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Impetigo

Definition

Impetigo is a common skin infection.

Causes, incidence, and risk factors

Impetigo is caused by streptococcus (strep) or staphylococcus (staph) bacteria. Methicillin-resistant staph aureus (MRSA ) is becoming a common cause.

The skin normally has many types of bacteria on it. When there is a break in the skin, bacteria can enter the body and grow there. This causes inflammation and infection. Breaks in the skin may occur with:

  • Animal bites
  • Human bites
  • Injury or trauma to the skin
  • Insect bites

Impetigo may also occur on skin where there is no visible break.

It is most common in children who live in unhealthy conditions. 

In adults, it may occur following another skin problem. It may also develop after a cold or other virus.

Impetigo can spread to others. You can catch the infection if the fluid that oozes from the blisters touches an open area on your skin.

Symptoms

Symptoms of impetigo are:

  • One or many blisters filled with pus that are easy to pop. In infants, the skin is reddish or raw-looking where a blister has broken. 
  • Blisters that itch:
  • that may begin as a single spot, but spreads to other areas with scratchingRash
  • on the face, lips, arms, or legs, that spread to other areasSkin sores
  • Swollen lymph nodes near the infection ()

Signs and tests

Your health care provider will look at your skin to determine if you have impetigo.

The health care provider may take a sample of bacteria from your skin to grow in the lab.This can help determine if MRSA is the cause. Specific antibiotics are needed to treat this type of bacteria.

Treatment

The goal is to cure the infection and relieve the symptoms.

Your doctor will prescribe an antibacterial cream. You may need to take antibiotics by mouth if the infection is severe.

Wash (do not scrub) the skin several times a day with an antibacterial soap to remove crusts and drainage.

Support Groups

Expectations (prognosis)

The sores of impetigo heal slowly. Scars are rare. The cure rate is very high, but the problem often comes back in young children.

Complications

  • (post-streptococcal Kidney failure ) (rare)glomerulonephritis
  • Many patches of impetigo (in children)
  • Permanent skin damage and scarring (very rare)
  • Spread of the infection to other parts of the body (common)

Calling your health care provider

Call your health care provider if you have symptoms of impetigo.

Prevention

Prevent the spread of infection.

  • If you have impetigo, always use a clean washcloth and towel each time.
  • Do not share towels, clothing, razors, and other personal care products with other family members.
  • Avoid touching blisters that are oozing.
  • Wash your hands thoroughly after touching infected skin.

Keep your skin clean to prevent getting the infection. Clean minor cuts and scrapes well with soap and clean water. You can use a mild antibacterial soap. 

References

Habif TP. Bacterial infections. In: Habif TP, ed. . 5th ed. St. Louis, Mo: Mosby Elsevier; 2009:chap 9.

Pasternack MS, Swartz MN. Cellulitis, necrotizing fasciitis, and subcutaneous tissue infections. In: Mandell GL, Bennett JE, Dolin R, eds. . 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 90.

Morelli JG. Cutaneous Bacterial Infections. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. . 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 657.

Encyclopedia content is provided as information only and not intended to replace the advice and instruction from your personal physician.