The skin provides a remarkably good barrier against bacterial infections. Although many bacteria come in contact with or reside on the skin, they are normally unable to establish an infection. When bacterial skin infections do occur, they can range in size from a tiny spot to 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 preexisting skin disorders. People can develop bacterial skin infections when participating in a variety of activities, for example, gardening in contaminated soil or swimming in a contaminated pond, lake, or ocean.
Classification and Causes
Some infections involve just the skin, and others also involve the soft tissues under the skin. Relatively minor infections include
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Small skin abscesses (pus-filled pockets in the skin)
More serious bacterial skin and skin structure infections include
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Large skin abscesses
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Wound infections
Many types of bacteria can infect the skin. The most common are Staphylococcus and Streptococcus. Methicillin-resistant Staphylococcus aureus (also known as MRSA), which is resistant to many commonly used antibiotics, is now the most common bacteria causing skin infections in the United States. One particular strain of MRSA has caused more than half of all community-associated skin and soft tissue infections treated in the United States. Because MRSA is resistant to several antibiotics, 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
Some people are at particular risk of developing skin infections:
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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
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People who are hospitalized or living in a nursing home
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People who are older
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People who have human immunodeficiency virus (HIV), AIDS or other immune disorders, or hepatitis
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People who are undergoing chemotherapy or treatment with other drugs that suppress the immune system
Skin that is inflamed or damaged is more likely to become infected. In fact, any break in the skin predisposes a person to infection.
Prevention
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.
Petrolatum may be applied to open areas to keep the tissue moist and to try to prevent bacterial invasion. 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.
