Species: Sarcoptes scabei
My doctor has just told me that the rash my daughter has had for a couple of months is scabies. How did she catch it?
Scabies is a contagious infection and is caught by being in skin to skin contact with someone who already has the infection, although they may not know they have it. Something as simple as holding hands will pass the infection on, but so will any other skin to skin contact including intimate sexual contact.
Does that mean she will have passed it on to other members of the family?
It is very likely that she will have passed the infection on to other family members and to other friends with whom she has contact. A lot will depend on how old she is. The most common age group to catch scabies is from under 2 years old to 20 years of age. The very youngest in this group are the most carried and cuddled, young children often hold hands and parents hold hands with their children, young teenagers hold hands when they fall in love and as they become older their relationships become more intimate.
The group next at risk of catching scabies are the older members of society, people such as grandparents in contact with their families and those who are living in care situations whether in the community or in residential care, especially if they are in need of intimate care.
What causes scabies?
Scabies is caused by a small mite, about a 1/60 th of an inch long which burrows just under the surface of the skin, they burrow under the layer that rubs off if you get sunburnt or rub hard with a towel. It is very difficult to see where the burrows are but most of them tend to be on the hands and wrists and between the fingers. The mite is a tiny bump at the forward end of the burrow. Whilst it is possible to see them with the naked eye it is very difficult. The female mite does not leave the burrow voluntarily and it (the tunnel) becomes full of faecal pellets, hatched egg shells and live eggs as she continues to burrow forwards. The infection is very itchy especially at night as you get warm in bed. You can have the mites for between 6-10 weeks before you start to show any signs of the infection though and during this time you can pass it on to other people.
What should I look for on my husband and the other children?
You probably won't notice anything to begin with, but then they will complain of itching, especially around the hands and fingers and around the waist and elbows. Any rashes that develop will always be bilateral, that is in the same places on both sides of the body. So for instance there will be a rash on both knees or elbows not just on one. Men and boys develop nodules on their scrotum and penis, these are absolutely indicative of scabies as no other disease has nodules in these places, they are also extremely itchy.
Will my husband and family need to be treated too?
It is always recommended that all close intimate contacts should receive treatment for scabies at the same time as the person diagnosed even if they are not showing any signs of the disease. Your doctor should have prescribed sufficient treatment to treat everyone in the house. If he hasn't you can buy the lotion or cream at the pharmacists or chemist. You should have enough for two applications as you need to apply the treatment a week later.
Is there a right and a wrong way to apply the treatment?
You should not have a hot bath or scrub the skin before applying the treatment as the aim is to have the treatment in contact with the top layer of skin for as long as possible. As well as being very uncomfortable making the skin hot and the pores open will mean that the lotion or cream is absorbed through the skin and into the blood stream before it has had time to kill the mites.
There are two recognised treatments for scabies. The first, Derbac M or Quellada M, is a lotion, it is best to pour it into a bowl and apply it with a new 3" paint brush and to make sure all the skin areas of the body are covered, even the parts of the body where there is no rash. Although the instructions accompanying the treatment will say to apply from the neck down it is best to include behind the ears, the face and scalp as well as recent research work has shown that 30% of patients have mites in these places too. Be very careful around the eyes, mouth and nose, and don't forget the pubic area, around the anus and under the toe and finger nails. You must put the treatment everywhere there is normal skin.
The second and probably most often used treatment is a cream, called Lyclear Dermal Cream. It is a lanolin based moisturising cream containing 5% permethrin in a 30g tube. It does go a long way but you may need to have two tubes for one application depending on the size of the person needing the treatment. A baby or toddler will not require the whole tube but a teenager will and a much larger person may need two tubes. Once again it will need to be applied from the head down.
As some areas of the body are very difficult to reach if you are treating yourself it is always best to have someone help to apply the lotion or cream to the places you cannot reach such as the centre of the back and around the pubic area and anus.
It is best to apply the treatment before going to bed as it should be left on for at least twelve (12) hours before being rinsed off with cool water, and then having a bath or shower in the normal way. If any area of the body is washed during the treatment time the lotion or cream must be reapplied. e.g. after hand washing and/or a nappy changes.
Will I have to wash all our clothes and bed linen every day whilst we have scabies?
No, there is no need to do that. You might like to wash the bed linen and clothes you were wearing during the treatment time but there is no need to change everything every day because you have scabies, anyway you may not have enough linen to do this.
Will we need to take time off from school and from work whilst we have scabies in the house?
Once the first treatment has been applied and rinsed off your family can go about their normal lives; going to school and to work.
How will I know that the disease is cured?
You will know the infection is cured when no new rashes or spots appear. Unfortunately the itchiness will continue until all the skin containing the mites, the faecal pellets, and its eggs have sloughed off leaving fresh new skin.
Can the scabies mites live in your ears?
No, the skin inside the ear is not suitable for mites to burrow in to. They will however burrow into the skin behind the ear; the post-auricular folds.
Can you catch scabies more than once?
Yes, it is possible to catch this infection more than once but if you were to catch it again the rash and the itching will begin almost immediately. The treatment will be the same as before.
I've heard of people catching something called Norwegian scabies, is this different?
Up to now we have been concentrating on normal or classical scabies. If this is left untreated it will go on to develop into crusted or Norwegian scabies and the incidence of this infection is rising, especially where people are in long term residential care. Patients begin to develop patches of very dry skin or patches of skin that lift off. Sometimes the sufferer has had this for a long time and it has been treated as an allergic reaction, as eczema or dermatitis or as a fungal infection if this patchiness is under the finger nails. They will almost certainly have been treated with other medicines including steroid creams. Unfortunately this stops the itching but has no affect on the mites.
The patches of skin are usually teeming with mites and any patient with this form of the infection needs to be nursed very carefully as it is highly contagious. Their environment, clothing and bed linen also need special attention.
Anyone in contact with patients with crusted scabies if they were to catch the disease would develop normal/classical scabies.
Why is it called Norwegian scabies?
It should be known as crusted scabies but historically it is often written as Norwegian scabies because the first recorded cases were documented in Norway in 1852, amongst a colony of patients who were also suffering from leprosy.
The people who are most at risk of developing this form of scabies are the very young, and the very old, the former having an immature immune system and the latter one which may be beginning to break down, those who are immune-compromised for any reason perhaps because they are taking immune-suppressing drugs, AIDS/HIV sufferers and those with Down's Syndrome.