What Is Scabies? Symptoms, Causes, Diagnosis, Treatment, and Prevention

Scabies is caused by the human itch mite (Sarcoptes scabiei), a tiny, eight-legged parasite that burrows into the upper layer of the skin in order to feed and live. Female mites also lay eggs there. (1) When this happens, the skin often breaks out into an itchy, pimple-like rash in an allergic reaction to the mites, their eggs, and their waste. (2)

Though scabies is pretty unpleasant to think about, the good news is that it’s very treatable. Scabies treatment involves topical remedies and, depending on the severity of the infestation, oral medication. All these medications are currently available only by prescription, so it’s vital to see your healthcare provider in order to solve the problem.

Once treatment is started and the mites are eliminated, the itching and scabies rash symptoms should resolve within a few weeks. (1)

Scabies typically causes intense itching, which can be worse at night and potentially so persistent that it keeps you from sleeping. This itching is the earliest and most common symptom of scabies. (3)

Scabies can occur anywhere on the body, but the mites tend to prefer certain areas, including: the hands (especially the skin between the fingers and around the nails), armpits, elbows, wrists, and areas of skin that are usually covered by clothing, such as shoulder blades, the groin area, breasts, the area around the beltline, and the buttocks. Skin that’s covered by jewelry, such as watches, bracelets, or rings, is also often affected. (4)

In young children and infants, itching and rash may affect the head, face, neck, palms, and the soles of the feet, but this typically doesn’t occur in adults and older kids. (1) Scabies rashes in infants and young children might appear redder or include larger blisters. (5)

What Does Scabies Look Like?

Not everyone infested with mites has a scabies rash, but many people do. The rash consists of small, red bumps that may look similar to pimples or small insect bites, and the bumps are often in a line. These aren’t “scabies bites” so much as an allergic reaction the skin has to the presence of the mites. This reaction can also resemble other rashes, but your doctor or dermatologist can determine whether it’s scabies. Some people infested with the mites have scaly patches that look like eczema. (4)

You may also notice tiny, snaking, raised lines — about a centimeter long — that are caused by the female scabies mites burrowing under the skin. These burrows are grayish-white or skin-colored, and while they can be difficult to find, they tend to appear in the webbing between fingers; in the folds of the wrist, knee, or elbow; and in the groin area, breasts, and shoulder blades. (3)

In someone who’s never had scabies, it can take as long as four to six weeks before symptoms begin to appear, although symptoms typically develop three to four weeks after you’ve had contact with a mite. It’s important to be aware that a person is capable of spreading mites during this period even when they show no signs of scabies. Without medical treatment, the condition persists because the mites lay eggs, causing continued infestation. (1)

Symptoms in people who have had previous scabies infestations tend to show up much more quickly, within one to four days.

Learn More About the Signs and Symptoms of Scabies

What Is Crusted Scabies, and How Is It Different?

Crusted scabies, also known as Norwegian scabies, is a severe form of infestation found almost exclusively in those with severely weakened immune systems. It’s much less common than regular scabies, but more contagious. Most people who get scabies have about 10 to 15 mites in their skin. Crusted scabies is an infestation with an extremely large number of mites — sometimes up to two million, according to the Centers for Disease Control and Prevention (CDC). (3)

It affects people whose bodies can’t develop resistance to the mites, and the mites multiply quickly. This includes people who have a weakened immune system, such as people with HIV or chronic leukemia, as well as elderly people. (1,6)

People with crusted scabies may not experience the typical scabies rash or itch so intensely, but they’re highly contagious to other people. Thick, grayish crusts develop that tend to crumble easily when touched. These are especially common on folds of the skin, such as in the armpit, groin, and finger-web spaces. (4) But these crusts, filled with mites, can also fall off. The mites can live inside the crust for up to a week without human contact, which is part of what makes crusted scabies so contagious in certain environments. (4,7)

Scabies is contagious, and it’s usually spread by having direct, prolonged skin-to-skin contact with an affected person. (2) The exposure generally has to be sustained: A handshake or hug typically doesn’t spread the mites, but holding hands for 5 or 10 minutes can. (The exception is crusted scabies, where an infested person can transmit the mites even with very brief contact.) In adults, scabies is often spread through sexual encounters. (1) And it’s easily spread within households.

While the mites live for one to two months on human skin, they can survive for up to four days on inanimate objects such as bedsheets, clothing, and towels. Less commonly, scabies can occur through contact with an infested item. This kind of indirect infection more frequently occurs in people who have crusted scabies. (1)

Scabies are not spread to people from pets. Pets can become infested with animal mites, and these can be passed along to humans. But animal mites can’t reproduce on a person, and even if they get under a person’s skin, they’ll die within a couple of days. (1) It’s important to treat your pets, though, if they acquire mites.

Getting scabies from swimming in a pool is extremely unlikely. In most cases of scabies, excluding crusted scabies, an infested person has only 10 to 15 mites on their body, and the chances that a mite would emerge from beneath wet skin are very low. (1) Still, although it is uncommon, you could contract scabies by sharing a towel with an infested person.

