30th July 2023

A 24-year-old man with a background of ulcerative colitis presents to his GP with new lesions on his left leg

A 24-year-old man with a background of ulcerative colitis presents to his GP with new lesions on his left leg. He denies any preceding trauma, insect bites or new medication. On inspection of the lower limbs, single erythematous papules with deep ulcerations are seen.

What is the likely explanation for this presentation?

Select the SINGLE most appropriate option from the list below. Select ONE option only.