Do I have scabies? Symptoms and treatments explained
If you’ve ever had scabies, you’ll know how frustrating and uncomfortable this itchy skin disease can be to live with. It’s been around since at least the Roman period – the word itself comes from the Latin word for ‘to scratch’, which is ‘scabere’. Indeed, scratching is the main symptom of scabies, and it can be so severe that it stops you from getting a good night’s sleep.
Scabies is caused by a mite called Sarcoptes scabiei. These mites are tiny, so it’s unlikely you could see them properly with the naked eye. The female mite is about twice the size of the male, so you may just about be able to see one as a speck (they measure about 0.4 x 0.3mm).
If you have scabies you’ll usually start having symptoms about three or four weeks after coming into contact with an infected person, though they may take up to eight weeks to appear.
The first thing you’ll notice is the itching (pruritus). At first you’ll itch quite severely in one place, such as between the fingers of your hands. Then the itching spreads to other areas of your body (you can itch all over, though not usually on the head). This itching is typically worse at night, which can cause problems with sleeping, and after having a hot bath.
Soon after you start itching you may notice a blotchy red rash that turns into tiny red spots. And while it can spread to any part of the body, the rash most often affects areas such as the inside of the thighs, parts of the abdomen, parts of the buttocks, the ankles and soles of the feet, the armpits and, in women, around the nipples.
In most people the appearance of the rash is typical, but it is possible to have a more unusual-looking rash that could be misdiagnosed as another skin condition.
Meanwhile, all that scratching in response to the itching can make your skin even more irritated and inflamed. It can also lead to skin damage, which in turn may develop into a secondary skin infection if bacteria enter the skin.
How common is it?
Scabies is very common worldwide, with scientists estimating around 300 million people are affected (i). According to the National Institute for Health and Care Excellence (NICE), information from the Health Information Network has suggested that, in the UK, scabies affects 2.81 per 1,000 women and 2.27 per 1,000 men (ii).
As well as being more common in women, scabies is found more often in people aged 10 - 19 and in environments subject to overcrowding and extreme social deprivation. It’s also more common during winter, says NICE. One study also suggests that here in the UK scabies outbreaks can affect places such as residential or nursing homes, hospitals, prisons and – occasionally – schools (iii).
However, as it’s sometimes confused with other skin problems – including eczema, pubic and body lice, psoriasis, folliculitis, seborrheic dermatitis and impetigo – there may be more people affected by scabies than we realise.
How is it spread?
Scabies is spread by close skin contact as the mite can’t jump or fly. You can, for instance, catch it by holding hands with someone who has it. And since it’s thought that skin contact has to last for 10 - 15 minutes before infection can take place, prolonged hand holding is far more likely to cause scabies than shaking hands with someone who has it or giving them a quick hug.
Another typical way of catching scabies is by having sex with an infected person. You may possibly even become infected if you share clothes, bedding or towels with scabies, as the mites can survive away from their human hosts for about 24 - 36 hours – though this is thought to be rare. You can’t, however, catch scabies from pets.
Once on the surface of your skin, a pair of mites mate. The male mite dies, but the female burrows into your skin, laying eggs along the burrow (you may even be able to see the tunnels in your skin as fine, dark or silvery lines that measure about 2 - 10mm in length).
It then takes around 10 - 15 days for the egg to develop into an adult mite, which then returns to the surface of the skin to mate.
What should you do?
If you think you might have scabies, it’s a good idea to see your GP for a proper diagnosis. Scabies is usually diagnosed visually, as the rash is fairly typical. Another tell-tale sign of scabies is a mite tunnel on the skin. Doctors sometimes detect mite tunnels by rubbing ink on the skin and then wiping it off. If there are any burrows in that area, the ink will have moved through the tunnel, which then shows up as a dark line.
You may, however, already be able to see some mite tunnels yourself. If that’s the case, you probably don’t need to see a doctor, as scabies treatments are available over the counter at pharmacies.
While someone with classical scabies is thought to have an average of 10 - 12 mites, a more severe form of the infection can generate thousands or even millions of mites. This is called crusted scabies (or sometimes Norwegian scabies), and, as a result of the far greater number of mites involved, is extremely contagious and far more difficult to treat successfully.
