30th July 2023

A 27-year-old woman with a background of Crohn’s disease presents to A&E with painful erythematous plaques

A 27-year-old woman with a background of Crohn’s disease presents to A&E with painful erythematous plaques on her upper limbs and neck. She was also pyrexial, with blood tests revealing a raised CRP and ESR. The lesions were reviewed by the dermatology team, who recommended systemic glucocorticoids whilst they arranged a skin biopsy. The lesions showed an excellent clinical response to the steroids, and biopsy findings revealed dense neutrophilic infiltrate without evidence of leukocytoclastic vasculitis.

What is the likely explanation for the appearance?

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