What scabies look like?

Scabies – including symptoms, treatment and prevention

Scabies is an infestation of the skin caused by the scabies mite Sarcoptes scabiei (see image). The mite is very tiny, 0.2 mm to 0.4 mm long, and cannot easily be seen without magnification. It occurs worldwide and in all races and social classes. Scabies is not an indication of poor hygiene.

How scabies is spread

Scabies is usually transmitted by direct skin-to-skin contact, or rarely, by underwear or bed clothes that have been freshly contaminated by an infested person. The mites can survive for only a few days off the human or animal body.

Signs and symptoms

Scabies and other mites usually infest the skin especially where there are creases, such as:

  • between the fingers (see images)
  • on the front of the wrists
  • in the folds of the elbows, armpits and buttocks
  • genitals.

When mites have been transmitted from animals (such as dogs) to people, the mites are commonly found on areas of skin having contact with the animal, including forearms, chest and neck. However, mites from animals cannot breed on humans, so do not cause ongoing infestation. Scabies mites cause intense itching, especially at night. Thread-like ‘tunnels’, about 10 mm long, may be visible as grey lines in the skin, but they are often difficult to detect. Scabies infection may appear on the genitals as small itchy lumps.

Image courtesy Public Health Image Library (PHIL), Department of Health and Human Services, Centers for Disease Control and Prevention (CDC-USA)

Diagnosis

Scabies and other mites that cause skin disease are diagnosed by examining skin scrapings with a microscope.

Incubation period

(time between becoming infected and developing symptoms)

Itching begins 2 to 6 weeks after infestation in individuals not previously exposed to scabies and within 1 to 5 days in individuals previously exposed.

Infectious period

(time during which an infested person can transmit the infestation to others)

Until the mites and eggs are destroyed by treatment. People can be infectious even before the itching begins.

Treatment

Skin disease caused by mites can easily be confused with other skin diseases. Treatment should not be undertaken until the diagnosis has been confirmed by a doctor, following examination of skin scrapings for mites. This is particularly important for babies, pregnant women or people who already have other forms of skin disease. Babies under 12 months of age need special treatment. Treatment involves application of insecticidal cream, lotion or solution as prescribed by a doctor. For see the Direction for the application of a topical scabicide (PDF 59KB) for detailed information on what you should do and how to apply topical scabicides.

Prevention

  • Exclude people with scabies from childcare, preschool, school and work until one day after treatment commences.
  • All close (skin-to-skin) contacts and other people in the same household should be treated at the same time, even if no itching or other symptoms are present. By the time scabies is diagnosed in one person, many other people may have been infested. If everyone is not treated at the same time, treatment is likely to be unsuccessful.
  • Underwear, clothing, towels, bed linen and personal effects such as slippers, bed jackets, dressing gowns and knee rugs used by the affected person in the 72 hours prior to treatment should be laundered using a hot wash cycle (hotter than 50°C) or hot tumble dried to kill the mites. If items are unable to be laundered or hot tumble dried, place them in a sealed plastic bag and leave them for 72 hours before airing and reusing.
  • Mattresses and upholstered furniture can be vacuumed or gently ironed.

Useful links

  • Scabies management in care facilities

  • Exclusion periods from childcare, preschool, school and work

Image 2 and 3 – Scabies (Sarcoptes scabiei var. hominis). Image courtesy of Public Health Image Library (PHIL), Department of Health and Human Services, Centers for Disease Control and Prevention (CDC-USA)

Scabies

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What Is Scabies?

Scabies is a common skin problem caused by tiny mites called Sarcoptes scabiei. The mites burrow into the skin, leave their feces (poop). The female mites lay eggs in the tiny tunnels they create. This causes small itchy bumps and blisters. The itching and rash from scabies are due to a hypersensitive reaction to the mite, its feces, and its eggs.

What Are the Signs & Symptoms of Scabies?

