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Impetigo Overview

Impetigo is a superficial skin infection caused by Streptococcus pyogenes. See more pictures of skin problems.
Craig Zuckerman/Visuals Unlimited/Getty Images

Do you have an itch that you can't quite scratch? Or an itch that seems to spread whenever you scratch it? If so, you may have impetigo, a bacterial skin infection characterized by red sores, blisters and an itchy rash. Impetigo often occurs in infants and children whose developing immune systems make them more vulnerable to infection, but adults can also develop it. And while impetigo generally appears around the nose and mouth, it can occur anywhere skin has been damaged or broken, such as by a cut, scrape or mosquito bite [source: Cronan].

There are many types of impetigo, but all of them are highly contagious and cause blisters that ooze pus, which dries to form a honey-colored crust. Impetigo contagiosa, the most common type, often begins as a red spot on the face that ruptures and scabs over. Bullous impetigo affects mostly young children and appears as blisters on the arms, legs and torso. Ecthyma is the most serious and painful type of impetigo because the infection penetrates deep into the skin and causes ulcers that may scar [source: Mayo Clinic]. However, most cases of impetigo, while unpleasant, aren't painful and won't produce scars.

Read on to learn what causes impetigo.