Scabies is a skin infestation caused by a mite known as the Sarcoptes scabiei. Untreated, these microscopic mites can live on your skin for months. They reproduce on the surface of your skin and then burrow into it and lay eggs. This causes an itchy, red rash to form on the skin.
There are approximately 130 million cases of scabies in the world at any given time. While it’s a highly contagious condition that can easily be passed from one person to another through direct skin contact, scabies isn’t a sexually transmitted disease.
The infestation of mites may also be transmitted through infested clothing or bedding. Intimate contact isn’t necessary.
Although scabies can be bothersome, they can usually be eliminated effectively. Treatment often consists of medications that kill scabies mites and their eggs. Since scabies is so contagious, doctors will usually recommend treatment for an entire group of people who are in frequent contact with a person who has scabies.
Recognizing scabies bites and the distinctive red rash can help you find treatment faster.
What does scabies look like?
After the initial exposure to scabies, it can take up to six weeks for symptoms to appear. The symptoms usually develop more quickly in people who’ve had scabies before.
The hallmark symptoms of scabies include a rash and intense itching that gets worse at night. Continuous scratching of the infected area can create sores that become infected. If this occurs, additional treatment with antibiotics for skin infection may be recommended.
Common sites for scabies in older children and adults include the:
- the area between the fingers
Scabies in babies and toddlers, and sometimes the very elderly or immunocompromised, can include the:
- soles of the feet
The rash itself can consist of tiny bites, hives, bumps under the skin, or pimple-like bumps. The burrow tracks of the mite can sometimes be seen on the skin. They may appear as tiny raised or discolored lines.
What causes scabies?
Scabies is the result of an infestation of tiny, eight-legged mites. These bugs are so small you can’t see them on your skin, but you can certainly see their effects.
The mites will burrow into the top layer of your skin to live and feed. Female mites will lay eggs. Your skin will react to the mites and their waste, and you’ll develop a red, itchy rash.
These mites are easily passed between people. Direct skin-to-skin contact is the most common way to share the infestation. The mites can also be spread through infested:
Facilities where people live in close contact with one another often see infestations spread easily. These may include nursing homes or extended-care facilities.
Is scabies contagious?
Scabies is contagious. It can be spread in the following ways:
- prolonged skin-to-skin contact, such as holding hands
- intimate personal contact, such as having sexual intercourse
- sharing clothing, bedding, or towels that have been used by someone with a scabies infection
Since scabies is mostly transmitted through direct physical contact, the infestation can easily be passed on to family members, friends, and sexual partners. The infestation may also spread quickly in:
- nursing homes
- rehab facilities
- sports locker rooms
Types of scabies
There’s only one type of mite that causes a scabies infestation. This mite is called Sarcoptes scabiei. However, these mites can cause several types of infestations.
This infestation is the most common. It causes an itchy rash on the hands, wrists, and other common spots. However, it doesn’t infest the scalp or face.
This type of scabies may develop as itchy, raised bumps or lumps, especially in the genital areas, armpits, or groin.
Some people with scabies may develop another form of scabies known as Norwegian scabies, or crusted scabies. This is a more severe and extremely contagious type of scabies. People with crusted scabies develop thick crusts of skin that contain thousands of mites and eggs.
Crusted scabies can also appear:
- easy to crumble when touched
Crusted scabies usually develops in people with weakened immune systems. This includes people with HIV or AIDS, people who use steroids or certain medications (such as some for rheumatoid arthritis), or people who are undergoing chemotherapy.
The scabies mites can overpower the immune system more easily and multiply at a quicker rate. Crusted scabies spreads in the same way as normal scabies.
The best way to prevent getting scabies is to avoid direct skin-to-skin contact with a person known to have scabies. It’s also best to avoid unwashed clothing or bedding that’s been used by a person infected with scabies.
Scabies mites can live for three to four days after falling off your body, so you’ll want to take certain precautions to prevent another infestation. Make sure to wash all of the following in hot water that reaches 122°F (50°C):
These items should then be dried in the dryer on very high heat for at least 10 to 30 minutes.
Anything that can’t be washed should be thoroughly vacuumed. When you’re finished vacuuming, throw out the vacuum bag and thoroughly clean the vacuum with bleach and hot water.
Bleach and hot water can also be used to clean other surfaces that may contain scabies mites.
Who can get scabies?
Anyone can get scabies. The mites don’t distinguish between sex, race, social class, or income levels. Getting mites also doesn’t have anything to do with your level of personal hygiene or how often you bathe and shower. Skin is skin to a mite looking for a place to burrow.
People who live in close, crowded environments, like college dormitories, may be more likely to get scabies, too. That’s because the infestation is very contagious and can be shared through infested surfaces, like furniture.
The contagious factor is also why toddlers and young children may be more susceptible to scabies. Close contact in a childcare center is a fast way for the infestation to spread.
Older adults are more likely to develop crusted or Norwegian scabies, as are people who have a condition that weakens their immune system.
Your doctor will likely be able to diagnose scabies simply by performing a physical exam and inspecting the affected area of skin. In some cases, your doctor may want to confirm the diagnosis by removing a mite from the skin with a needle.
If a mite can’t easily be found, your doctor will scrape off a small section of skin to obtain a tissue sample. This sample will then be examined under a microscope to confirm the presence of scabies mites or their eggs.
A scabies ink test (or Burrow Ink Test) can help spot burrowed paths in your skin created by the mites. To do this test, your doctor can drop ink from a fountain pen onto an area of the skin that appears to be infested. They then wipe away the ink.
Any ink that fell into the burrowed tunnels will remain and be obvious to the naked eye. That’s a good indication you have an infestation.
How long does scabies last?
Scabies mites can live on a person for up to two months.
Once they’re off a person, however, the mites typically die within three to four days.
If you’re treating scabies, you can expect that the itching and burning caused by the rash will last for several weeks after treatment begins. That’s because the eggs and mite waste are still in your skin, even if the mites are dead.
Until your skin grows new layers, you may still have a rash and irritation.
Human scabies is caused by an infestation of the skin by the human itch mite (Sarcoptes scabiei var. hominis). The microscopic scabies mite burrows into the upper layer of the skin where it lives and lays its eggs. The most common symptoms of scabies are intense itching and a pimple-like skin rash. The scabies mite usually is spread by direct, prolonged, skin-to-skin contact with a person who has scabies.
Scabies occurs worldwide and affects people of all races and social classes. Scabies can spread rapidly under crowded conditions where close body contact is frequent. Institutions such as nursing homes, extended-care facilities, and prisons are often sites of scabies outbreaks.