Scabies is a common infestation of the skin with a microscopic mite called Sarcoptes scabei. A scabies infestation may look like a rash. See your doctor if you are itching all over your body, especially at night, or if you are scratching enough to cause sores. Sores from scratching could become infected with bacteria.
Scabies rashes often show up as tiny pimples or burrows. Look for the rash in skin folds:
- between fingers
- on wrists
- shoulder blades
For a person who has never been infested with scabies, symptoms may take 4 to 6 weeks to begin. For a person who has previously had scabies, symptoms appear within several days.
Scabies are diagnosed by looking at the rash. Your doctor may take a scraping of your skin to look for mites, their fecal matter or eggs. Most infestations consist of few actual mites -- as few as 10 per person -- so it's easy to miss an infestation by looking at skin scrapings. Those with Norwegian or crusted scabies can have thousands of mites and are highly contagious.
Scabies spreads by prolonged skin-to-skin contact and by sharing clothing, towels and bedding. Casual contact such as a quick hug or handshake is usually not enough to spread scabies. It's easily transferred between sexual partners and residents of the same house or institution.
Scabies spreads rapidly in crowded conditions like nursing homes, prisons, day-cares and hospitals. These populations often have weakened immune systems or are elderly, and may get a more severe form of scabies -- called Norwegian or crusted scabies -- that is spread more easily.
Once away from the human body, mites usually do not survive more than 48 to 72 hours. When living on a person, an adult female mite can live up to a month.
Cats, dogs and other small animals also get scabies, although it is a different mite from the same family. Humans can indeed get scabies from their pets. But the different mites usually cannot reproduce and the infestation disappears once the pet is treated. There have been cases of people with continued infestations even after the animal was successfully treated. It's important for your doctor to know if you have a pet with scabies (also known as mange).
Treatment requires a prescription cream or lotion. Contact your doctor if you think you may have scabies. There are other causes of itching, the most dangerous being an allergic reaction. If you have itching and begin to develop shortness of breath, call 911 or go to the emergency department immediately.
Always follow the medication's directions or your doctor's directions. You will usually need to take a shower before you start the cream or lotion. Put the lotion on your clean body from the neck to the toes and leave it on for the recommended time. Take another shower to wash it off. Put on clean clothes and wash -- in hot water and dried with a hot dryer -- all clothing, bedding and towels used by the infested person within the last 3 days.
Besides the infested person, sexual partners and people who have close long-term contact should also be treated. Everyone who needs treatment should get it at the same time to prevent reinfestation. Pregnant women and kids will usually get a milder version of the medication. After treatment, itching may continue for another 2 to 3 weeks. Ask your doctor about possible medication for itching if desired.
McCarthy, J.S., et al. "Scabies: more than just an irritation." Postgrad Med J. 2004.
Rabinowitz, P.M., Z. Gordon and L. Odofin. "Pet-related infections." Am Fam Physician. 1 Nov 2007.
"Scabies Fact Sheet." Nov 10 2008. Centers for Disease Control and Prevention. CDC. 21 Dec 2008.