Ecthyma is a bacterial skin infection caused by streptococcal or staphylococcal organisms.
Streptococcal and staphylococcal bacteria may cause skin infections at various levels and depths. Ecthyma is similar to impetigo, but causes deeper erosions of the skin. The infection may start at the site of a bug bite or scratch.
The streptococcal organism most often causes ecthyma. Any trauma or break in the skin allows the bacteria to begin growing.