Medical Review By: Ted Schiff, MD
If your skin has red bumps that are mighty itchy, the cause could be a mite. Here’s what to know about the contagious infestation known as scabies and how to recognize it so you or your child can get treated before the itching becomes unbearable.
What is scabies?
Scabies is a skin condition caused by an infestation of microscopic eight-legged mites called Scarcoptes scabiei. The mites cause extreme itching and a rash. Symptoms develop after pregnant female mites burrow into the skin and lay eggs. When the eggs hatch, the young mites return to the surface of the skin via the burrows created by the females. Without treatment, the cycle repeats itself as the young mites mate and tunnel under the skin to lay their eggs.
What does scabies look like?
The scabies rash takes the form of small, red bumps that may look like pimples, bug bites, hives or knots under the skin. You might be able to see the burrow tracks created by the mites, which appear as raised lines of tiny blisters or bumps. Some people develop scaly patches that resemble eczema.
Because the rash is so itchy, sores may result from constant scratching and can become infected. Itching is worse at night and can interfere with sleep.
A less common and more severe type of scabies called crusted or Norwegian scabies happens when an exceptionally large number of mites invades the skin. There may be hundreds or thousands of mites compared with only 10 or 20 in typical scabies. People with crusted scabies develop thick crusts of skin that contain mites and eggs. They may or may not experience itching and a rash.
Once someone has been exposed to scabies, symptoms develop four to eight weeks later. (In someone who’s had scabies before, symptoms may develop in just a few days.) It’s possible to spread scabies to others during the pre-symptomatic stage as well as the symptomatic stage.
Adults who contract scabies tend to develop the rash in certain areas of the body, which include:
- Between the fingers
- Inner elbows
- Sides of the wrists
- Around a nipple
- Male genitals
- Soles of the feet
- Areas covered by jewelry like bracelets, watches and rings
Infants and very young children are more likely to get scabies on the:
- Soles of the feet
How do you get scabies?
Scabies is transmitted by prolonged skin-to-skin contact with someone who has it. A quick hug or handshake is unlikely to spread scabies; you’re more likely to get it from a member of your household or through sexual activity. You can also contract scabies by touching personal items that someone with scabies has used, such as towels, furniture, bedding and clothing, though this mode of transmission is less common. You cannot get scabies from an animal that has mites.
Who gets scabies?
Scabies has nothing to do with poor personal hygiene or dirty surroundings. In truth, anyone can get it. People who are more vulnerable to contracting scabies include:
- Mothers of young children
- Sexually active young adults
- People who live in group settings, such as nursing homes, assisted living facilities and extended care facilities
- Elderly people
- People with a weakened immune system
- People who have received an organ transplant
Crusted (Norwegian) scabies primarily affects elderly people and those with a weakened immune system, disability or neurological condition. It’s more contagious than typical scabies because it spreads via person-to-person contact and also through the shedding of the skin crusts. When crusts fall off, the mites inside can survive for up to a week, which gives them time to find another host.
If you suspect you might have scabies, see a dermatologist promptly. He or she will check for signs of mites and may take a skin scraping from the area and look for mites and their eggs under a microscope.
Scabies is treated with prescription medications called scabicides, which kill the mites. Permethrin 5% is the most commonly prescribed scabicide. While these medications kill mites quickly, the itching may last for several weeks. Skin usually heals within four weeks.
Treating crusted scabies is more challenging, and treatment may last for several weeks or longer if necessary. People with crusted scabies may be prescribed both a scabicide and another mite killer called benzyl benzoate, along with a keratolytic cream, which helps reduce crusting of the skin and allows for better absorption of permethrin or benzyl benzoate.
Some scabies patients may be prescribed additional medications such as an antibiotic (if an infection is present) and medications to help control itching, such as a steroid cream and antihistamine.
Because scabies is highly contagious, your dermatologist may recommend that members of your household and your sexual partner(s) be treated for scabies as well. You’ll also need to do a thorough cleaning of your home, including vacuuming floors, rugs and all upholstered furniture. (Discard the vacuum bag afterward.) Items such as towels, sheets, blankets and clothing should be washed in hot water and dried on high heat or dry-cleaned. Another option is to seal the items in a plastic bag for at least 72 hours, since mites that aren’t in skin crusts die within a few days without a host.
The good news is there’s no need to use insecticides or fumigants to get rid of mites — in fact, the Centers for Disease Control and Prevention doesn’t recommend them — so you don’t have to expose your family to these chemicals or endure their odor to make your home safe again. And, since the scabies mite can’t survive on animals, there’s no need to treat your pet.
Article Written By: Jessica Brown is a health and science writer/editor based in Brooklyn, New York. Her work has appeared in Prevention, Johnson & Johnson, the Breast Cancer Research Foundation and many more.
*Wikimedia Commons photo licenses:
Thorax scabies: Fhgd/Wikimedia Commons
Hand scabies: Fhgd/Wikimedia Commons