Scabies

The aim of this leaflet

This leaflet has been written to help you understand more about scabies. It will tell you what it is, what causes it, what can be done about it, and where you can find out more about it.  

What is scabies?

Scabies is a common and very itchy skin condition caused by human scabies mites. It can affect people of any age but is most common in the young.
 
Scabies may also occur during pregnancy; however the course of pregnancy will not be altered by scabies and the unborn baby will not be affected by it.  

What causes scabies?

The mites that cause scabies are tiny eight-legged parasites, smaller than a pinhead. They are usually picked up by prolonged skin-to-skin contact with someone who already has scabies, and only very rarely from objects such as clothing or bedding. Pets do not spread them. People with scabies have an average of about a dozen adult mites on their skin; a few carry many more. Being dirty does not cause scabies. 

Is scabies hereditary?

No, but it is common for several members of a family to have it at the same time.  

What are the symptoms of scabies?

Itching is the main symptom of scabies, usually starting about a month after the mites were picked up. The itching affects the body and limbs but usually spares the head and neck, except in infants. The itch often gets worse in bed at night. It is common for several people in the same family, partners, and their friends, to become itchy at roughly the same time.  

What does scabies look like?

The rash of scabies is a mixture of scratch marks and red scaly areas; later it can become infected and develop small pus spots. This itchy rash covers much of the skin, but the mites themselves show up mainly where they burrow along, just under the skin surface, to deposit their eggs – for example on the sides of the fingers and hands, and around the wrists, ankles, feet, breast and genitals. Their burrows are inconspicuous thin greyish wavy lines of up to 1cm in length. Adult mites are tiny, only about 0.4 mm long, appearing through a magnifying lens as a tiny dark dot lying at the less scaly end of such a burrow. 

How is the diagnosis of scabies made?

Your doctor will usually be able to diagnose scabies on the basis of the story and the type of the rash. The best way to confirm the diagnosis of scabies is for a doctor to pick out a mite from its burrow with a needle and to identify it under the microscope. Alternatively scrapings from a burrow can be looked at in the same way for mites and their eggs. 
Can scabies be cured?
If it is not treated, scabies lasts for months or even years; but with the right treatment, it clears up quickly and completely. Remember that, even after the mites have been killed, the itching may go on for a few weeks after the treatment has been completed.  

How should scabies be treated?

The treatment of scabies falls into two, equally important, halves:
1. Getting rid of your own scabies.
2. Making sure that you and other contacts don’t catch it again. This means that all family members and sexual contacts must be treated too, whether they are itchy or not. Several preparations are effective in the treatment of scabies. It is worth checking that the preparation you have been given is one specially designed for use in scabies (not for head lice). Follow in detail the instructions issued with your treatment. They will be based on the following principles:
• The mites may be anywhere on the skin, so the treatment must be applied to all areas - including the scalp, neck, face and ears, under the nails, and on soles of the feet - not just to the itchy parts.
• Taking a bath or shower before treatment is not recommended.
• The treatment should be left on for at least 12 hours before being washed off.
• When you wash your hands, put the treatment on them again afterwards.
• Two treatments, one week apart, will deal with mites that have hatched out from eggs during that time.
• Ordinary laundering will deal with bedding and clothing. Any clean clothes hanging in the closet or folded in the drawers are OK.
 
The recommendations as to the best and safest medications in pregnancy are 
. Benzyl benzoate 25% lotion: apply Benzyl benzoate 25% lotion on 3 consecutive days, then wash off.  Re-treat hands if washed with soap in between

. Crotamiton: apply Crotamiton 10% ointment or lotion on 3-5 consecutive days, then wash off; re-treat hands if washed with soap in between

. Malathion 0.5% lotion: apply Malathion 0.5% lotion, wash off after 24 hours; re-treat hands if washed with soap in between

. Permethrin 5% cream. Permethrin seems more effective, there are no studies that prove absolute safety. Apply Permethrin 5% cream, wash off after about 12 hours; re-treat hands if washed with soap in between. 


The treatments should be repeated after 7 days
Pump sprays should be avoided because of the danger of breathing in the medication.
 
Permethrin seems more effective, there are no studies that prove absolute safety. Benzyl benzoate, Malathion, and Crotamiton seem less effective,but  they are considered safe; however, large studies are lacking
 
Antihistamines to treat the itch are considered safe:
Non-sedating: Loratadine, Cetirizine
Sedating: Clemastine, Dimethindene, (Dex)chlorpheniramine
 
Short courses of steroid creams or ointments to treat itching rashes after scabies can be used. Hydrocortisone acetate 1% cream or ointment and other mild to moderate corticosteroids (one to 2 small tubes) are considered safe.  

What can I do?

If you follow the instructions you are given, you will clear your scabies successfully. You must also make sure that all of your close contacts, with no exceptions, really do get their treatments and apply them. Their treatment should start at the same time as yours, and should be put on just as thoroughly. Much time and effort can be wasted if anyone escapes the net, or if they fail to treat themselves properly. Catching scabies again is, unfortunately, quite common.  

Where can I find more information about scabies?

Web links to detailed leaflets:
www.emedicine.com/emerg/topic517.htm
http://www.aad.org/dermatology-a-to-z/diseases-and-treatments/q---t/scabies
www.medinfo.co.uk/conditions/scabies.html
 
Books:
Schaefer, Spielmann, Vetter. Arzneiverordnung in Schwangerschaft und Stillzeit. 8th edition, 2012 (Germany)
Schaefer, Peters, Miller: Drugs during pregnancy and lactation. 2nd edition 2007 (English) (3ed edition in preparation)
Briggs, Freeman, Yaffe.  Drugs in pregnancy and lactation. 7th edition, 2005 (USA)
 
While every effort has been made to ensure that the information given in this leaflet is accurate, not every treatment will be suitable or effective for every person. Your own doctor will be able to advice in greater detail. The general information of this leaflet is adapted from the BAD patient information leaflet. Recommendations on treatment in pregnancy are prepared according to recommendations from German, Dutch, UK, and US teratology services. 
 
This leaflet has been prepared by the EADV task force “skin disease in pregnancy”, it does not necessarily reflect the official opinion of the EADV
 
Updated 26.05.2013