IBD Skin Flares: Pyoderma Gangrenosum and Erythema Nodosum

Content note: Educational content aligned with publicly available patient materials from the Crohn's & Colitis Foundation and other major IBD education sources. IBDPal is not affiliated with or endorsed by the Foundation. Last reviewed June 2026. Not individual medical advice.

Educational use only. IBDPal does not provide medical advice, diagnosis, or treatment. Always consult your gastroenterologist or IBD care team for personal decisions.

Skin can flare with IBD even when stools feel quieter. Two names patients hear often are erythema nodosum (EN) and pyoderma gangrenosum (PG). Both need clinician judgment; neither is a do-it-yourself dermatology project.

Erythema nodosum in brief

EN often looks like tender red nodules on the shins. It may rise with gut activity and settle as inflammation is treated. Fever and joint aches can travel with it. Report new painful shin nodules promptly rather than waiting for a routine visit months away.

Pyoderma gangrenosum in brief

PG is rarer and more destructive. It can start as a pustule or bruise-like spot and enlarge into a painful ulcer. Trauma to the skin can worsen it. Do not pack aggressive debridement at home. Dermatology and GI usually co-manage.

Call same day or urgently if

• A skin lesion expands quickly or becomes deeply painful
• Fever with spreading redness
• A surgical or ostomy site looks infected or opens

Send a photo through your patient portal if the clinic accepts images.

Questions for your team

• Is this likely EN, PG, infection, or something else?
• Do we need dermatology this week?
• Should systemic IBD therapy change because of the skin?

Related: joint pain, eye inflammation, flare help.

Photos: Unsplash License (free use).

Medical Disclaimer

This article is for educational purposes only and should not replace professional medical advice, diagnosis, or treatment. Always consult your healthcare provider regarding dietary, medication, or lifestyle decisions.