Ira Pion, MD
Ira Pion, MD, is a clinical assistant professor of dermatology at NYU Medical Center and a partner in private practice in Woodmere, New York. NRPDerm.com
What is that itchy rash with small raised red spots? It might be an indication that you’ve caught scabies, an infestation of microscopic mites that burrow into the skin and lay eggs. Bottom Line Personal asked Ira Pion, MD, clinical assistant professor of dermatology at NYU Medical Center, how to identify scabies…what causes them…and, most important, how to get rid of them fast.
These tiny mites burrow into the skin and lay eggs. The eggs hatch…the larvae grow into egg-laying adults…and the colony lives on. The itchy scabies rash is the body’s allergic reaction to the mites.
Scabies mites, Sarcoptes scabiei var. hominis, do not crawl or jump like fleas. They pass between people through prolonged skin-to-skin contact, not casual social interaction, so it’s often spread between sexual partners or close family members. And, unlike bedbugs, they can’t live much beyond a day outside the human body.
If you’ve never had scabies, the rash won’t appear until four to six weeks after exposure. In people who’ve had scabies in the past, the immune system “remembers” the parasite and the rash and itch appear much sooner.
The intensely itchy scabies rash appears typically in the webs of the fingers, the folds of the wrists and elbows, the waistline, the nipples, the navel and the genital area. In infants, the scabies rash may appear on the face, palms and soles. A classic scabies symptom is a red line on the skin where mites have burrowed. While finding a burrow helps confirm diagnosis, they aren’t visible in every case.
Depending on severity of the immune response, patients might develop nodules, especially in the groin and armpits, or crusts on the skin. Vigorous scratching sometimes leads to open sores that may become infected with bacteria.
If you suspect scabies, see a dermatologist. He/she will confirm the diagnosis by analyzing a skin scraping under a microscope.
The key treatment is a prescription medication that kills the mites. This medication must be taken exactly as instructed. Topical treatments include permethrin, malathion and spinosad (Natroba), which require careful application from the neck down and must be left on for either eight or 24 hours. Permethrin and malathion don’t destroy the mites’ eggs so they must be reapplied after a week to kill any new hatchlings. Another medication, ivermectin, is taken in pill form.
Scabies mites have developed resistance to some of these medications, so your doctor may need to try different options. Important: Your whole household, even members who are asymptomatic, should get treated simultaneously so you don’t keep re-exchanging the mites.
Your doctor also may prescribe a steroidal cream to relieve itching. Caution: Don’t assume you’re cured just because the itch is soothed. Mites and eggs remain under your skin until you’ve properly used medication to eradicate them.
Although scabies mites don’t live very long outside the body, some might persist on skin cells you’ve recently shed. On the day you’re treated, wash your bedding and any clothes you’ve worn over the past few days in hot water and put them in the dryer. For any items you’ve worn recently that can’t be washed and dried, bag them up and leave them for a week.
