Scabies is a highly infectious skin condition which is caused by tiny insects (mites) that access the skin, leading to an itchy skin rash. It takes up to 8 weeks before the symptoms show and it is easy to spread to other people, usually via direct contact.
It is also transmitted as a result of having sex with someone with is already infected: and from sharing bedding, towels and clothing with an infected person. But personal contact with an infected person is the most common way of contracting this disease.
Who is most likely to get scabies?
It is more widespread in densely populated countries with barely adequate healthcare or where it is difficult to obtain medical care. This includes Africa, India and other tropical/sub-tropical areas of the world.
But scabies can develop in the developing world, for example, the UK. It occurs in schools, nurseries and care homes where large numbers of vulnerable people are gathered together in a small space. This makes it easy for the infection to spread.
These cases occur in the winter and in urban areas. The reason for this is bad weather forces people indoors where they are in close proximity to each other.
There are groups of people who are at high risk of catching scabies. These include:
- Elderly people especially those in nursing homes
- Mothers with young children
- People with an active sex life
What is a scabies insect?
This is often referred to as the scabies mite: it is a tiny insect, usually a female, which burrows into the skin and then mates with a male. The female lays eggs which hatch out after 4 days and the cycle begins again.
The end result is a large group of mites which then infect the skin. The itchiness is a reaction from your immune system to the mites and their eggs plus waste products which they deposit in your skin. These mites leave a silvery trail and small red marks on your skin which is evidence of their burrowing into your skin.
How are these mites spread to other people? They cannot jump to another person but can be transmitted if the infected person touches or has prolonged contact with another.
Symptoms of scabies
There are 2 symptoms: itching followed by a skin rash. Itching can take up to 6 weeks to develop which is due to the length of time the body’s immune system takes to react to the infestation.
The skin rash consists of small red spots which turn into crusty sores if scratched.
The scabies rash develops in moist areas of the body such as folds of skin. These include the armpits, underneath the breasts, between the fingers or toes and around the genitals and buttocks. But it may develop on the ankles, inside the elbows, lower legs, knees and the soles of the feet.
Young children, the elderly and people with a weak immune system may develop spots on their neck and face. This is due to the pattern of behaviour from the scabies mites which burrow into different areas of skin. This only occurs with these 3 groups.
If you suspect you might have scabies then visit your GP. It is important to do this in order to prevent this from spreading to other people. Also visit your GP if a close family member has scabies.
Your GP will examine your skin and will make a diagnosis from looking at the areas affected by this rash. But you may be referred for tests to rule out similar skin infections such as impetigo.
One test which is often carried out is the ink test. This is where a small amount of ink is applied to an area of skin rash before being wiped clean with a soft pad. If you have scabies then signs of these mites and their burrowing into your skin will display as a dark line.
Another option is a skin biopsy where a small sample of skin is taken from the infected area and examined under a microscope.
Treatment for scabies
Scabies is treated with creams. There are 2 types of creams which are:
- Malathion lotions
- Permethrin creams
- Calamine lotion
Permethrin creams are prescribed to start with but if they fail then malathion is given. Both of these contain insecticides which kill scabies mites. Calamine lotion and antihistamines will take care of the itching.
Pregnant women and young children must use permethrin cream under medical supervision. Your GP will advise you about this. Malathion lotions are safe to use by children and pregnant women but check first with your GP or pharmacist.
Follow the instructions carefully when applying the cream or lotion.
If there is no improvement after 2 weeks then see your GP. Do this if the rash is clearing or there are signs of new burrows in your skin.
Preventing the spread of the infection
Scabies is contagious so take steps to stop it from spreading any further. Use a separate set of bedding, towels and sheets, and clothes, and wash these on a daily basis.
Wash all these items the first time you start your treatment, e.g. apply the cream or lotion.
Avoid direct contact with other people and anyone else who has this infection.
Children and adults can return to school/work after the first course of treatment.