Scabies Symptoms, Diagnosis and Treatment

How This Infestation with Microscopic Mites is Diagnosed and Treated

Girl (1-3) standing living room, scratching elbow
Getty Images/Gary Houlder

Scabies is a skin infection caused by an infestation with the microscopic Sarcoptes scabei parasitic mite. The mites are very tiny, they can't usually be seen with the naked eye. Scabies can be diagnosed under the microscope by your doctor. Although distressing for parents, who associate conditions like scabies and head lice with poor hygiene, scabies is fairly common and affects children of all races and social classes.


Symptoms of Scabies

After being exposed to someone with scabies, it can take 4-6 weeks for a rash to develop, which appears as:

  • Little red bumps, nodules, or pimple-like irritations, which are most commonly located on the webbing between children's fingers, on the inner part of their wrist, under their arms, and on their elbows, knees, and along their belt line.
  • Short zigzag or S-shaped lines or burrows
  • Sores, which can be caused by a secondary bacterial infection

In addition to the rash, the most characteristic symptom of scabies is that the rash is intensely itchy, especially at night.

Diagnosis of Scabies

Although the rash that scabies induces is easy to see, the actual scabies mite is very tiny and can usually only be seen with a microscope. If necessary, your doctor might place a drop of mineral oil on a burrow, take a scraping, and look at it under a microscope to look for the scabies mites or their eggs.

This requires an intact burrow, though, that hasn't been scratched, so can't always be done. And most kids don't appreciate your scraping their skin with a scalpel anyway. Fortunately, it isn't always necessary, as most doctors can diagnosis scabies by the pattern of symptoms described above.

An ink test is also sometimes done.

This involves placing ink on what you think is a burrow, wiping it away, and then seeing if some of the ink remains down inside the burrow.

Scabies is often mistaken for other itchy rashes, particularly if only one child is affected. The main problem is that by the time you see your pediatrician, your child's itching has usually 'ruined' the burrows, which are the most of the characteristic parts of the rash.

Be sure to ask your pediatrician about scabies if your child has an intensely itchy rash, especially if other family members or close contacts have or have recently had the same rash. Since it can take 4-6 weeks for the rash to develop, keep in mind that all family members may not have symptoms at the same time.

Treatments for Scabies

The typical treatment for scabies involves applying 5% permethrin cream or lotion (Elimite) to a child's entire body from the neck down. Keep in mind that infants may need to have their head treated too, including their hairline and scalp. The cream or lotion is left on for 8-14 hours and then washed off and then a second treatment may be needed a week later. Close contacts, including all family members, should also be treated at the same time.

Although the Elimite will kill the mites, your child may also need treatment for the rash.

This can include topical steroid creams, oral antihistamines, and other anti-itch treatments.

Since the mites can live for 48-72 hours on clothing, bedding, towels, etc., should be washed in hot water and then dried in a hot dryer. Things that can't be washed can be placed in a plastic bag for a few weeks to make sure the mites have died. Furniture and carpeting should also be vacuumed carefully.

What You Need To Know

  • The rash that is seen with scabies is an allergic reaction to the scabies mite and its eggs and droppings.
  • Scabies spreads through prolonged skin to skin contact, and so is more common in kids in daycare or school or family members of a person with scabies.
  • Pets don't become infected with the same mite that infects people. They get a different mite that can't survive on humans and only causes a rash for a few days that goes away without any treatment.
  • Itching may continue for 2-3 weeks after scabies is successfully treated although you shouldn't see new bumps or burrows after being treated.
  • All close contacts of a person with scabies should also be treated at the same time, even if they aren't showing symptoms yet.
  • Norwegian or crusted scabies is a severe form of this infestation that is most commonly seen in people with a weakened immune system.
  • It takes about ten days for a mite's eggs to hatch and become adult mites, which can lay eggs and continue the cycle.
  • Lindane, which used to be the primary treatment for scabies, is rarely used now because of the risk of serious side effects.