Crusted scabies looks a bit like psoriasis as it causes severe skin scaling and flaking. Areas that are commonly affected can include the hands, feet, scalp, ears and nails – but any part of the skin, including the head or neck, can be covered with a crusting rash.
Crusted scabies can be spread through skin-to-skin contact. But because the mites can survive away from their host for longer (up to a few days), crusted scabies can be much more easily spread through contact with towels, clothes, bedding and upholstery.
Who’s at risk?
Thankfully crusted scabies isn’t common, but it can affect people with immune system problems, such as people with HIV, leukaemia or lymphoma.
Frail people – such as the elderly or those who are unwell with another condition – are also more at risk of having crusted scabies, as are people who are malnourished and those with nerve-related problems.
However, if you’re healthy and you have a normal immune system, you’d usually only develop the ‘normal’ form of scabies after coming into contact with someone with crusted scabies.
If you don’t treat scabies the mites can live in your skin indefinitely. Treating the infestation, however, isn’t usually difficult. But if you have scabies, you, your family and anyone who lives with you should also be treated on the same day. Anyone else you’ve had close contact with, such as sexual partners, should be treated at the same time too – even if they don’t have any symptoms. That’s because they may still be infected and could pass scabies on to someone else before their symptoms start to appear.
There are two main treatments used for scabies, both of which are available over the counter at pharmacies:
Permethrin cream is an insecticide that’s widely thought to be the best scabies treatment at killing mites.
Malathion lotion is also a scabies treatment, but is only usually given when someone can’t use permethrin cream (for instance, if they have an allergy to it).
Both treatments have to be applied to the whole body, including the scalp, face, neck, ears, genitals, soles of the feet and under the nails. The cream or lotion should be left overnight – but not after a hot bath – and then reapplied a week later (permethrin cream should be left on for 8 - 12 hours and malathion lotion for 24 hours). Each top-to-toe application should use 30g of cream or 100ml of lotion for the average adult.
However, if you have crusted scabies, you may need two or three applications of cream or lotion on two or three consecutive days, as one application may not be enough to penetrate any skin that has become crusted. A tablet-based treatment is also used to treat crusted scabies, though this isn’t available over the counter.
Other treatments used for scabies include an insecticide cream or lotion that may help with itching called crotamiton, and hydrocortisone cream, which may help ease inflammation and itching. If you’re having problems sleeping at night because of itching, some types of antihistamine medicine such as chlorphenamine may help, as they can make you drowsy enough to nod off.
As well as treatment, there are some other things you should do to make sure your treatment is successful, including:
Washing all affected clothes, towels and bed linen at 50ºC or higher to kill the scabies mites.
Anything that can’t be washed should be sealed in a plastic bag for at least a week, as this too can kill the mites (alternatively you can put the bag in the freezer).
Another way of killing mites on clothes and other items made of fabric is to iron them at a hot temperature or putting them in a tumble dryer on a hot cycle for 30 minutes.
Avoid having sex or close physical contact until your treatment is complete. Adults can go back to work and children can go back to school 24 hours after the first treatment.
These treatments usually kill scabies mites quickly. But you may continue to itch for a few weeks as it takes time for your skin to settle down. If you still have the itch three weeks after treatment, see your GP, as you may need another treatment with a different insecticide.
Natural support for scabies
Many natural health practitioners recommend various drug-free remedies to help soothe the symptoms of scabies while having medical treatment to kill the mites. One that has attracted the attention of researchers is tea tree oil, which contains antimicrobial substances called terpenoids that may help skin affected by scabies to heal.
One study by Australian researchers found using tea tree oil reduced the survival times of mites collected from a volunteer (iv). Another suggests tea tree oil may even be better at treating scabies than conventional treatments such as permethrin (v).
