Your skin is the largest organ in your body, and it's home to a variety of bacteria, including Staphylococcus and Streptococcus, which cause impetigo. While both types of bacteria normally live on your skin without harm, they can tunnel their way into a cut, scrape or rash and cause an infection [source: Mayo Clinic].
Impetigo is far more common in children than adults because children are more likely to have cuts and scrapes and to scratch mosquito bites and rashes. Children also spend a lot of time in crowded, germ-ridden places, such as schools, and children's fledgling immune systems can't always fight off bacteria. In adults, impetigo often develops during a bout with dermatitis, which is a routine -- but not contagious -- skin allergy.
Impetigo infections occur when bacteria appear in a cut or sore. The bacteria produce a toxin that attacks the binding proteins in skin cells, which are the proteins that help the cells stick together. When this occurs, the bacteria multiply, causing itchy rashes, unsightly sores and oozing, crusty blisters that can easily spread to other parts of the body [source: Mayo Clinic].
While you can't exactly grow a thicker skin to prevent impetigo, you can take some precautions to reduce the likelihood of infection. For example, you can keep an eye on cracked, cut or irritated skin and keep damaged areas clean and dry. You also can limit direct contact with someone who has impetigo and launder any linens or garments that might have been exposed to the infection. Read on for more tips on avoiding and treating impetigo.