What Is Impetigo?
Impetigo is a highly contagious bacterial skin infection. It can appear anywhere on the body but usually attacks exposed areas. Children tend to get it on the face, especially around the nose and mouth, and sometimes on the arms or legs. The infected areas appear in plaques ranging from dime to quarter size, starting as tiny blisters that break and expose moist, red skin. After a few days, the infected area is covered with a grainy, golden crust that gradually spreads at the edges.
In extreme cases, the infection invades a deeper layer of skin and develops into ecthyma, a deeper form of the disease. Ecthyma forms small, pus-filled bumps with a crust much darker and thicker than that of ordinary impetigo. Ecthyma can be very itchy, and scratching the irritated area spreads the infection quickly. Left untreated, the sores may cause permanent scars and pigment changes.
The gravest potential complication of impetigo is post-streptococcal glomerulonephritis, a severe kidney disease that occurs following a strep infection in less than 1% of cases, mainly in children. The most common cause of impetigo is Staphylococcus aureus. However, another bacteria source is group A streptococcus. These bacteria lurk everywhere. It is easier for a child with an open wound or fresh scratch to contract impetigo. Other skin-related problems, such as eczema, body lice, insect bites, fungal infections, and various other forms of dermatitis can make a person susceptible to impetigo.
Most people get this highly infectious disease through physical contact with someone who has it or from sharing the same clothes, bedding, towels, or other objects. The very nature of childhood, which includes lots of physical contact and large-group activities, makes children the primary victims and carriers of impetigo.
What Are the Signs of Impetigo?
Impetigo starts out as a small cluster of blisters that after a few hours breaks into a red, moist area that oozes or weeps fluid. Impetigo appears mainly on the face but also can develop on exposed areas of the arms and legs.
In a few days, there is the formation of a golden or dark-yellow crust resembling grains of brown sugar. The infection may continue to spread at the edges of the infected area or affect other areas of skin.
Impetigo can be spread by skin-to-skin or infected surface-to-skin (such as towels) contact.
Call Your Doctor About Impetigo if:
- You have sores or a rash that worsens or becomes more uncomfortable. An impetigo infection needs prompt medical attention.
- Small, pus-filled sores form, with a dark brown crust. This indicates ecthyma, a deeper form of skin infection that penetrates into the skin. If left untreated, it may cause scarring and permanent changes in skin pigmentation.
What Are the Treatments for Impetigo?
The key to treating — and preventing — impetigo is to practice good personal hygiene and maintain a clean environment. Once the infection occurs, prompt attention will keep it under control and prevent it from spreading.
Even if only one family member has impetigo, everyone in the household should follow the same sanitary regimen. Wash regularly with soap and water. This should help clear up mild forms of the infection. If this does not help, seek care from your doctor. You may need a prescription medication. Topical mupirocin ointment, available only by prescription, is highly successful in treating mild forms of the infection. Don’t try over-the-counter antibacterial ointments; they are too weak to kill strep and staph infections, and applying the ointment carelessly may actually spread the impetigo. If you have a more severe infection, you may need to take oral antibiotics.
Anyone in a household who develops impetigo should use a clean towel with each washing. Be sure to launder those towels separately. Keep sores covered to prevent spread of the infection to other parts of the body or other people.