Scabies and Lice: How to Identify and Eliminate These Parasitic Infestations

Itching that won’t quit. A rash that spreads despite showering. Tiny bugs crawling on your child’s scalp. If you’ve ever dealt with scabies or lice, you know how frustrating-and embarrassing-they can be. These aren’t just minor annoyances. They’re highly contagious parasitic infestations that can turn your home into a battleground. And the worst part? Most people treat them wrong.

What Exactly Are Scabies and Lice?

Scabies is caused by a microscopic mite called Sarcoptes scabiei. These mites burrow under your skin to lay eggs, triggering an allergic reaction that makes your skin itch like crazy-especially at night. You won’t see the mites, but you might notice thin, wavy lines on your skin, usually between fingers, on wrists, or around the waist. In babies and young kids, the rash can show up on the scalp, face, palms, or soles of the feet.

Lice are different. They’re tiny insects that live on the surface of your skin or hair, not under it. There are three types: head lice (most common in kids), body lice (linked to poor hygiene), and pubic lice (often spread through close contact). Head lice cling to hair shafts and feed on blood from your scalp. You’ll spot them as small, moving dots, or find nits-white, oval eggs glued tightly to hair strands near the scalp.

Both are spread by direct, prolonged skin-to-skin contact. Scabies can also spread through shared bedding, towels, or clothing. Lice don’t jump or fly-they crawl. A child getting head lice at school doesn’t mean they’re dirty. It just means they were in close contact with someone who had them.

Why Most Treatments Fail

People often reach for over-the-counter lice shampoos or scrub their skin with soap and water. That’s not enough. Scabies mites burrow deep. Lice eggs (nits) are glued on with a strong protein that regular shampoo can’t dissolve.

The biggest mistake? Treating just the person who’s itching. If one family member has scabies, everyone else in the household needs treatment-even if they feel fine. Mites can live for days without a host. If you don’t treat everyone at the same time, you’re just playing whack-a-mole with parasites.

Another common error: washing off topical treatments too soon. Permethrin cream needs to stay on your skin for at least 8 hours. Most people rinse it off after 2 or 3 because it’s messy and uncomfortable. But if you don’t give it enough time, you’ll miss the mites and their eggs.

What Actually Works: The Science-Backed Treatments

There are two proven first-line treatments for scabies: permethrin cream and oral ivermectin.

Permethrin 5% cream is the gold standard. It’s applied from the neck down, covering every inch of skin-including between fingers, under nails, and in skin folds. Leave it on for 8 to 14 hours, then wash it off. A second application is recommended 7 days later to catch any newly hatched mites. Studies show it cures about 92.5% of cases when used correctly.

Oral ivermectin is a pill taken with food to help your body absorb it. The dose is based on weight: 200 micrograms per kilogram. You take one dose, then another 7 to 14 days later. It’s especially useful for people who can’t apply cream (like those with severe eczema or dementia) or in outbreaks like nursing homes. One study of 242 patients found a single dose cured 85.9% of cases. After a second dose, it reached 100%.

For lice, permethrin lotion (1%) is the go-to. But resistance is growing. In some U.S. regions, up to 30% of head lice no longer respond to permethrin. That’s why newer options like spinosad 0.9% liquid are becoming popular. It kills both lice and eggs in one application and doesn’t require combing out nits. It’s approved for kids as young as 4.

For stubborn cases, doctors may prescribe ivermectin pills for lice too. A double dose (0.4 mg/kg) has been shown to be 95-100% effective against head lice in field studies.

What Doesn’t Work (And Why You Should Avoid It)

Don’t use lindane lotion. It’s FDA-approved but rarely used because it can cause seizures, especially in children and people with skin conditions. It’s also been pulled from the U.S. market entirely.

Home remedies like mayonnaise, olive oil, or vinegar? They might suffocate some lice, but they don’t kill eggs. You’ll end up combing for weeks with no real progress.

And don’t spray your house with bug bombs. Scabies mites don’t live long off the body. Lice can’t survive more than 1-2 days without a human host. Washing clothes, bedding, and towels in hot water (at least 130°F) and drying them on high heat is enough. Items you can’t wash? Seal them in a plastic bag for 72 hours.

Special Cases: Crusted Scabies and Co-Infections

Some people develop a severe form called crusted (or Norwegian) scabies. It’s rare but dangerous. The skin becomes thick, scaly, and covered in millions of mites. This happens mostly in older adults, people with weakened immune systems, or those living in crowded settings.

Treating crusted scabies requires more than one treatment. Doctors combine oral ivermectin with topical permethrin. Sometimes, they give multiple doses of ivermectin over several weeks. It’s not something you can handle at home-hospital care is often needed.

There’s also growing evidence that treating scabies and lice together can be more effective. In the Solomon Islands, health workers gave people both azithromycin (for trachoma) and ivermectin (for scabies) in the same program. Results? Over 95% of scabies cases cleared up. This approach is now being tested in other tropical regions where multiple parasitic infections overlap.

How to Prevent Reinfestation

Treatment only works if you stop the cycle. Here’s what you must do:

• Treat everyone in your household at the same time-even if they have no symptoms.
• Wash all bedding, clothing, and towels used in the last 3 days in hot water and dry on high heat.
• Items that can’t be washed? Put them in a sealed plastic bag for 72 hours.
• Don’t share combs, hats, hairbrushes, or towels until you’re sure the infestation is gone.
• Check everyone’s skin and hair again after 7-10 days. If you still see live bugs or new burrows, call your doctor.

For schools and daycare centers, the CDC doesn’t recommend "no-nit" policies. Kids can return to class after one treatment. The real risk is ongoing exposure-not a few leftover nits.

What to Expect After Treatment

Even after the mites and lice are dead, itching can last for weeks. That’s because your body is still reacting to their remains. Don’t assume it means treatment failed. Use over-the-counter hydrocortisone cream or antihistamines to ease the itch. If the rash gets worse, turns into sores, or you develop a fever, see a doctor-you might have a secondary infection.

For lice, you might still see nits after treatment. That’s normal. Dead nits are white and stick firmly to the hair. Live ones are brown and closer to the scalp. You don’t need to remove every single one unless it’s bothering you.

When to See a Doctor

You don’t always need to go to the clinic. But you should if:

• After two full rounds of treatment, you still see live bugs.
• The skin is cracked, oozing, or covered in pus (signs of infection).
• Someone in your home has crusted scabies or a weakened immune system.
• You’re pregnant or nursing and need treatment.
• Your child is under 2 years old-some treatments aren’t approved for infants.

Doctors can prescribe stronger options, check for complications, and help you avoid the trap of repeated, ineffective treatments.

The Bigger Picture: Why This Matters Beyond Your Home

Scabies affects an estimated 204 million people worldwide every year. The World Health Organization calls it a neglected tropical disease. In places like Papua New Guinea, the Solomon Islands, and parts of Africa, entire communities are affected. Mass treatment programs using ivermectin have cut scabies rates by over 60% in some areas.

It’s not just about comfort. Untreated scabies can lead to serious skin infections like impetigo, which can damage kidneys and hearts-especially in children. Lice, while less dangerous, can cause sleep loss, school absences, and stigma.

What we’re seeing now is a shift from treating individuals to treating communities. The future of parasite control isn’t just about better drugs-it’s about smarter, coordinated public health efforts.