Summary
Pseudoepitheliomatous hyperplasia of the epidermis occurring with Mycobacterium ulcerans skin infection may result in localization of the infected area with discharge of necrotic material, followed by healing leaving a depressed scar. The process represents more than simple re-epithelization of an ulcerated skin surface; it is a mechanism which produces active extrusion of necrotic material containing viable mycobacteria and should be seen as part of a protective physiological response to the infection.