Scabies Slideshow: Symptoms, Cause, and Treatments

Scabies is not an infection, but an infestation. Tiny mites called Sarcoptes scabiei set up shop in the outer layers of human skin. The skin does not take kindly to the invasion. As the mites burrow and lay eggs inside the skin, the infestation leads to relentless itching and an angry rash.

When a person is infested with scabies for the first time, it can take four to six weeks for the skin to react. The most common symptoms are:

• Intense itching, especially at night
• A pimple-like rash
• Scales or blisters
• Sores caused by scratching

In its early stages, scabies may be mistaken for other skin conditions because the rash looks similar. This image compares acne, mosquito bites, and scabies. What sets scabies apart is the relentless itch. Itching is usually most severe in children and the elderly.

Another hallmark of scabies is the appearance of track-like burrows in the skin. These raised lines are usually grayish-white or skin-colored. They are created when female mites tunnel just under the surface of the skin. After creating a burrow, each female lays 10 to 25 eggs inside.

Scabies mites can live anywhere on the body, but some of their favorite spots include:

• Between the fingers
• The folds of the wrist, elbow, or knee
• Around the waistline and navel
• On the breasts or genitals
• The head, neck, face, palms, and soles in very young children

Most people with scabies only carry 10 to 15 mites at any given time, and each mite is less than half a millimeter long. This makes them very difficult to spot. To the naked eye, they may look like tiny black dots on the skin. A microscope can identify mites, eggs, or fecal matter from a skin scraping.

Scabies typically spreads through prolonged, skin-to-skin contact that gives the mites time to crawl from one person to another. Shared personal items, such as bedding or towels, may occasionally be to blame. Scabies can be passed easily between family members or sexual partners. It is not likely to spread through a quick handshake or hug. The scabies mite can’t jump or fly, and it crawls very slowly.

Dogs and cats get scabies, too -- better known as mange. However, canine scabies and feline scabies are not caused by the same type of mite that triggers human scabies. You can get mites from handling an infested pet, but these mites can’t reproduce in human skin. This means they usually die off without causing serious symptoms.

Anyone can get scabies, but those at higher risk include:

• Sexually active adults
• Prison inmates
• People in institutional care
• People living in crowded conditions
• People in child care facilities

Scabies outbreaks occasionally strike daycare centers. Young children tend to play in ways that involve skin-to-skin contact. They may also share naptime mats and blankets. If scabies is found in a child who attends daycare, it’s important to notify the staff. The child's classmates and caregivers will probably need to be treated as well, even if symptoms have yet to appear.

Long-term care facilities, including nursing homes and homes for the developmentally disabled, are also prone to scabies outbreaks. Because caregivers assist residents with bathing and dressing, skin-to-skin contact is common. The CDC recommends all new long-term care patients and staff be screened for scabies.

Also called Norwegian scabies, crusted scabies is a very severe infestation involving tens of thousands of mites on a single person. This causes the skin to develop thick crusts full of mites and eggs. Crusted scabies is most common in people with weakened immune systems, the elderly, and people who are disabled. This type of scabies is highly contagious and requires swift treatment to prevent outbreaks.

The intense itch of scabies makes it difficult to resist scratching. Frequent scratching can create open sores that are prone to infection. Bacterial skin infections, such as impetigo, are the most common complication of scabies. Symptoms may include honey-colored, oozing blisters. This type of infection is usually treated with antibiotics.

In most cases, a doctor can identify scabies based on the appearance of the rash and your description of the itch. Sometimes a skin scraping is used to confirm the diagnosis. This involves collecting skin from the affected area and using a microscope to check the sample for mites, eggs, or fecal matter.

Scabies will not go away on its own. It can only be cured with prescription medications that kill the mites. Treatment is a cream or lotion that is applied to the entire body from the neck down in most cases. It is left on for 8 to 14 hours and then washed off. In some cases, a doctor may prescribe pills to treat scabies. Treatment takes up to three days, depending on the medication used.

While prescriptions can kill scabies mites and their eggs, they don't provide any immediate itch relief. To control itching, especially at night, antihistamine pills can help. Hydrocortisone cream may also help, but it can change the appearance of the scabies rash, making the condition harder to diagnose. It's best to use this cream only after your doctor has confirmed the diagnosis.

When someone is diagnosed with scabies, anyone who has close physical contact with the person should also be treated. Close contact includes bathing together, sleeping in the same bed, or even holding hands. Doctors usually recommend treating all members of the household, even if symptoms are not present. (Remember, it can take four to six weeks for symptoms to appear.)

Scabies mites can live up to two to three days on the surface of clothes, bedding, or towels. To make sure these mites are killed, wash any sheets and clothing used by the affected person within the past three days. Wash the items in hot water and dry them in a hot dryer or take them to a dry-cleaner. Items that can't be washed should be placed in a sealed plastic bag for seven days.

Scabies medications can kill the mites and eggs quickly, and patients can usually return to school or work 24 hours after starting treatment. However, the itch may persist for a few weeks. This is the result of an ongoing allergic reaction in the skin. If the itching continues for more than four weeks or a new rash appears, see your doctor. It may be necessary to reapply scabies medication.