The most common symptom of scabies is itching, which usually starts before any other signs. Other symptoms of scabies include:

  • bumps or blisters
  • burrow tracks
  • thickened, scaly, scratched, and scabbed skin
  • in young children, irritability and poor feeding

Scabies can show up on any part of the body but is most common on:

  • the hands and feet (especially the webs of skin between the fingers and toes)
  • the inner part of the wrists and the folds under the arms
  • waistline and groin area
  • head and scalp of infants (rare in older children and adults)

It usually takes about 3 weeks after infection for symptoms to show in someone who’s never had scabies. People who have had scabies before might see symptoms in a few days.

Is Scabies Contagious?

Scabies is contagious. It spreads through close contact with someone who is infected. Direct physical contact — like holding hands — is the most common way people get scabies.

Mites can live for about 2–3 days in clothing, bedding, or dust. So people can get scabies by sharing clothing, towels, or bedding used by someone who has scabies.

Scabies spreads most easily in crowded places with a lot of close contact, such as childcare centers, college dorms, and nursing homes.

How Is Scabies Diagnosed?

Doctors usually diagnose scabies based on symptoms and how the rash looks. The doctor may scrape the skin to look for mites or eggs under a microscope.

How Is Scabies Treated?

Doctors treat scabies by prescribing a medicated cream or lotion to kill the mites. Apply the cream to skin all over the body (from the neck down), not just the area with the rash. In infants and young children, also put the cream on the face (avoiding the mouth and eyes), scalp, and ears. Trim your child’s nails and also put medicine on the fingertips.

Most treatments need to stay on the skin for 8–12 hours before they’re washed off. You may want to apply the medicine before your child goes to bed, then wash it off in the morning.

If treatment is effective, there should be no new rashes or burrows after 24–48 hours. The treatment may need to be repeated in 1–2 weeks. It may take 2–6 weeks after successful treatment before the itching and rash are gone.

Sometimes doctors use an oral (taken by mouth) medicine instead of skin lotion to treat scabies in older children.

The doctor might recommend an antihistamine or steroid cream, like hydrocortisone, to help with itching.

Can Scabies Be Prevented?

Household members and close contacts of someone being treated for scabies should get treated at the same time, even if they have no symptoms. This will help prevent the spread of scabies.

Wash clothing, sheets, and towels in hot water and dry on a hot setting. Put stuffed animals and any other items you can’t wash in a sealed plastic bag for at least 3 days. Vacuum each room in the house, then throw away the vacuum cleaner bag.

What Else Should I Know?

Most kids can return to school the day after treatment is complete.

Scratching the itchy areas of skin can let bacteria get into the skin. The doctor will prescribe antibiotics if your child gets a skin infection. Talk to your doctor if you notice any signs of skin infection, such as redness, swelling, or pus.

Reviewed by: Mary L. Gavin, MD Date reviewed: October 2019

In This Section

  • Scabies
  • What are the symptoms of scabies?
  • Do I have scabies?
  • How do I treat scabies?
  • How can I prevent getting or spreading scabies?

Common symptoms of scabies include intense itching that’s often worse at night. You may also have a rash, pimple-like bumps, and small, curling lines on your skin.

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Scabies symptoms

The symptoms of scabies aren’t always easy to see, or they may seem like something else (like a rash from allergies).

Signs of scabies are:

  • Intense itching that gets worse at night.

  • Rashes that have pimple-like bumps, tiny blisters, or scales.

  • Small, raised, crooked lines on your skin (caused by the scabies mites burrowing under the surface of your skin).

Places where people usually get a scabies rash include:

  • the webbing between your fingers

  • where your wrist, elbow, or knee bends

  • pubic and groin areas

  • breasts

  • belly button

  • penis and scrotum

  • thighs and the lower part of your butt

  • shoulder blades

  • around your waist

Symptoms may come and go, but that doesn’t mean the scabies infection went away. The only way to get rid of scabies is to get treated. You can spread scabies to other people whether or not you have symptoms, so it’s important to visit a doctor or nurse if you think you might have scabies.

When does the scabies skin rash usually develop?

If you’ve never had scabies before, it can take up to 3-6 weeks after you get scabies for the symptoms to start. But if you’ve had scabies before and get it again, the symptoms can start within a few days.

