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What is Impetigo

What is Impetigo

Impetigo (imm-pet-eye-go) is an infection of the upper layer of the skin that is very common in younger children. Common bacteria usually cause impetigo. The most common is Strep, similar to the germ that causes Strep throat. Sometimes a germ called Staph (staff) causes impetigo. Impetigo usually starts from an area of broken skin, very often from around a bug bite or a scratch. It also commonly starts underneath the nose from repeated rubbing and abrasion from facial tissue during a cold. Children often scratch, pick, or rub at their skin. This is a very effective way of getting the germs into the skin. Once the infection has started, it can spread very rapidly from the first sore to other areas of the body.

Impetigo usually looks like red, sore skin with a “honey-colored” crust on the surface. It can be painful and/or itchy. The skin may ooze fluid or blood if someone breaks or disturbs the crust. Rarely, the impetigo infection can go deeper into the skin and cause infection of the fat in the lower layers. You can read our Children’s Health Topic and Aftercare Instructions on this condition, which is called “cellulitis.”

Impetigo is very contagious (catching). It can spread rapidly through preschools, daycare, and kindergartens. If your child has impetigo, please keep him or her home until the rash has cleared up and no new sores appear.

What is the biggest concern?

Our biggest concern in impetigo is to prevent the infection from getting worse. It can spread to other parts of the child’s body or to other children. Some types of the Strep germ that causes impetigo can also cause kidney damage, so we need to treat impetigo promptly. We also want to relieve the itching and keep the rash cleaned up.

Impetigo treatment

Because bacteria cause impetigo, doctors treat it with antibiotics. For small areas of impetigo, your doctor may recommend only local care and a prescription antibiotic ointment such as mupirocin (Bactroban® and others). Over-the-counter antibiotic ointments such as bacitracin, polysporin, and neomycin do not work well in impetigo. If your child has larger areas or many areas of impetigo, s/he will need to take an oral antibiotic (see our article  on oral medications). Some doctors may recommend an injection of an antibiotic.

Doctors use antibiotics such as amoxicillin-clavulanic acid (Augmentin® and others), or one of the many drugs called “cephalosporins” (seff-ah-low-spore-ins) to treat children with impetigo. These include drugs such as Cefzil®, Keflex®, Vantin®, and many others. Children with allergies to the penicillin-like drugs should take erythromycin (many trade names) or azithromycin (Zithromax®). Please be sure to give your child the medicine for the entire time it is prescribed. If you stop the antibiotic too early, the germs can become resistant to it. Stopping antibiotics early can also make kidney or heart damage more likely.

You can do some other things to help your child feel more comfortable and to prevent the impetigo from spreading. You can give your child diphenhydramine (dye-fen-hi-drah-meen; Benadryl® and many others) for itch relief. The main side effect of diphenhydramine is drowsiness, which is actually often helpful to a child whose itching is making him or her frantic. Please do not use diphenhydramine in topical lotions.

You can reduce the amount of germs on your child’s skin and in the sores by gently washing the sores several times each day. One of the best ways to do this is to use a rich lather of a pure soap such as Ivory® or any other soap that does not contain fragrance or deodorants. Lather up a washcloth with the soap, and then gently wash the area. Try to soak off the crusting material, which is where the germs live. After washing and soaking, please rinse the skin and gently pat it dry. Launder the soiled washcloth and towel after each use, to be sure you keep the germs away. If your doctor has prescribed an ointment, you can apply that now. It is best not to cover the sores unless they are oozing or the child scratches or picks them. If you do cover them, please use a dry sterile gauze pad and tape it only at the edges. It is good for air to be able to reach the skin.

Please keep your child home from school, daycare, or camp until the rash has completely cleared up and no new sores appear. This will give you more opportunities to cleanse the sores, and will prevent your child from spreading the infection to others. If your child is old enough, please remind him or her to wash his or her hands frequently to prevent spreading the germs.

When should I be worried?

With proper skin care and antibiotics, impetigo usually clears up completely in 5 – 7 days. If it seems to be lasting longer or continues to spread, please check with your doctor; it may be necessary to change the medication. Sometimes impetigo can cause a more severe infection such as cellulitis. Here are some things to look out for:

  • Fever
  • Sores that appear very close to the eyes
  • Spreading redness away from the impetigo sores to healthy skin
  • Pain or swelling of the skin in areas away from the sores
  • Difficulty moving a joint in the area of the rash

Impetigo can cause kidney problems from certain types of bacteria. These problems usually do not appear until some days or weeks after the infection has cleared up. Here are some of the things to look out for:

  • Pain in the abdomen or low back
  • Change in the color or appearance of the urine
  • Puffy hands, feet, or face

If any of these things occur, please be sure to call your doctor right away.

Other points of concern

Although impetigo most often appears as we described above, it can sometimes form medium to large blisters. This is called “bullous impetigo,” which is easy to mistake for a burn or other injury. The germ Staph causes most cases of bullous impetigo. Doctors treat it the same way as other impetigo, once they are sure of the diagnosis.

When Strep germs cause impetigo, they can cause some serious, though rare, complications. Rheumatic fever is a reaction that occurs when the body tries to fight the Strep germ. It can cause joint and heart disease. It is very rare today because doctors use antibiotics. If children finish their whole course of antibiotics, they almost never get rheumatic fever. A kidney disease called “nephritis” (neff-rye-tiss) can happen after infection with certain types of Strep. Although it is usually temporary, some children can have long-term kidney damage after nephritis. Infections with the Strep that causes nephritis usually happen in outbreaks, and public health authorities usually issue warnings when they learn of an outbreak.

Other Conditions that Might Be Present with Impetigo

Impetigo usually has a typical appearance and not many other things look like it. Real burnscan have blisters that look a bit like bullous impetigo. Burns are usually very painful. Most of the time a child can tell someone that they were burned. Unfortunately, some people cause harm to children intentionally. Most doctors have seen children with cigarette burns, which can look just like bullous impetigo without a careful look. If your child has round blisters that are all the same size and age, please be sure you discuss this with your doctor.