PLAB 1 Musculoskeletal Medicine & Rheumatology 3

Question 1

A 62-year-old man presents with acute knee pain and swelling. Joint aspiration reveals positively birefringent rhomboid-shaped crystals under polarised light microscopy. What is the diagnosis?

Accepted Answer

Pseudogout (calcium pyrophosphate deposition)

Answer

Gout

Answer

Septic arthritis

Answer

Haemarthrosis

Question 2

A patient with a known diagnosis of rheumatoid arthritis is to be started on an anti-TNF biologic agent. Which pre-treatment screening is MOST important before initiating therapy?

Accepted Answer

Tuberculosis screening (IGRA or Mantoux)

Answer

HIV serology

Answer

Hepatitis C antibody

Answer

MRSA nasal swab

Question 3

What is the mechanism of action of allopurinol in the management of gout?

Accepted Answer

Inhibits xanthine oxidase, reducing uric acid production

Answer

Increases renal excretion of uric acid via uricosuric effect

Answer

Promotes dissolution of urate crystals in joints

Answer

Blocks intestinal absorption of purines

Question 4

A 38-year-old woman with SLE and confirmed antiphospholipid syndrome has had two consecutive first-trimester miscarriages. What is the recommended management during her next pregnancy?

Accepted Answer

Low-dose aspirin plus low molecular weight heparin (LMWH)

Answer

High-dose prednisolone

Answer

Hydroxychloroquine alone

Answer

Warfarin throughout pregnancy

Question 5

A 65-year-old woman with a history of RA and chronic kidney disease develops a severe skin rash after starting allopurinol. What interaction must be warned about when prescribing allopurinol alongside azathioprine?

Accepted Answer

Allopurinol inhibits azathioprine metabolism, causing potentially fatal toxicity

Answer

Allopurinol reduces azathioprine efficacy

Answer

Azathioprine reduces allopurinol absorption

Answer

The combination causes severe hyperkalaemia

Question 6

Which DMARD requires regular monitoring of full blood count, liver function tests, and renal function every 2–3 months due to risks of hepatotoxicity and bone marrow suppression?

Accepted Answer

Methotrexate

Answer

Hydroxychloroquine

Answer

Sulfasalazine

Answer

Leflunomide

Question 7

A 30-year-old woman is newly diagnosed with SLE. Which medication is recommended as background therapy for virtually ALL SLE patients unless contraindicated, as it reduces flares and organ damage?

Accepted Answer

Hydroxychloroquine

Answer

Prednisolone

Answer

Azathioprine

Answer

Mycophenolate mofetil