Human skin is susceptible to infection by a multitude of different organisms.
Cellulitis occurs when a break in the skin allows bacteria to enter the body. This may occur after injury or a medical procedure. Bacterial infections are typically diagnosed with a simple culture, and they may be treated with topical or oral antibiotics. While not usually serious, it is possible for bacterial skin infections to progress deeper into the tissues or into the bloodstream.
Viral infections are common in childhood, though vaccines may help some children avoid chicken pox, measles, and mumps. Herpes simplex virus (HSV) may cause repeated flares of cold sores or genital herpes. Wart viruses cause benign, proliferating bumps in the skin. Shingles is caused by a recurrence of the chicken pox virus later in life. Occasionally, short-lived viral infections may cause a widespread skin rash. Viral cultures and skin biopsies are useful in diagnosing the above conditions while treatment includes oral antiviral medications, oral corticosteroids, or supportive care.
Most fungal infections take the form of athlete’s foot, “jock itch,” or ringworm, which are all caused by the same fungus living in the outer layers of the skin. It is usually easily treated with topical creams, but more widespread infections are cleared with oral antifungals. Yeast infections occur in warm, moist areas that include the mucosal skin of the mouth or vagina, as well as skin folds in the groin and under the breasts.
Scabies are microscopic mites that live in the outer layers of the skin. They cause itching and irritation and they may be difficult to correctly identify without microscopic examination of skin scrapings. Scabies are highly contagious and many individuals experience a delay in diagnosis. They are readily treated with oral and topical medications, though all of a person’s close contacts need to be treated to achieve lasting resolution. Body lice, while not microscopic, cause similar itching and skin irritation in hair-bearing areas.
Early identification of skin infections can lead to more rapid relief of symptoms, lessen the risk of serious complications, and ensure that the infection does not spread to others.