Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Impetigo ?
    ### Response:
    Impetigo is a skin infection caused by bacteria. It is usually caused by staphylococcal (staph) bacteria, but it can also be caused by streptococcal (strep) bacteria. It is most common in children between the ages of two and six. It usually starts when bacteria get into a break in the skin, such as a cut, scratch, or insect bite.
    