The skin provides a remarkably good barrier against bacterial infections. Although many bacteria come in contact with or reside on the skin, they normally do not cause an infection. When bacterial skin infections do occur, they can range in size from a tiny spot to spots or sores over the entire body surface. They can range in seriousness as well, from harmless to life threatening.
Bacterial skin infections develop when bacteria enter through hair follicles or through small breaks in the skin that result from scrapes, punctures, surgery, burns, sunburn, animal or insect bites, wounds, and pre-existing skin disorders. People can develop bacterial skin infections after participating in a variety of activities, for example, gardening in contaminated soil or swimming in a contaminated pond, lake, or ocean.
Classification of Bacterial Skin Infections
Some infections involve just the skin, and others also involve the soft tissues under the skin. Relatively minor infections include:
Small skin abscesses (pus-filled pockets in the skin)
More serious bacterial skin and skin structure infections include:
Large skin abscesses
Wound infections
Staphylococcal scalded skin syndrome, scarlet fever, and toxic shock syndrome are skin-related complications of bacterial infections.
Causes of Bacterial Skin Infections
Many types of bacteria can infect the skin. The most common are Staphylococcus and Streptococcus.
Methicillin-resistant Staphylococcus aureus (also known as MRSA) is a common bacteria that causes skin infections in the United States. MRSA is resistant to many commonly used antibiotics because it has undergone genetic changes that allow it to survive despite exposure to some antibiotics. Because MRSA is resistant to several antibiotics that used to kill it, doctors tailor their treatment based on how often MRSA is found in the local area and whether or not it has been found to be resistant to commonly used antibiotics.
Risk Factors for Bacterial Skin Infections
Some people are at particular risk of developing skin infections:
People with diabetes, who are likely to have poor blood flow (especially to the hands and feet), have a high level of sugar (glucose) in their blood, which decreases their ability to fight infections
People who are hospitalized or living in a nursing home
People who are older
People who have human immunodeficiency virus (HIV), AIDS or other immune disorders, or hepatitis
People who are undergoing chemotherapy or treatment with other medications that suppress the immune system
Children under 5 years of age
Adults over 85 years of age
Skin that is inflamed or damaged is more likely to become infected. In fact, any break in the skin predisposes a person to infection.
Children under 5 years of age and adults over 85 years of age are at a particularly higher risk of developing a bacterial skin infection.
Treatment of Bacterial Skin Infections
Antibiotics
Drainage of abscesses
Doctors prescribe an antibiotic ointment for minor skin infections. They prescribe antibiotics that are taken by mouth (orally) or given by vein (intravenously) if a large area of skin is infected.
Abscesses are often cut open (incised) by doctors and allowed to drain, and they surgically remove any dead tissue.
Prevention of Bacterial Skin Infections
Cleaning skin with soap and water
Preventing bacterial skin infections involves keeping the skin undamaged and clean. When the skin is cut or scraped, the injury should be washed with soap and water and covered with a sterile bandage.
Petroleum jelly may be applied to areas where small wounds are open or where the skin has peeled off to keep the tissue moist and to try to keep bacteria out. Doctors recommend that people do not use antibiotic ointments (prescription or nonprescription) on uninfected minor wounds because of the risk of developing an allergy to the antibiotic.
