What is scabies?
Scabies is a strongly itchy skin condition caused by a small mite, Sarcoptes scabiei. This mite lives in the superficial part of the skin, where it digs small burrows. The itch is caused by a reaction of the body against the mite and its eggs.
What does scabies look like?
The main feature of scabies is severe itch. The outward signs consist of the typical very small burrows in the skin, which are visible to the naked eye. Because the scabies mite prefers skin in the body folds, the burrows can best be found there. Scabies is almost never seen on the face or scalp. Typical sites are between the fingers, the wrists, the armpits, the buttocks and the penis. Especially in the armpits and buttocks, red itchy bumps are sometimes seen instead of burrows. In small children the burrows are not always the most striking feature; in them there are more often red bumps that can occur all over the body, and in these cases scabies is sometimes mistaken for eczema or hives.
How do you catch scabies?
The scabies mite is only transmitted after intensive contact between people. Simply shaking the hand of someone with scabies, for example, is not enough to catch the mite. Infection sometimes occurs through sleeping in beds with unwashed bedding in which someone with scabies has previously lain. Scabies otherwise has nothing to do with poor hygiene. There can sometimes be a period of a few weeks between infection and the first complaints.
How is scabies diagnosed?
In typical cases the doctor can make the diagnosis by sight. An attempt is always made to actually demonstrate the mite, by scraping out a burrow with a blade or small sharp spoon and examining the material under the microscope.
How do you get rid of scabies?
Several anti-scabies creams are available on prescription: benzyl benzoate lotion; permethrin cream (the most commonly used); and, nowadays, treatment with ivermectin tablets. Ivermectin is usually reserved by dermatologists for cases where the cream works insufficiently; it is effective in a single dose and is only prescribed when the infection has actually been demonstrated by microscopic examination.
Treatment instructions (permethrin cream)
It is absolutely necessary that all household members are treated, even if they have no itch or rash themselves, and everyone must be treated as soon as possible and at the same time.
- Apply. The whole body (except the face and scalp) is covered with cream — including between the toes, in the cleft of the buttocks, under the (short-cut) nails, and on the genitals. The harder-to-reach folds are exactly the mites’ favourite spots. In children aged 2 and under, the face and scalp are also treated. After applying, the hands must not be washed; it is better not to shower or bathe beforehand.
- Shower. On the morning after applying (8 to 12 hours after the cream), wash the whole body well in the shower. Dry with a clean towel and put on clean clothes.
- Wash clothing. All clothes worn in the past 3 days that can be washed at 60 °C, plus the bedding used in that period, go into the wash. Washing above 50 °C kills the mites. Items that cannot be washed at this temperature must be kept in a sealed plastic bag for at least 3 days; after 72 hours the mites in them are dead.
- Change the bed. The evening after treatment, make up a clean bed: change pillowcases, sheets or duvet cover and mattress protector. The mattress and pillow do not need cleaning. Blankets should be aired for 48 to 72 hours before being used again.
- After treatment. In principle the permethrin treatment only needs to be carried out once, and if the measures are followed carefully the scabies will disappear in almost all cases. The itch can still persist for up to 10 days, and can even temporarily worsen during or shortly after applying the cream — so if the itch does not lessen immediately, it does not mean the therapy has failed. For a lot of itch after treatment, the doctor can temporarily prescribe a corticosteroid cream.
- Treat again? One treatment is usually enough. If new skin lesions appear after a week and there is a real suspicion of a persisting infection, it can be worth repeating the treatment once, again treating all household members and repeating all the steps.
When to see a doctor
See a doctor if you have severe, persistent itch (often worse at night) with a rash in the finger webs, wrists or other folds, especially if others in the household also itch — scabies needs prescription treatment for everyone at once.