Meanwhile, since people with impaired immune systems are affected more severely by scabies, it may also be a good idea to make sure your immune system is as strong and healthy as possible. Getting plenty of sleep, avoiding stress, eating a healthy diet and taking regular moderate exercise can help keep your immune system in good working order. You may also want to try a nutritional supplement, such as one of the following:
Experts believe live bacteria – also called ‘friendly’ bacteria – may help regulate and support the immune system (vi). These live bacteria are thought to help restore the natural balance of bacteria in your gut. Live bacteria are available in supplement form, but you could also add more of these foods and drinks to your diet, such as sauerkraut, live yoghurt, kefir and kombucha.
Vitamins B and C
Both of these vitamins support the normal functioning of the immune system. But despite the fact that they’re found in a wide range of everyday foods, many of us may be running short. To make sure you’re getting the level of the B and C vitamins your immune system needs, you may want to consider taking a high-quality B complex supplement as well as a high-quality vitamin C supplement. You can also get both nutrients in good levels in a quality multivitamin and mineral formulation.
High-strength multivitamin and mineral
As well as having a healthy diet, taking a high-strength multivitamin and mineral supplement may help make sure your immune system is getting all the nutrients it needs to stay as strong and effective as possible, especially when dealing with infections. For the best results, a multivitamin and mineral supplement should include good levels of zinc, which is thought to be important for immune function (vii) as well as vitamin D (viii).
Another supplement that may be useful for immune health is elderberry extract as it contains powerful antioxidants called anthocyanins. There is also evidence to suggest black elderberry extract increases the body’s production of chemical messengers within the immune system called cytokines, suggesting it has an immune-supporting function (ix).
Gunning, K., Pippitt, K., Kiraly, B., et al. Pediculosis and scabies: treatment update. Am Fam Physician. (2012 Sep). ;1586(6):535-41. Available online: https://www.aafp.org/afp/2012/0915/p535.html
National Institute for Health and Care Excellence. Scabies prevalence. Available online: https://cks.nice.org.uk/scabies#!backgroundsub:1
Hewitt, K.A., Nalabanda, A., Cassell, J.A. Scabies outbreaks in residential care homes: factors associated with late recognition, burden and impact. A mixed methods study in England. Epidemiol Infect. (2014 Sep). ;8:1-10. Available online: https://www.ncbi.nlm.nih.gov/pubmed/25195595?dopt=Abstract
Walton, S.F., et al. Acaricidal activity of Melaleuca alternifolia (tea tree) oil: in vitro sensitivity of sarcoptes scabiei var hominis to terpinen-4-ol. Arch Dermatol. (2004 May). ;140(5):563-6. Available online: https://www.ncbi.nlm.nih.gov/pubmed/15148100
Thomas, J, et al. Therapeutic Potential of Tea Tree Oil for Scabies. Am J Trop Med Hyg. (2016 Feb). 3; 94(2): 258–266. Available online: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4751955
Yah, F., Polk, D.B.. Probiotics and immune health. Curr Opin Gastroenterol. (2011 Oct). ;27(6): 496–501. Available online: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4006993
Chiang, B.L., Sheih, Y.H., Wang, L.H., et al. Enhancing immunity by dietary consumption of a probiotic lactic acid bacterium (Bifidobacterium lactis HN019): optimization and definition of cellular immune responses. Eur J Clin Nutr. (2000). ;54:849-855. Available online: https://www.ncbi.nlm.nih.gov/pubmed/11114680
Chandra, R.K. Trace element regulation of immunity and infection. J Am Coll Nutr. (1985). ;4:5-16.
Fraker, P.J., Gershwin, M.E., Good, R.A., et al. Interrelationships between zinc and immune function. Fed Proc. (1986). ;45:1474-1479. Available online: https://www.sciencedirect.com/science/article/pii/S0271531782801164
Aranow, C. Vitamin D and the Immune System. J Investig Med. (2011 Aug). 59(6):881-886. Available online: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3166406
Barak, V., Halerpin, T., Kalickman, I. (2015). The effect of Sambucol, a black elderberry-based, natural product, on the production of human cytokines: I. Inflammatory cytokines. Eur Cytokine Netw. (2001 Apr-Jun). ;12(2):290-6. Available online: https://www.ncbi.nlm.nih.gov/pubmed/11399518