You can spread scabies to other people as soon as you get it — even before you have symptoms.

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What is scabies?

Scabies is an itchy skin condition caused by tiny parasites. It’s passed through skin-to-skin contact, usually during sex. Scabies isn’t dangerous and can be cured.

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Scabies is a skin condition

Scabies (pronounced skay-bees) is caused by scabies mites — tiny, insect-like parasites that infect the top layer of your skin. Scabies causes rashes, irritation, and a ton of itching. It’s easily spread to other people during skin-to-skin touching.

Scabies mites burrow underneath the top layer of your skin and lay eggs. The eggs lead to more mites, but most people with scabies only have about 10-15 mites on their body at a time. The mites are super small so you might not see them, but you’ll probably notice the itching and irritation they cause.

Scabies can be really uncomfortable, but it’s usually not dangerous. It can be cured with medicated creams or pills.

How is scabies contracted?

Scabies is spread by direct skin-to-skin touching. This usually happens during sex, especially when your bodies are touching or close for a long time (like if you sleep in a bed together).

Most adults get scabies from sex, but you can get it other ways, too. Scabies can be spread to other people in your home, and it’s common in crowded places that may have lots of close skin contact (like nursing homes, prisons, and child care places). You can sometimes get scabies from sharing an infected person’s clothes, towels, or bedding.

It’s very hard to get scabies from quick, casual touching, like handshakes or hugs. You also can’t usually get scabies from toilet seats. Most of the time, it takes lots of close, personal contact with an infected person for scabies to spread.

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Biology

Causal Agent:

Sarcoptes scabiei var. hominis, the human itch mite, is in the arthropod class Arachnida, subclass Acari, family Sarcoptidae. The mites burrow into the upper layer of the skin but never below the stratum corneum. The burrows appear as tiny raised serpentine lines that are grayish or skin-colored and can be a centimeter or more in length. Other races of scabies mites may cause infestations in other mammals, such as domestic cats, dogs, pigs, and horses. It should be noted that races of mites found on other animals may cause a self-limited infestation in humans with temporary itching due to dermatitis; however they do not multiply on the human host.

Life Cycle:

Sarcoptes scabiei undergoes four stages in its life cycle: egg, larva, nymph and adult. Females deposit 2-3 eggs per day as they burrow under the skin . Eggs are oval and 0.10 to 0.15 mm in length and hatch in 3 to 4 days. After the eggs hatch, the larvae migrate to the skin surface and burrow into the intact stratum corneum to construct almost invisible, short burrows called molting pouches. The larval stage, which emerges from the eggs, has only 3 pairs of legs and lasts about 3 to 4 days. After the larvae molt, the resulting nymphs have 4 pairs of legs . This form molts into slightly larger nymphs before molting into adults. Larvae and nymphs may often be found in molting pouches or in hair follicles and look similar to adults, only smaller. Adults are round, sac-like eyeless mites. Females are 0.30 to 0.45 mm long and 0.25 to 0.35 mm wide, and males are slightly more than half that size. Mating occurs after the active male penetrates the molting pouch of the adult female . Mating takes place only once and leaves the female fertile for the rest of her life. Impregnated females leave their molting pouches and wander on the surface of the skin until they find a suitable site for a permanent burrow. While on the skin’s surface, mites hold onto the skin using sucker-like pulvilli attached to the two most anterior pairs of legs. When the impregnated female mite finds a suitable location, it begins to make its characteristic serpentine burrow, laying eggs in the process. After the impregnated female burrows into the skin, she remains there and continues to lengthen her burrow and lay eggs for the rest of her life (1-2 months). Under the most favorable of conditions, about 10% of her eggs eventually give rise to adult mites. Males are rarely seen; they make temporary shallow pits in the skin to feed until they locate a female’s burrow and mate.

Transmission occurs primarily by the transfer of the impregnated females during person-to-person, skin-to-skin contact. Occasionally transmission may occur via fomites (e.g., bedding or clothing). Human scabies mites often are found between the fingers and on the wrists.

Life cycle image and information courtesy of DPDx.

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