Streptococcal skin infections are bacterial infections that affect the skin and underlying tissue. They are often caused by Group A streptococcal (strep) bacteria. When the strep bacteria get into open skin (such as from a cut, a scratch, or an insect bite), they can cause an infection. These can be mild infections on the surface of the skin. Or they can be deeper and more severe.
Strep bacteria can also cause other problems. These include strep throat, scarlet fever, streptococcal toxic shock syndrome (STSS), and rheumatic fever.