Although the bacteria that cause them may vary, bacterial skin infections often are the result of skin that has been wounded, scraped or cut open. This opening in the body's natural barrier allows bacteria to enter and grow, causing the infection. Those with certain medical conditions, including diabetes and AIDS, also are at greater risk of infection. Healthy people can still develop infections, although it is less common.
People who leave their hands exposed while working with bacteria-contaminated materials, such as meat and poultry, are at particular risk for cellulitis [source: WebMD]. It is usually caused by one of two of the most common strains of bacteria: Streptococcus pyogenes (strep) or Staphylococcus aureus (staph). This infection can appear either on its own or as a result of a wound or cut that becomes infected.
Folliculitis tends to strike those who use poorly maintained pools or hot tubs, wear tight clothing, overuse antibiotics or steroid creams, or have existing infected injuries or wounds [source: WebMD]. Folliculitis is normally caused by the bacteria Staphylococcus.
Boils or carbuncles tend to strike people who are in close proximity to someone who is infected, those who already have other skin conditions such as acne or dermatitis or those who have a weakened immune system [source: Mayo Clinic]. Poor hygiene also can contribute to boil or carbuncle infections, which are caused by the bacteria Staphylococcus [source: WebMD].
Impetigo most commonly affects infants in addition to children between the ages of 2 and 6, but adults can also get it. You are more likely catch impetigo if you have skin-to-skin contact with an infected person, have contact with an towels or clothing used by an infected person, or have pre-existing skin conditions [source: Mayo Clinic]. Conditions that have already irritated skin, including eczema, poison ivy, burns or bug bites, make it easier for the bacteria to enter [source: WebMD]. Impetigo can be caused by either Staphylococcus or Streptococcus.
The good news is that treatments are available. Read on to learn what can be done to clear up infections.