What is impetigo caused by?

Impetigo is a common skin infection that is caused by bacteria, specifically the bacteria Streptococcus pyogenes (group A streptococcus) or Staphylococcus aureus. These bacteria can enter the skin through breaks in the skin, such as cuts, scrapes, or insect bites, and cause an infection. Impetigo is characterized by red, weeping, crusty sores on the skin that can be itchy and painful. It is highly contagious and can be spread through direct contact with an infected person or through contact with contaminated objects.