Gangrenous staphylococcal infections localized on the lesions of acquired reactive perforating collagenosis

We report a 78-year-old man with diabetic nephropathy, who presented with acquired reactive perforating collagenosis, followed by gangrenous infections localized on the lesions. Histopathological findings revealed a feature of transepidermal elimination of degenerated collagen bundles associated with infiltrates of neutrophils. Staphylococcus aureus was isolated from the necrotic tissue. The infection was successfully treated with systemic antibiotics and debridement. We believe that the presence of necrotic plug in the lesions and microangiopathy due to diabetes mellitus may provide a susceptible milieu for bacterial inoculation.