Ecthyma

Definition:

A skin infection similar to impetigo but more deeply invasive than impetigo.

Causes, incidence, and risk factors:

Streptococcus is the most common infectious organism in an ecthyma. The infection may start at the site of an injury such as a scratch or insect bite and is often found on the legs. An ecthyma may begin with a pus-filled blister that develops into a shallow ulcer with raised borders. A hard crust may form over the ulcer.