Impetigo is a skin infection. It often appears as blisters around the mouth and nose, but it can infect skin anywhere on the body. Impetigo can easily spread from one person to another. This infection occurs most often in children.
Impetigo: Sores on the Upper Lip
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Impetigo is caused by bacteria. The most common type of bacteria associated with this infection includes:
These types of bacteria are normally found on the skin and in the nose. The bacteria do not cause trouble until it gets under the skin. Bacteria get in under the skin through small cuts, scratches, or insect bites.
This condition is more common in preschool and school-aged children.
Factors that may increase your chances of impetigo:
Symptoms of impetigo appear 4-10 days after contact with the bacteria.
The main signs of impetigo are skin lesions. They occur most often on the face, arms, or legs but can appear anywhere on the body. The lesions may be red spots, sores, or blisters. The lesion may:
There may also be swollen lymph nodes in the area with more serious infections.
Impetigo is normally a fairly mild condition. However, further problems could develop if it is not treated. The infection could spread. This can lead to pain, swelling, pus, or fever. Rarely, impetigo that is caused by Group A streptococcus may develop into:
You will be asked about your symptoms and medical history. The skin lesions will be examined. Your doctor will be able to diagnose impetigo by the look of your skin lesions.
A sample of the infected skin may be tested. This will show what specific bacteria are causing the infection. It may help to guide treatment choices.
The goals of treatment are to relieve the symptoms and cure the infection.
Treatment may include:
Antibiotics are a type of medication that can fight bacteria. For a mild infection, your doctor may advise:
Your doctor may prescribe oral antibiotics for more severe or widespread infections.
In some cases, staphylococcal infections (such as methicillin-resistant Staphylococcus aureus [MRSA]) may be resistant to these antibiotics. Others options may be needed.
Good skin care is important with this type of infection. It can help prevent the spread of the infection to other areas of your skin or to others. In general:
To help avoid spreading the infection:
Prevention of impetigo involves good personal hygiene:
American Academy of Dermatology
Kids Health—Nemours Foundation
Canadian Dermatology Association
Impetigo. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T115810/Impetigo . Updated October 27, 2017. Accessed February 15, 2018.
Impetigo. Kids Health—Nemours Foundation website. Available at:
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Updated June 2014. Accessed February 15, 2018.
10/6/2014 DynaMed Plus Systematic Literature Surveillance http://www.dynamed.com/topics/dmp~AN~T115810/Impetigo : Hartman-Adams H, Banvard C. Impetigo: diagnosis and treatment. Am Fam Physician. 2014;90(4):229-235.
Last reviewed March 2018 by
EBSCO Medical Review Board
David L. Horn, MD, FACP
Last Updated: 10/6/2014