Related concepts:

Bullous impetigo, Nonbullous impetigo, Skin infections, Staph impetigo, Strep impetigo.

Introduction to impetigo:

Healthy skin is remarkably resistant to infection. It is a powerful barrier, keeping the billions of bacteria outside and your child on the inside. The outer layer, called the stratum corneum or horny layer, is a thin, flexible coat of armor made of the same material as a rhinoceros's horn. The stratum corneum is constantly growing and shedding, moving bacteria outwards. The moving barrier is only completely effective when the skin is dry.

This thin armor can be breached by insect bites, by minor cuts and scrapes, by patches of eczema, or by chronically wet skin from hot muggy weather or hot clothes (diapers). Areas of skin that are red and inflamed, perhaps from rubbing, from a runny nose, or from drool, have a disrupted stratum corneum.

When bacteria enter the skin through a chink in this armor, an infection can result.

What is impetigo?

Impetigo is a contagious bacterial infection of the skin. Parents often describe it as a rash.

Two types of bacteria are the main culprits. Most of the time, streptococcus bacteria (the ones also responsible for strep throat and scarlet fever) or staphylococcus (staph) bacteria cause of impetigo.

Who gets impetigo?

Impetigo is by far most common in infants and young children. They have more colds, more fingers in the nose, more small cuts and scrapes, and more insect bites – all allowing the bacteria to get in.

Children with eczema are even more prone to impetigo.

Chickenpox is a classic time to get impetigo. The pox provide a place for the bacteria to enter the skin and the scratching moves the bacteria inside. That’s one of the reasons why your mother told you not to scratch!

What are the symptoms of impetigo?

There are two classic forms of impetigo -- with blisters (bullous impetigo) and without blisters (nonbullous impetigo).

Fluid-filled blisters can form on the face, trunk, limbs, or in the diaper area. The blisters break and leak easily, leaving a thin rim of dead skin around a raw, moist sore that may form a scab. Staph is almost always the cause of bullous impetigo.

Impetigo without blisters is most common near the nose, mouth, or ears, but it can occur anywhere on the body. It usually begins as a small red patch or a pimple, which spreads to a larger honey-crusted sore. The infection can spread under the skin and pop up at distant sites. It can also spread to other parts of the body by fingers, clothes, or towels.

This type of impetigo sometimes itches. There may be swollen glands nearby. This type of impetigo is also most commonly caused by staph, but strep are a frequent cause. The staph usually comes from the nose. By contrast, the strep usually arrives on the skin first, causes impetigo, and then may cause strep throat or other strep infections (even kidney disease).

Is impetigo contagious?

Impetigo is quite contagious.