19th January 2024

A 35-year-old male presents to A&E with left eye redness and watering, which developed over the past 24 hours.

A 35-year-old male presents to A&E with left eye redness and watering, which developed over the past 24 hours. He reports no past medical history, but mentions he has experienced pain in some of the joints of his right hand over the past few months. He denies any recent trauma or infections. On examination, he has swelling of the whole third and fourth fingers of the right hand, and you notice some scaly, erythematous plaques on his shins. Blood test results showed the following.

Hb 123 g/L (130-180)

MCV 94.5fL (80-96)

WCC 6.0 x 10⁹/L (4.0-11.0)

CRP 37 mg/L (<10)

Sodium 142 (133–146 mmol/L)

Potassium 4.6 (3.5–5.3 mmol/L)

Creatinine 77 (45–84 μmol/ L)

EGFR >90

ESR 4

LFTs normal

Rheumatoid factor 10 (0-20 u/mL)

What is the most likely diagnosis?