Scabies

Scabies is a common infestation of microscopic parasites that infest the top layer of skin. Scabies is also called mites, and is caused by the parasite Sarcoptes scabiei. People are usually infested by scabies from prolonged skin to skin contact. After a person has been infested, the female parasite burrows into the skin and lays eggs. In about ten days, the eggs hatch. Scabies can be cured with lotions.

Symptoms of scabies can include an intense itching, burrows, skin irritation, and rashes. People with weakened immune systems could experience these symptoms more severely.

Transmission

Scabies is transmitted through prolonged skin to skin contact. Transmission can occur during sexual contact, but it is more likely to occur when sexual partners spend the night together than from brief sexual activity. Transmission can also occur during nonsexual contact. Contact between people that is prolonged can cause transmission, although brief casual contact like hugging or shaking hands is not likely to be a cause.

Prolonged contact with infested bedding, clothing, or furniture can be a possible cause of transmission. Contact with objects like a toilet seat is not likely to be a cause.

Scabies can not be transmitted from pets to human. The type of scabies that infest humans is different than the type that infests animals.
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Symptoms

The first time people are infested with scabies, symptoms can take four to six weeks to occur. After being treated, people who are infested with scabies again, can have symptoms occur within one to four days.

Symptoms can be pimple-like irritations, mite burrows that can be in an “S” or zigzag shape, or a rash of the skin. These symptoms can usually be found on the webbing between the fingers and the sides of the fingers, armpits, skin folds of the elbows and knees, wrists, breasts, naval, waist or abdomen, lower part of the buttocks, scrotum, penis, or the groin area.

Another symptom is intense itching that can be experienced over most of the body and is worse at night. Aggressive scratching at it can cause sores.
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Testing / Diagnosis

Scabies infestations can be diagnosed by taking a skin scraping from one of the burrows, pimple-like irritations, or rashes and looking at it under a microscope. Finding eggs, mites, or mite fecal matter would confirm a scabies infestation. However, seeing none of these does not mean someone is free of scabies. Usually people infested with scabies will have fewer than ten mites on their entire body, making scabies easy to miss.

Another test that could be performed is called a Burrow Ink Test (BIT). The area where an infestation is thought to be is rubbed with fountain pen ink. The area is then wiped off with an alcohol pad. If a zigzag or “S” shape appears, that means there is an infestation of scabies.

Using a needle to extract the mites from a burrow is a test that can also be performed. This involves inserting a needle carefully into the length of a burrow, extracting the mite, then placing the mite on a slide to be viewed under a microscope.

A health care provider will decide which of these testing options is best, based on the patient’s needs.
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Treatment

There are several options available to kill scabies. The recommended method is Permethrin cream (RID®; A-200®). The cream should be applied to a body that has been cleaned, in a thin layer, from the neck down to the toes. It should be left on for at least eight hours, and then washed off. Lindane (Kwell®) is another treatment option, which is only available with a prescription. This cream should also be applied to a body that has been cleaned, in a thin layer, from the neck down to the toes. After eight hours, it should be washed off. However, it should not be used by pregnant or lactating women, young children, people with seizure disorders, or used on broken skin or right after bathing (wait a while after bathing to apply). Scabies can also be treated orally with the medication Ivermectin. However, it should not be used by pregnant or lactating women.

It is important to remember, with any medication, over the counter or prescription, always follow the directions on the label or the instructions given by the prescribing health care provider.

These treatment options should kill the scabies. However, symptoms can remain for two to three weeks. After treatment, people should make sure to use clean bedding, clothing, towels, etc. If they do not, they could become infested again.
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Complications

In most healthy people, the worst that can occur from scabies is scratching too aggressively at the itching and causing sores that could develop bacterial infections.

People who have a weakened immune system could develop what is known as Norwegian or crusted scabies. With Norwegian scabies, a person can be infested with thousands to millions of mites. This will cause the skin symptoms to be much more severe. The larger number of mites also makes it easier for scabies to be transmitted to other people.
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Prevention

To avoid being infested with scabies from sexual contact, abstaining from sexual contact is the surest way. A mutual monogamous relationship is not an effective way to avoid infestation and latex condoms will provide no protection from infestation of scabies. However, a mutual monogamous relationship and latex condoms will protect against other sexually transmitted diseases (STDs).

People who are infested with scabies and get treated should machine wash any bedding, clothing, towels, etc they had used during the two to three days preceding treatment to kill any scabies left on those items. A hot water cycle (130 degrees F) should be used and a hot dryer cycle should also be used. Items that can not be washed should be dry-cleaned or placed and sealed in a plastic bag for two weeks. Furniture and living areas can be vacuumed to rid them of any scabies. The vacuum bag should be disposed of afterwards.

Those infested people should also tell any sexual partners and household members to check for scabies and get treated.
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