THURSDAY, Feb. 16, 2023 (HealthDay News) -- Talk about the stuff of nightmares. You have extremely itchy skin at bedtime, not to mention a pimple-like rash. What is it?

Those are fairly clear signs of scabies, a microscopic parasitic infestation where mites burrow under your skin and lay eggs there.

Scabies infection comes from prolonged contact, not just a quick brush against someone else’s skin. It can also be passed through bedding or clothing.

“Anyone who is diagnosed with scabies, as well as his or her sexual partners and other contacts who have had prolonged skin-to-skin contact with the infested person, should be treated,” the U.S. Centers for Disease Control and Prevention advises.

What is scabies?

This “human itch mite” lives and lays eggs in the upper layer of the skin, according to the CDC.

About 200 million people worldwide have scabies at any one time, including up to 10% of children in poor areas, according to the World Health Organization.

Once the eggs hatch, the larvae can travel to the skin’s surface, spreading to other areas or other people, according to the Mayo Clinic.

What does scabies look like? It may resemble hives, tiny bites, knots under the skin or even eczema-like scaly patches, according to the American Academy of Dermatology (AAD). Sores may develop from scratching.

Under magnification, the mite is creamy-white, has eight legs and a round body. It is roughly the size of a needle tip, according to the Cleveland Clinic.

How to identify scabies

A doctor can best do this, but signs can include the rash and intense itching that worsens at night.

Mites are most commonly found between the fingers, around the fingernails, on elbows, wrists, at the belt line, in the genital area and around the nipples, according to the AAD.

Sometimes children will have an all-over rash, including their scalp. Infants typically have it on the palms and soles, according to the AAD.

Although scabies is contagious, children can typically return to school the day after treatment, according to an article recently published by HealthDay.

A severe form called crusted scabies, or Norwegian scabies, leads to widespread crusts on skin with hundreds or thousands of mites, instead of 15 or 20. It can impact someone with a weakened immune system, according to the AAD.

How do you get scabies?

Scabies is commonly spread between sexual partners or among members of the same household.

Crowded conditions can also contribute, according to the CDC. Outbreaks are common in nursing homes, prisons and child care facilities.

What causes scabies? It’s a mite known as Sarcoptes scabiei var hominis.

Incubation time ranges from just one to four days if you’ve had scabies before to four to eight weeks, the CDC said.

Scabies symptoms

Scabies cause an “intense, unbearable itch,” according to a report published recently in the journal Frontiers in Medicine. This is caused directly by the mites and the body’s immune response to them.

A later rash can look like lines on the skin that are grayish or skin-colored, according to the Cleveland Clinic.

Scratching too much can cause a skin infection, such as impetigo, according to Mayo Clinic. Untreated scabies can even lead to complications such as chronic kidney disease, according to the Frontiers in Medicine report.

Scabies treatment

Scabies medications include creams and pills, according to the Mayo Clinic. The condition won’t resolve without treatment.

What is a good treatment for scabies? Apply a prescription cream that contains permethrin to clean skin on the entire body, including palms and soles of the feet. Children may also need it on the scalp.

Leave the cream on for eight to 14 hours before washing it off, the Cleveland Clinic advised.

The veterinary drug ivermectin, which gained fame during the pandemic as a failed treatment for COVID-19, can be used in small doses to treat parasites, according to a recent HealthDay story.

Just last summer, health officials in the Solomon Islands initiated a mass rollout of ivermectin to treat an outbreak of scabies among children there.

“Scabies affects everyone, especially young children,” Sarah Andersson, program manager of the rollout, said in a Murdoch Children's Research Institute news release. "Rolling out the treatment for scabies to all communities in the Solomon Islands at the same time will contribute significantly to stopping the spread of scabies and preventing this debilitating condition.”

Ivermectin is given in two doses separated by a week or two under a doctor's guidance. It shouldn’t be used by someone who is pregnant or lactating or in children weighing less than 35 pounds, according to the Cleveland Clinic.

Bumps and itching may persist for up to four weeks even though the mites are dead. Antihistamines can help with the itching, the Cleveland Clinic noted. Anyone who has had close contact with a person infected with scabies should also be treated.

Wash clothing and bedding in hot water followed by a hot dryer. Vacuum carpets and furniture well, especially if someone has had crusted scabies, the CDC recommends.