Scabies occurs when human itch mites bite and burrow into the skin, laying eggs. The symptoms include intense, uncomfortable itching and a rash.
A person cannot treat scabies with over-the-counter products. They will need prescription medication to treat the infection and prevent it from spreading to others.
This article will help a person identify whether their skin lesions could be due to scabies and how they can treat it.
A scabies rash is extremely itchy. Typically, the itching will be worse at night. People who are unsure whether scabies is the cause of their symptoms can consider the following factors:
- Appearance: Scabies bites cause a rash that often presents as small blisters, which doctors call vesicles. Some people may think that it resembles pimples. Itching the vesicles can cause them to turn into open skin sores, making a person more vulnerable to infection.
- Pattern: Scabies mites tend to burrow or tunnel under the skin, which can create a distinct pattern. The pattern consists of lines that are flesh-toned or, sometimes, gray and white. In some cases, the tunnels may be very hard to see.
- Location in adults: The most common scabies sites in adults include the buttocks, elbows, waist, wrists, and skin between the fingers. Sometimes, a person may find mite burrows under a ring, watchband, or fingernail.
- Location in children: The most common scabies bite locations in infants and children are the face, neck, palms of the hands, and soles of the feet.
- Timing: According to the American Academy of Dermatology, if a person has not had a scabies infection before, their symptoms may not appear until about 2–6 weeks after the initial infestation. However, if a person has had scabies before, they will usually develop symptoms within 1–4 days.
In some instances, scabies bites may crust over. Once crusted, scabies may not itch. However, crusting could indicate a significant and highly contagious infection.
Several rashes and bites may closely resemble scabies. These include the following:
- Atopic dermatitis: Also known as eczema, this condition causes dry, itchy patches.
- Contact dermatitis: This allergic reaction to a chemical or another irritant can cause an itchy rash.
- Folliculitis: This condition occurs when hair follicles become inflamed, often due to a bacterial infection. It typically presents as papules or pustules.
- Insect bites: Bites from other insects, such as bed bugs, chiggers, fleas, mites, and mosquitoes, can cause itching.
- Papular urticaria: This condition is an allergic reaction to insect bites. It causes bumps that may appear similar to scabies.
A doctor will consider all of a person’s symptoms when making a diagnosis.
A doctor will typically prescribe a topical treatment called permethrin (Elimite) cream to treat scabies. A person must apply this cream to all skin surfaces, not just where the rash appears. Usually, they will apply the cream at night before bed.
Key areas to which people should apply the cream include:
- between the fingers and toes
- in the bellybutton
- on the buttocks
- on the waistline
The immediate side effects of the cream include a mild burning, itching, or stinging sensation. When a person wakes up, they can shower to remove the permethrin cream, if they wish.
A person should also keep their nails short and trimmed, as this keeps the mites from hiding under the fingernails.
One application of permethrin cream will cure an estimated 95% of scabies infestations. A person may continue to itch or see a rash after the application, but this does not necessarily mean that the scabies is not cured.
Doctors will usually advise a person to apply permethrin cream every week until they are sure that the scabies has gone.
In rare instances, a doctor may prescribe an oral medication called ivermectin (Stromectol) to treat scabies. This treatment is newer than permethrin cream, which is a more traditional and often less expensive treatment option.
In addition to killing scabies with permethrin cream, people can take steps to reduce the itching at home. Examples include:
- taking medications, such as antihistamines or oral steroids, to reduce itching
- applying topical corticosteroid or antihistamine creams to reduce itching
- soaking in a tub of warm (not hot) water and using a soft washcloth to scrub the itchy areas, which can help remove dead mite material
While scabies usually spreads via skin-to-skin contact, its transmission is possible through contact with clothing or linens.
In addition to applying topical treatments to the skin, it is important that people take steps to clean their home and soft materials to prevent reinfestation or the transmission of the condition to another person.
Ways to accomplish this include washing any clothing, linens, and towels that people with scabies have worn or used within the past 3 days. The mites cannot survive washing at any temperature.
Most mites cannot live beyond 3–4 days without being on a human host.
A scabies infection is the result of a bite from Sarcoptes scabiei var. hominis. These mites are microscopic, so a person cannot see them.
Scabies spreads through close and sometimes intimate contact. Examples include:
- in facilities where people are often in close contact, such as child care centers, nursing homes, and prisons
- sexual contact
- sharing bedding, clothing, or towels with someone who has the infection
- sleeping on sheets that have mites on them
Any time a person has direct, close, and sometimes prolonged contact with a person who has scabies, they are at risk of getting it.
However, a person does not usually get scabies from short interpersonal interactions, such as a brief handshake or hug.
A person should see their doctor if they experience the following symptoms:
- itchy areas of skin
- vesicles that appear on the skin
- discolored areas of irritated skin that do not go away
A doctor can often diagnose scabies by visually inspecting the rash and noting any accompanying symptoms. If a doctor still needs to confirm that the rash is scabies, they can perform skin scraping to get a sample for analysis under a microscope.
Scabies infections can be bothersome and contagious. Treating them as soon as symptoms appear can relieve itching and discomfort.
If a person suspects that they have scabies, they should see a doctor or dermatologist as soon as possible.