An organism that lives on or in human skin and takes nourishment from its human host is considered a skin parasite. Some organisms, such as mosquitoes, fleas and bedbugs, get nourishment from biting a human but do not actually live on or in the skin. True parasites commonly living on skin include lice, mites, ticks, bacteria and fungus.
Lice
Three different species of lice affect humans: head, body and pubic lice. These tiny creatures have no wings and cannot hop or jump but spread by close personal contact. Head lice spread by sharing hats, helmets, combs and other headgear. Body lice infest humans from contaminated bedding and clothing, while pubic lice infest the genital area during sexual contact. Use commercial remedies to eliminate this pest, consulting a physician or pharmacist for the best choice.
Mites
Mites either happily coexist or cause great discomfort to human skin. Demodex, or face mites, live in pores and hair follicles. Most humans carry a few of these with no ill effects. Chigger mite larvae live on soil and vegetation, grasping at a host as it walks by. They inject skin-digesting saliva, which causes severe itching. If not removed, the mite will feed for several days. No treatment is necessary for Demodex or chiggers.
Scabies Mites
Scabies is the most common condition resulting from mite infestation. The American Osteopathic College of Dermatology estimates that over 300 million scabies cases occur every year. This mite is spread by person-to-person or animal-to-person contact. They burrow into the skin to lay eggs. Larvae hatch and travel to the surface, causing severe itching. It usually appears in skin folds and crevices such as under the arms, between fingers and at the belt line. Prescribed medications eliminate mites and reduce itching.
Ticks
Tiny biting insects called ticks burrow their heads into human skin and feed on blood. They live in tall grass and wooded areas grasping a host as it walks by. Most tick bites do not cause symptoms, but ticks may be infected with bacteria, viruses or protozoa. Lyme disease and Rocky Mountain spotted fever are transmitted through tick bites. Remove ticks by gripping them with tweezers near the head and pulling slowly. Symptoms of tick-borne illness occur 1 to 4 weeks after a tick bite.
Fungus
Since a parasite is any organism living on another, it includes fungi. Fungus lives on human skin as ringworm, athlete's foot and jock itch. Fungal infections come from contaminated objects and infected persons. It appears in areas of the body experiencing increased heat and perspiration, such as armpits, groin, feet and breasts. Ringworm grows as itchy patches in ring-shaped patterns and can affect fingernails due to scratching. Over-the-counter antifungal medications usually eliminate any fungus.
Bacteria
Many types of bacteria normally occupy the skin, but when bacteria invade damaged skin and multiply dramatically, they create an infection. Therefore, the bacteria live as a parasite within the wound. Primary parasites, such as fungus or mites, penetrate the skin and itching further damages it. The bacteria invade the area and cause a secondary bacterial infection. Two separate treatments must be used--one for the primary condition and one for the bacteria.
