What is impetigo?
Impetigo (say "im-puh-TY-go") is a bacterial skin infection. It causes red sores that can break open, ooze fluid, and develop a yellow-brown crust. These sores can occur anywhere on the body.
Impetigo is one of the most common skin infections in children. It can occur in adults but is seen far more often in children. Impetigo is contagious and can be spread to others through close contact or by sharing towels, sheets, clothing, toys, or other items. Scratching can also spread the sores to other parts of the body.
What causes impetigo?
Impetigo is caused by one of two kinds of bacteria—strep (streptococcus) or staph (staphylococcus). Often these bacteria enter the body when the skin has already been irritated or injured because of other skin problems such as eczema, poison ivy, insect bites, burns, or cuts. Children may get impetigo after they have had a cold or allergies that have made the skin under the nose raw. But impetigo can also develop in completely healthy skin.
What are the symptoms?
You or your child may have impetigo if you have sores:
- That begin as small red spots, then change to blisters that eventually break open. The sores are typically not painful, but they may be itchy.
- That ooze fluid and look crusty.
- That increase in size and number. Sores may be as small as a pimple or larger than a coin.
How is impetigo diagnosed?
Your doctor can usually diagnose impetigo just by looking at your or your child's skin. Sometimes your doctor will gently remove a small piece of a sore to send to a lab to identify the bacteria. If you or your child has other signs of illness, your doctor may order blood or urine tests.
How is it treated?
Impetigo is treated with antibiotics. For cases of mild impetigo, a doctor will prescribe an antibiotic ointment or cream to put on the sores. For cases of more serious impetigo, a doctor may also prescribe antibiotic pills.
A child can usually return to school or daycare after 24 hours of treatment. If you apply the ointment or take the pills exactly as prescribed, most sores will be completely healed in 1 week.
At home, gently wash the sores with clean water each day. If crusts form, your doctor may advise you to soften or remove the crusts. You can do this by soaking them in warm water and patting them dry. This can help the cream or ointment work better.
After you touch the area, wash your hands with soap and water or use an alcohol-based hand sanitizer.
Try not to scratch the sores, because scratching can spread the infection to other parts of the body. You can help prevent scratching by keeping your child's fingernails short. You can cover the sores with a loose bandage. The sores need air to heal.
Call your doctor if you or your child do not get better as expected or if you notice any signs that the infection is getting worse such as fever, increased pain, swelling, warmth, redness, or pus.
How can impetigo be prevented?
If you know someone who has impetigo, try to avoid close contact with that person until his or her infection has gone away. Do not share towels, sheets, or clothes until the infection is gone. Wash anything that may have touched the infected area.
If you or your child has impetigo, scratching the sores can spread the infection to other areas of your body and to other people. Wash your or your child's hands with soap to help prevent spreading the infection.
Other Works Consulted
- American Academy of Pediatrics (2015). Recommendations for inclusion or exclusion. In DW Kimberlin et al., eds., Red Book: 2015 Report of the Committee on Infectious Diseases, 30th ed., pp. 136–137. Elk Grove Village, IL: America Academy of Pediatrics.
- Craft N (2012). Superficial cutaneous infections and pyodermas. In LA Goldman et al., eds., Fitzpatrick's Dermatology in General Medicine, 8th ed., vol. 2, pp. 2128–2147. New York: McGraw-Hill.
- Habif TP (2010). Bacterial infections. In Clinical Dermatology, A Color Guide to Diagnosis and Therapy, 5th ed., pp. 335–381. Edinburgh: Mosby Elsevier.
- Morelli JG (2011). Cutaneous bacterial infections. In RM Kliegman et al., eds., Nelson Textbook of Pediatrics, 19th ed., pp. 2299–2308. Philadelphia: Saunders.
Current as of: August 22, 2019
Author: Healthwise Staff
Medical Review: Susan C. Kim, MD - Pediatrics
Brian O'Brien, MD, FRCPC - Internal Medicine
Adam Husney, MD - Family Medicine
Kathleen Romito, MD - Family Medicine
John Pope, MD, MPH - Pediatrics