Infantigo, or "Impetigo," as it's properly termed, occurs when either staphylococcus aureus (staph) or streptococcus pyogenes (strep) bacteria enter the bloodstream. The disease is commonly known as "infantigo" because it most often occurs in infants and young children, and is highly contagious in those age groups. Though both bacteria can cause impetigo, according to the Mayo Clinic staphylococcus aureus is by far the most common culprit when a patient has contracted the disease. Impetigo is treated with antibiotics and preventable through hygienic measures.
Injuries to Skin
Staph and strep germs can live on the skin without harming the individual; most adults who contract impetigo do so through a direct break in the skin such as a cut, which allows bacteria to enter the skin cells. In a similar manner, children typically contract the disease through a scrape, cut or insect bite. The government website Medicine Plus says that infection can also be caused by an animal or human bite that breaks the skin.
Rashes and Dermatitis
If a person has an ongoing rash or other type of dermatitis such as eczema, it may lead to impetigo through the open sores on the skin. Likewise, poison ivy or oak can allow the bacteria to penetrate the skin barrier, as can a diaper rash.
Impetigo may occur on otherwise healthy skin, where there is no noticeable injury. This is typically due to direct contact with an infected person and is why the disease is more prevalent in young children. The bacteria can also be spread through contact with items an infected person has touched, such as bed linens, towels, toys and clothing. In adults, it may be contracted after an upper respiratory infection such as a virus. Crowded conditions and contact sports increase the likelihood of contracting the disease.