidity: NSAIDs are avoided in renal impairment, heart failure and peptic ulceration, and colchicine is dose-limited by diarrhoea. Start allopurinol after the attack or during it with cover, and continue it through subsequent attacks rather than stopping. Target a urate below 360 µmol/L, or below 300 with tophi or frequent attacks. Pseudogout gives positively birefringent rhomboid crystals with chondrocalcinosis on the radiograph.

Source: NICE NG219 — Gout: diagnosis and management NICE · tier 1, national regulator or guidance

A 54 year old man has severe pain and swelling of the right first metatarsophalangeal joint that developed over six hours overnight. The joint is red, hot and exquisitely tender, and he cannot bear the weight of a bedsheet on it. He is afebrile and systemically well. He takes bendroflumethiazide and drinks eight pints of beer at weekends. His serum urate today is 340 µmol/L. What is the SINGLE most appropriate immediate management?

1. Naproxen with gastric protection correct Correct. First line for an acute attack where renal function is normal and there is no contraindication. Colchicine or a steroid would be the alternatives.
2. Lifestyle advice on alcohol, purines and weight Modest effect compared with allopurinol, and worth giving alongside rather than instead. A normal urate during an acute first metatarsophalangeal attack makes it complementary.
3. Rest, ice and analgesia Supportive measures alongside drug treatment for any acute crystal attack. A normal urate during an acute first metatarsophalangeal attack makes it supportive.
4. Start allopurinol once the attack has settled Titrated to a urate below 360, with colchicine cover for the first few months because mobilising crystals provokes flares, and a normal urate during an acute first metatarsophalangeal attack here points elsewhere.
5. Oral or intra-articular corticosteroid Where both an NSAID and colchicine are unsuitable, and only once infection has been excluded. A normal urate during an acute first metatarsophalangeal attack meets that.

The point: Gout is a rapidly developing severe monoarthritis, most often the first metatarsophalangeal joint, and a serum urate taken during an attack can be normal, so a normal urate does not exclude it. Measure urate at least two weeks after the attack has settled. Joint aspiration shows negatively birefringent needle-shaped crystals, and it is essential wherever septic arthritis is possible. Treat the attack with an NSAID, colchicine or a steroid, choosing by comorbidity: NSAIDs are avoided in renal impairment, heart failure and peptic ulceration, and colchicine is dose-limited by diarrhoea. Start allopurinol after the attack or during it with cover, and continue it through subsequent attacks rather than stopping. Target a urate below 360 µmol/L, or below 300 with tophi or frequent attacks. Pseudogout gives positively birefringent rhomboid crystals with chondrocalcinosis on the radiograph.

Source: NICE NG219 — Gout: diagnosis and management NICE · tier 1, national regulator or guidance