Scabies

You say skay-bees

Scabies is an intensely itchy skin rash. It is caused by an allergic reaction to a tiny insect (called a mite), which burrows under the skin surface. Scabies is easily spread and will not go away without treatment.

Key points about scabies 

  1. Scabies is spread through skin-to-skin contact with an infested person, or through shared bedding or clothing.
  2. You need to treat scabies with a lotion or cream called permethrin. It won’t go away on its own.
  3. Everyone who lives in the same household as the infested person needs to be treated.
  4. Decontaminate all clothing and bedding by washing in hot water.
  5. The itch may continue for a few weeks even though the mite is gone. See your doctor if itchiness continues for longer than 6 weeks.

What causes scabies?

Scabies is caused by tiny insects (mites), which burrow along just under the surface of the skin, laying eggs as they go. Scabies mites are so tiny, you can't see them with the naked eye.

The itchy rash is due to an allergic reaction to the scabies mite, mite poo (faeces), and mite eggs.

How do you get scabies?

Anyone can get scabies. It is not due to poor hygiene. Scabies is more common when you have lots of people together in close contact. Sometimes outbreaks of scabies occur in places such as kindys and residential homes, where people are in regular close contact. Washing with soap will not prevent or cure it.

Scabies is usually spread by direct, prolonged skin-to-skin contact with a person who has scabies. Contact generally needs to be prolonged – you are unlikely to get scabies from a quick handshake or hug.

Scabies is spread easily to household members and sexual partners.

Scabies can also be spread by sharing articles such as clothing, towels, or bedding used by an infested person.

How do you know if you have scabies?

One of the first symptoms of scabies is a very itchy rash. This is usually worse at bedtime or when you are warm, such as when you are in bed, or after a shower.

Symptoms generally start 3 to 6 weeks after infestation. However, if you’ve had scabies before, then the rash can start after only 1 to 3 days

The scabies rash generally looks like multiple small red bumps that can appear anywhere on the body. The most common sites are between the fingers, on the wrists, inside the elbows, around the waist, on the bottom or private parts and under the armpits. The rash does not usually appear on the head except in very young children. Many conditions can cause a similar rash and so it can easily be confused with other skin conditions such as dermatitis or hives.

Not all people who have the scabies mite have itching. A person can spread scabies, even if they do not have symptoms, until they are successfully treated and the mites and eggs are killed.

If you are not sure if you have scabies, talk to your doctor, a nurse or a pharmacist.

Images of scabies


See more images of scabies from DermNet, NZ. 

Sites where scabies mites are commonly found:

 

Why is it important to treat scabies?

Scabies will not go away without treatment.

Scratching a lot can make skin conditions such as eczema or psoriasis worse and it can also lead to skin infections such as impetigo or cellulitis.

Go to the doctor if the sores or rash get redder, warm, start swelling, have pus, or you develop a fever. This could indicate a possible bacterial skin infection that needs treating with an antibiotic or other therapy.

How do I get rid of scabies?

Scabies will not go away without treatment.

Scabies is usually  treated with a cream or lotion called permethrin. Permethrin is an insecticide that kills the scabies mite. You can buy this from your pharmacy or get it on prescription from your doctor. It is safe for use in pregnancy, breastfeeding, and infants over the age of 2 months. You need enough cream/lotion to treat everyone in the household. One 30 gram tube is generally enough for an average sized adult.

Permethrin may not be suitable for everyone – you may need a different treatment

See you doctor for advice before treatment if you:

  • have open wounds or skin infections
  • have crusted scabies (severe infestation)
  • are bed-bound
  • are caring for a child under 2 years of age
  • are pregnant.

How to apply permethrin cream/lotion to treat scabies

Everyone living in the house should be treated at the same time even if they are not itchy.

  • Permethrin must stay on the body for at least 8 hours (up to 12 hours) to kill the mites.
  • Apply the cream/lotion just before going to bed. Make sure your skin is cool and dry.
  • For adults and older children: Cover every patch of skin over the whole body, from the neck-line down to the toes, including the scalp, face, neck, ears down to the soles of the feet. Pay particular attention to the areas between the fingers and toes, wrists, armpits, belly button, genitals and buttocks.
  • Leave the cream/lotion on overnight.
  • If you wash your hands during the night, reapply cream/lotion to your hands.
  • In the morning have a shower and wear clean clothes.

Repeat the treatment: another application of permethrin treatment is often needed one to two weeks later. Don’t apply permethrin treatment more than twice without medical advice. Overuse can irritate the skin.

You or your child can go back to work or school 24 hours after the first treatment.

Read more about permethrin.

On the morning after everyone in your household has been treated

Wash all clothing, sheets, towels and pillowcases anyone has used in the past week in hot water (50°C for at least 10 minutes). If you have a tumble drier, dry all items on the hottest tumble dryer setting for 20 minutes.

If clothes or linen cannot be washed either:

  • dry clean, or
  • seal in plastic bag for 7 days at room temperature, or
  • seal in plastic bag and freeze overnight.

If you don’t do these things, the mites will reinfest your family.

Note: the mite is not small enough to go through the weave of sheets, so under blankets and mattresses do not need to be cleaned.

I have used scabies treatment – why am I still itchy?

Although the treatment kills the scabies mites quickly the itching can carry on for a few weeks.

The intense itch generally improves by one week of treatment. However, it can take 4 to 6 weeks for the itch and rash to clear completely even though all mites have been killed. Treat itchy patches with oral antihistamines, moisturisers or mild topical steroids. See a doctor if your skin is still itching 6 weeks after treatment.

Other reasons you may still be itchy include:

  • The diagnosis may be incorrect. Scabies can be confused with a number of other skin conditions, particularly dermatitis and hives. Celiac disease is another cause of a persistently itchy rash.
  • It may be necessary to repeat the scabies treatment. Talk to your pharmacist or doctor for advice. Do not repeat treatment more than two times without medical advice. Overuse of insecticides such as permethrin can irritate the skin.
  • Resistance to treatment. Scabies occasionally appears to be resistant to the prescribed scabies treatment.  You may need to try a different treatment - talk to your doctor.   

Learn more

Scabies Derm Net NZ, 2015
Scabies summary, symptoms, treatment, prevention NZ Ministry of Health

Reviewed by

Jeremy Steinberg is a GP with special interests in musculoskeletal medicine, evidence-based medicine and use of ultrasound. He's been reviewing topics for Health Navigator since 2017 and in his spare time loves programming. You can see some of the tools he's developed on his website.

Credits: Health Navigator Editorial Team. Reviewed By: Dr Jeremy Steinberg, FRNZCGP Last reviewed: 19 Jul 2019