What is scabies?
Scabies is a common, itchy skin reaction caused by a mite (Sarcoptes scabiei) that affects only humans. The mite is very small and can only be seen under a microscope. The female mites burrow under the skin to feed and lay eggs. These mites cannot jump or fly, and in most cases can only survive for less than three days off the body. An infested person typically has only 10-15 mites on their body. Scabies is found worldwide and affects people of all races and social classes.
What are the symptoms of scabies?
Symptoms of scabies include an extremely itchy rash, with red bumps and burrows in the skin that look like thin, wavy, gray or white lines. Common places on the body where the rash and burrows are seen are between the fingers, around the wrists and elbows, the armpits and around the waistline, although scabies can be found on other areas of the body too. In infants and young children, the head, neck, palms of the hands and soles of the feet may also be affected.
The rash is extremely itchy, especially at night. The itching is caused by a reaction to the mites, their eggs and their waste. Although the mites themselves are not dangerous, scratching the rash may lead to skin infections that can be dangerous.
Symptoms may occur two to six weeks after coming in contact with the skin of an infested person or their personal items. However, a person who has previously had scabies may have symptoms within several days.
How is scabies spread?
Scabies is spread through direct, skin-to-skin contact with a person who is infested with the mites or through skin contact with the clothes or bedding of an infested person. Exposure is most common in nursing homes, hospitals or daycare settings. Scabies can also be spread in households and through sexual contact. Mites can burrow under the skin in several minutes. Spread can occur until all of the mites and eggs are destroyed by treatment.
How is scabies diagnosed?
A health care provider should be seen if a scabies infestation is suspected. He/she can diagnose scabies by looking for the burrows or rash. A skin scraping may be taken to look for the mites, their eggs or feces.
How is scabies treated?
A doctor can prescribe an appropriate skin lotion to treat scabies. There are several lotions available, and the lotion should be used as instructed. A second treatment may be prescribed 7-10 days after the first (to kill any hatching eggs), depending on the type of lotion and the severity of the infestation.
The doctor may choose to treat all members of the household at the same time to prevent spread and re-infestation.
The rash and itching may not go away right after treatment, but this does not mean the treatment did not work. These symptoms may last for several weeks after treatment. A doctor may prescribe medication to help the itching.
All clothing (especially underwear and pajamas) bedding and towels that have come in contact with the infested person’s skin in the three days prior to treatment should be machine washed with detergent in hot water and dried in a dryer with heat. Any items that cannot be washed, like stuffed toys and pillows, should be placed in tightly closed plastic bags for at least 72 hours before using again. This leads to the death of any mites in these objects. Carpets and upholstered furniture should be thoroughly vacuumed.
Check companions, household members and sexual partners for evidence of infestations. Those with skin-to-skin contact should be treated to prevent scabies.
How can scabies be prevented?
Avoid skin-to-skin contact with anyone who has recently been diagnosed with scabies, and do not share their clothes, bedding or towels. Children who have been diagnosed with scabies should not return to school until treated.
What is Norwegian scabies?
“Norwegian (or crusted) scabies” is the name given to a very bad case of scabies (caused by the same mite). It is uncommon and causes widespread, crusted wounds on the body. People with weakened immune systems, the elderly, and people who do not have itchiness from scabies are more likely to get Norwegian scabies. People with Norwegian scabies are more likely to transmit mites because of the large number of mites that they carry and the widespread contamination of bedding, clothing and other objects they contact.
Where can I get more information about scabies?
- Your doctor or nurse
- The Centers for Disease Control and Prevention (CDC) website at: http://www.cdc.gov/parasites/scabies/index.html
- Your local board of health (listed in the telephone directory under “government”)
- The Massachusetts Department of Public Health (MDPH) Division of Epidemiology and Immunization, (617) 983-6800 or the Division of STD Prevention, (617) 983-6940.