Scabies

Scabies: Symptoms, Treatment and Stopping the Spread

Scabies is caused by Sarcoptes scabiei, a mite too small to see with the naked eye, which tunnels just beneath the surface of the skin to lay its eggs. It passes mainly through prolonged skin-to-skin contact, so it moves easily through households, between partners and around care homes, nurseries and shared accommodation. It has nothing to do with poor hygiene.

Recognizing Scabies

After a first infestation, symptoms take two to six weeks to appear while the immune system becomes sensitized to the mites. After a repeat infestation they can start within a few days.

• Intense itching that is worse at night or after a hot bath
• Burrows: short, thin, wavy gray or silvery lines, often in the webs between the fingers, on the wrists and around the elbows
• A rash of small raised spots around the armpits, waist, buttocks and nipples, and firm itchy lumps on the genitals
• In babies and young children, the palms, soles, face and scalp may be affected

Scratching can let bacteria in and lead to impetigo or other skin infections. Doctors usually diagnose scabies by examining the skin, sometimes with a magnifier or a skin scraping.

Crusted scabies

In older people and those with weakened immunity, scabies can produce thick gray crusts that contain huge numbers of mites. Crusted (Norwegian) scabies is highly contagious and needs medical care, usually repeated topical and oral treatment together.

Treatment Options

Permethrin 5% cream: first choice

Most guidelines recommend permethrin 5% cream as first-line treatment:

• Apply it to cool, dry skin over the whole body from the neck down, including between the fingers and toes, under the nails, the soles of the feet and the genitals. Older adults, young children and people with weakened immunity may be advised to treat the scalp, face and ears as well, avoiding the eyes and mouth.
• Leave it on for 8–12 hours, usually overnight, then wash it off. Reapply to your hands if you wash them in the meantime.
• Repeat the application after 7 days to deal with mites that have hatched since.

Permethrin is not sold in this category; ask your pharmacist.

Oral ivermectin: an alternative

Ivermectin tablets are licensed for scabies in some countries and used off-label in others, particularly when creams are impractical or have not worked, during outbreaks, and for crusted scabies.

• The usual dose is 200 micrograms per kilogram of body weight, taken once. For an adult weighing 60 kg that is about 12 mg; your prescriber will work out the right combination of tablets.
• A second dose is taken 7–14 days later, because ivermectin does not reliably kill eggs.
• It is not used in pregnancy or for children weighing less than 15 kg.

Side effects are usually mild, such as dizziness, nausea or a temporary rise in itching as the mites die. Our ivermectin guide covers precautions in more detail.

Ivermectin Tablets in This Range

Smaller strengths make it easier to match the dose closely to body weight.

Treat Everyone at the Same Time

Reinfection from an untreated contact is the most common reason scabies seems to come back.

• Everyone in the household, plus any sexual partners from the previous two months, should be treated on the same day, even without symptoms.
• Wash clothes, towels and bedding used in the three days before treatment at 140°F (60°C), then dry them on a hot setting.
• Items that can't be washed can be sealed in a plastic bag for 72 hours; mites cannot survive that long away from human skin.
• Vacuum mattresses, sofas and carpets.
• Avoid close physical contact until the first treatment has been completed.

Why Itching Continues After Treatment

It is normal for itching to last two to four weeks after successful treatment, because the skin is still reacting to dead mites and their debris. This does not mean the treatment has failed. Moisturizers, a soothing cream or a bedtime antihistamine can help; ask a pharmacist. See a doctor if new burrows appear, if itching is still severe after four weeks, or if the skin looks infected, with weeping, crusting, spreading redness or fever.

Frequently Asked Questions

Can I catch scabies from my dog or cat?

No. Animals carry a different mite that causes mange. It may cause a brief rash in people but cannot establish itself on human skin.

When can my child return to school?

Usually the day after the first treatment has been completed.

Can I get scabies again?

Yes. Having scabies once does not give lasting immunity, which is why treating all close contacts together matters so much.

Everything here is general information and cannot stand in for your own doctor's or pharmacist's advice. Ivermectin must be prescribed; confirm with a healthcare professional that it suits you and everyone being treated.