Chronic undermining burrowing ulcer

A chronic undermining burrowing ulcer is a bacterial gangrene that occurs after surgery. It's a progressive condition that can rapidly spread to a large area. It's most often seen in people who are immunocompromised , especially after abdominal surgery.

An undermining ulcer is a wound where the damage under the tissue is larger than what appears at the surface. The tissue under the epidermis erodes away from the edges of the initial wound, creating a pocket of dead space under the surface.

Chronic ulcers can become deep and extend to the bone, allowing bacteria to infect the bone. Once this is established, the ulcer will not heal unless the bone infection is treated.

Ulcers that heal within 12 weeks are usually classified as acute, and longer-lasting ones as chronic.