If you suspect you have scabies, you must get checked out by a healthcare provider in order to treat the condition properly and avoid spreading it. A doctor will perform a visual exam to look for the scabies rash on your body and for burrows. Reactions to certain drugs can mimic a scabies rash, (1) and other conditions can produce skin reactions that look similar. To be sure it’s scabies, your doctor may want to confirm the presence of a mite, its eggs, or its fecal matter. This can be done by taking a scraping of skin to examine under a microscope or by using a needle to extract a mite from its burrow. (8)

Prognosis of Scabies

With proper treatment that kills the mites, scabies goes away. Still, it’s a contagious infection and can be contracted again.

Scabies subsides once the mites have been killed. Once treatment starts, this typically takes a week. After treatment, even if all the mites have been eradicated, you may have residual itching for up to a few weeks. If the itching lasts more than two to four weeks, or if you notice new burrows or the pimple-like scabies rash, you might need retreatment.

Successful treatment of scabies means eradicating the mites. This involves using a medication known as a scabicide. While some over-the-counter creams and products can help reduce or alleviate symptoms like itching, they won’t kill mites. Scabicides are currently only available by prescription. (1)

Medication Options

For common, noncrusted scabies, patients may be prescribed a topical medication.

Permethrin (Elimite) cream is the most commonly prescribed. Crotamiton (Eurax) cream, sulfur ointment, or lindane lotion may also be considered, depending on the needs of the patient. (9) These are applied to the entire body, from the neck down, on clean, dry skin and left on for about 8 to 14 hours before being washed off. (10) You usually need to repeat this process a week after the first treatment to get rid of any newly hatched mites.

Treatment of crusted scabies calls for an oral antiparasitic medicine, ivermectin (Stromectol), along with topical medication. Depending on the severity of the infestation, these pills are taken in three, five, or up to seven doses. (9)

In conjunction with a scabicide, your doctor may prescribe an antihistamine or steroid cream to help reduce itching and inflammation of the skin. (11)

Adults can usually go back to work and children to school the day after treatment. (12)

Alternative and Complementary Therapies

Researchers have been looking into the effectiveness of essential oils as an alternative in treating scabies. A 2020 study that involved scabies in rabbits concluded that lemongrass oil — which is reported to have antiparasitic, antioxidant, antimicrobial and anti-inflammatory properties — should be considered a promising treatment. (13)

Tea tree oil, which has antibacterial, anti-inflammatory, and anti-itching effects, has also been examined as a possible remedy for scabies. In a review of studies published in 2016, the authors called for more research into the topic, noting a growing resistance to current standard treatments like ivermectin and permethrin. (14)

Learn More About Treatment for Scabies: Medication, Alternative and Complementary Therapies, and More

Prevention of Scabies

Experimental research is underway to develop a vaccine to prevent scabies, though it would likely take years before it would be available. (15) There is currently no surefire way to avoid getting scabies, other than to avoid close contact with an infested person and certain items they’ve used, such as clothing, bedding, and towels.

To ensure successful treatment and reduce the chance of re-exposure, bedding, clothing, and towels used by a person with scabies or anyone they came in close contact with must be washed in hot water and dried with high heat. You can also dry-clean these items or seal them in a plastic bag for at least 72 hours to kill any mites that may still be around. (10) When you start treatment, vacuum your home, too. (11)

When someone has scabies, their sexual partners and any members of their household need to get treated as well — and at the same time — so that reinfestation doesn’t occur. (10) Since human itch mites don’t survive on animals, your pet doesn’t need to be treated. (11)

If you’re sexually active, wait to have sex until you and your partner have both finished treatment. While condoms can prevent other sexually transmitted infections, they’re not an effective barrier when it comes to the skin-to-skin contact through which scabies spreads. (16)

A scabies infestation can lead to complications when secondary infections develop. The nonstop scratching can result in open sores that can get infected with bacteria, often staph (Staphylococci) or sometimes strep (Streptococci), causing another skin infection called impetigo. (6) While impetigo usually isn’t dangerous, if it’s not controlled with antibiotics, it can lead to serious complications. If bacteria enters the bloodstream, it can result in life-threatening sepsis. Inflammation of the kidneys can also be caused by the same bacteria as impetigo. (3,17)

According to the World Health Organization (WHO), an estimated 200 million people are affected by scabies at any given time. (18) Infections happen in all parts of the world, though the WHO notes that the highest rates of scabies and scabies-related secondary infections occur in hot, tropical climates, especially in overcrowded communities.

But scabies can happen to anyone, regardless of geographic location, socioeconomic status, race, gender, or age. Some people, though, are particularly susceptible to scabies. This includes children, mothers of young children, sexually active young adults, elderly people who live in nursing homes, and hospital patients. (7) People whose immune systems are compromised and people who have had organ transplants are also at greater risk.

Scabies outbreaks affect residents of facilities such as nursing homes and rehabilitation centers, dormitories, and prisons — basically any institutional setting where close body contact is frequent. (1) Environments such as childcare centers and camps are also at risk for outbreaks. (5)