Impetigo

Definition

Impetigo is a skin disorder caused by bacterial infection and characterized by crusting skin lesions.

Causes

Impetigo is a common skin infection. It is most common in children, particularly children in unhealthy living conditions. In adults, it may follow other skin disorders. Impetigo may follow a recent upper respiratory infection such as a cold or other viral infection. It is similar to cellulitis, but is more superficial, involving infection of the top layers of the skin with streptococcus (strep), staphylococcus (staph), or both.

The skin normally has many types of bacteria on it, but intact skin is an effective barrier that keeps bacteria from entering and growing within the body. When there is a break in the skin, bacteria can enter the body and grow there, causing inflammation and infection. Breaks in the skin may occur with insect bites, animal bites, or human bites, or other injury or trauma to the skin. Impetigo may occur on skin where there is no visible break.

Impetigo begins as an itchy, red sore that blisters, oozes and finally becomes covered with a tightly adherent crust. It tends to grow and spread. Impetigo is contagious. The infection is carried in the fluid that oozes from the blisters. Rarely, impetigo may form deeper skin ulcers.

Symptoms

• Skin lesion on the face or lips, or on the arms or legs, spreading to other areas. Typically this lesion begins as a cluster of tiny blisters which burst, followed by oozing and the formation of a thick honey- or brown-colored crust that is firmly stuck to the skin.
• Itching blister:
  • Filled with yellow or honey-colored fluid
  • Oozing and crusting over
• Rash (may begin as a single spot, but if person scratches it, it may spread to other areas).
• In infants, a single or possibly multiple blisters filled with pus, easy to pop and -- when broken -- leave a reddish raw-looking base.
• Lymphadenopathy -- local lymph nodes near the infection may be swollen.

Exams and Tests

Diagnosis is based primarily on the appearance of the skin lesion. A culture of the skin or mucosal lesion usually grows streptococcus or staphylococcus.

Treatment

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

A mild infection may be treated with a prescription antibacterial cream. More severe cases may require antibiotics, taken by mouth.

Wash the skin several times a day, preferably with an antibacterial soap, to remove crusts and drainage.

Outlook (Prognosis)

The sores of impetigo heal slowly and seldom scar. The cure rate is extremely high, but they often come back in young children.

Possible Complications

• The infection could spread to other parts of the body. This is common.
• Children often have multiple patches of impetigo.
• A systemic infection could lead to kidney failure (post-streptococcal glomerulonephritis). This is a rare occurrence.
• Permanent skin damage and scarring may occur (also extremely rare).

When to Contact a Medical Professional

Call for an appointment with your health care provider if symptoms indicating impetigo are present.

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 so on with other family members. Wash the hands thoroughly after touching the skin lesions.

Good general health and hygiene help to prevent infection. Minor cuts and scrapes should be thoroughly cleansed with soap and clean water. A mild antibacterial agent may be used, if desired.

Impetigo is contagious, so avoid touching the draining (oozing) lesions.