Hopkins 24/7

Back to ABC News

This Thursday at 10/9c

This content requires javascript and flash player version 8.

Johns Hopkins Symptoms and Remedies

Johns Hopkins Medicine

Close Article Browser

Scabies

What is it?

Scabies is a disorder caused by a skin infestation of a burrowing mite. The tiny mite digs under the uppermost layer of the skin and lays several eggs. The skin becomes sensitized to the mite over a period of several weeks to several months, until finally a skin eruption of small blisters occurs, causing intense itching. Scratching may collect the mites and eggs under the fingernails and help transmit them to other parts of the body. The warm folds of the skin, such as those of the wrists, the underarms, the genitals and the webs between the fingers, are most commonly affected. In infants and small children, the blisters may be more generally distributed, appearing on the face and neck, palms, and soles.With treatment, itching usually subsides quickly, and all traces of the disease generally disappear within two to four weeks.

What Causes It?

  • The female mite burrows into the upper layer of skin and lays two or three eggs daily for up to 60 days if undetected or untreated.Within three weeks newly hatched larvae mature and begin a continuing cycle of infestation. Itching is due to a reaction to the mite and its products.
  • Physical contact with an infested person or with contaminated clothing or bedding may spread scabies. (Casual transmission, as between schoolmates, is uncommon.) Family members and bed mates are at the highest risk. Children under 15 are usually the first members of the family to get scabies.
  • Crowded, institutional, or unsanitary living conditions also increase the risk.

Prevention

  • Practice good personal hygiene; wash clothes and bedding often.
  • Avoid physical contact with persons, clothing, or bedding that may be infested with scabies.

Diagnosis

Diagnosis is suspected upon visual inspection of burrows or lesions. * Microscopic examination of a skin scraping confirms the diagnosis.

How to Treat It

  • Permethrin cream should be applied after the skin has cooled following bathing. The medication is left on overnight and thoroughly washed off in the morning. This regimen is repeated once 7 days later.
  • Oral antihistamines (like diphenhydramine) may help ease itching, as may topical emollients.
  • Antibiotics may be required to treat secondary bacterial infections.
  • Bed linen and clothes used for two to three days prior to treatment should be thoroughly washed in hot water.
  • Family members, even those without symptoms, should be treated at the same time as the patient.
  • Itching may persist following successful treatment due to an allergic reaction to the medication.

When to Call a Doctor

Call a doctor if you experience intense itching and over-the-counter remedies fail to relieve it.