skip to main content

Pyoderma Gangrenosum — SCE Infectious Diseases MCQ

Instant feedback + full explanation. One question, done properly.

ModerateInfection Prevention & ControlPyoderma GangrenosumSCE Infectious Diseases

A 32-year-old woman from West Africa presents with a chronic ulcer on her shin showing undermined violaceous borders. She has been treated with multiple courses of antibiotics without improvement. Biopsy shows neutrophilic dermatosis with no organisms. She has IBD diagnosed 2 years ago. What is the most likely diagnosis?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: E — Pyoderma gangrenosum (non-infectious)

A chronic non-healing ulcer with violaceous undermined borders, neutrophilic dermatosis on biopsy, negative cultures, failure to respond to antibiotics, and association with IBD is classic for pyoderma gangrenosum (PG). This is a non-infectious neutrophilic dermatosis, not an infection. Treatment is immunosuppression (topical Tacrolimus, systemic steroids, or biologics). Debridement is contraindicated as it worsens PG (pathergy). The travel history is a distractor — the clinical features and IBD association point to PG.

Reference: BAD 2023 – Pyoderma gangrenosum; NICE CKS 2024 – PG