scabies
2-minute consultation reviewed by a UK clinician
We check your answers and recommend a suitable option
Plain packaging to your door, fast and confidential
Scabies: Symptoms, Treatment and Why It Comes Back
An allergic reaction to a mite, which is why the itch starts late and outlasts the cure — and why treating one person on their own never works.
Key fact: Treating one person does not work. Everyone in the household must be treated at the same time, whether or not they itch, along with anyone you have had close or sexual contact with in the past 8 weeks — because it takes up to 8 weeks for the rash to appear, and untreated contacts pass it straight back.
What scabies is
Scabies is an infestation of the skin by a microscopic mite, Sarcoptes scabiei. The female mite burrows into the outer layer of skin and lays eggs there. The intense itch is not caused by the burrowing itself but by an allergic reaction to the mites, their eggs and their droppings — which is why the itch takes weeks to start and weeks to stop.
It is common, it is nothing to do with cleanliness, and in a typical case there may be only ten to fifteen mites on the whole body.
Symptoms
- Intense itching, markedly worse at night — the single most characteristic feature, and the one that wakes people
- A raised rash or spots, often widespread and out of proportion to the number of mites
- Burrows — fine, slightly raised, greyish wavy lines a few millimetres long, classically in the finger webs and at the wrists. Hard to see, and often scratched away
- Scratch marks, scabs and broken skin, which can become infected
- Others in the household itching too, often starting at different times
Where the rash appears
The distribution is distinctive and is often more useful than the rash itself.
| Typically affected | Usually spared |
|---|---|
| Between the fingers and at the wrists | Head and neck in adults |
| Elbows and armpits | The back, usually less affected |
| Around the waist, navel and buttocks | — |
| Groin and genitals, and around the nipples | — |
| Soles and palms in babies | — |
The exception worth knowing: in babies and very young children, in older adults, and in anyone immunosuppressed, the face, neck, scalp and ears can be involved — which changes where the treatment has to be applied.
How it spreads
- Prolonged, direct skin-to-skin contact — not a handshake or a hug in passing, but sustained contact of the kind that happens in households and in bed
- Sexual contact, which is why partners from the past 8 weeks are treated
- Occasionally via bedding, clothing or towels shared immediately, since mites survive a day or two off a person
- Not from pets — animal mites cannot complete their life cycle on humans
- Not about hygiene — washing more often makes no difference to catching it
Why it takes so long to show
The symptoms are an allergic response, and the immune system takes time to become sensitised. It can be up to 8 weeks before the rash and itch appear after a first infestation. In someone who has had scabies before, the reaction starts within a day or two, because the sensitisation is already there.
Two practical consequences follow, and they explain most treatment failures:
- Contacts can be infested and symptom-free, which is why they are treated regardless
- The itch persisting after treatment is expected, because the allergic reaction outlasts the mites
Treatment
| Permethrin 5% cream | Malathion 0.5% aqueous | |
|---|---|---|
| Position | First line | Second line — where permethrin is unsuitable or has not worked. Available as Derbac-M |
| Where applied | Whole body from the jaw down; also face, neck, scalp and ears in children under 2, older adults and the immunosuppressed | Whole body including face, neck, scalp and ears |
| Left on for | 8 to 12 hours | 24 hours |
| Applications | Two, seven days apart — for both | |
Applied to cool, dry skin, and reapplied to the hands if they are washed during the treatment period. Scabies treatment, step by step covers the application properly, because this is where most courses fail.
Who else needs treating
Everyone in the household, all close contacts, and all sexual contacts from the past 8 weeks — treated on the same day, whether or not they have symptoms. This is not a precaution; it is the treatment. Treating one person while an unaffected-looking household member carries mites simply moves the infestation around and back again.
Bedding and clothing
Unlike head lice, environmental measures do matter here, though only briefly. On the day of the first treatment:
- Wash bedding, towels and clothing at 60°C or hotter, and tumble dry hot where possible
- Anything that cannot be washed hot can be dry-cleaned, or sealed in a plastic bag for at least 72 hours
- Vacuum mattresses and soft furnishings as a reasonable measure
- Do it once, on the day of treatment — and again on the day of the second application. It does not need repeating daily
The itch afterwards
Itching commonly continues for two to four weeks after successful treatment, and occasionally longer. The mites are dead; the allergic reaction is still resolving.
Do not keep re-treating because of itch alone. Repeated applications irritate the skin, which causes more itch, which prompts more treatment. Still itching after scabies treatment covers how to tell persistent allergy from genuine treatment failure.
School and work
- Adults and children aged 5 and over can return to work or school as soon as treatment has started
- Children under 5 can return to nursery or pre-school 24 hours after the first treatment
- Tell close contacts, which is the step that actually limits spread
- Institutional outbreaks — care homes, hostels — are managed differently and need public health input
Crusted scabies
Crusted scabies — sometimes called Norwegian scabies — is a hyper-infestation with thousands to millions of mites, occurring in people whose immune response is impaired. It produces thick, crusted, scaly plaques and can itch surprisingly little. It is extremely contagious, spreads through brief contact and contaminated surfaces, and needs specialist management with combined topical treatment and oral ivermectin. Anyone with widespread crusting and scaling, particularly if immunosuppressed, elderly or in institutional care, needs assessment rather than an over-the-counter cream.
See someone rather than self-treating if: the skin is broken, weeping, crusted or has golden crusts, which suggests impetigo on top and needs treating too; the person is under 2 months old; you are pregnant or breastfeeding; there is widespread crusting or scaling; the immune system is weakened; or two full, correctly applied courses have not worked.
Frequently Asked Questions
How do you know if it is scabies?
The most characteristic feature is intense itching that is markedly worse at night, with a raised rash affecting the finger webs, wrists, elbows, armpits, waist, buttocks, groin and around the nipples, but usually sparing the head and neck in adults. Other people in the household itching too is a strong clue.
How long does it take for scabies symptoms to appear?
It can take up to 8 weeks for the rash to appear after a first infestation, because the itch is an allergic reaction that takes time to develop. In someone who has had scabies before, symptoms start within a day or two. This is why contacts are treated even when they have no symptoms.
Does everyone in the house need treating for scabies?
Yes. Everyone in the household, all close contacts and all sexual contacts from the past 8 weeks should be treated on the same day, whether or not they have symptoms. Treating one person while an untreated contact still carries mites simply moves the infestation around and back again.
How many scabies treatments do you need?
Two, applied seven days apart. Permethrin 5% cream is first line, left on for 8 to 12 hours; malathion 0.5% aqueous liquid is the alternative, left on for 24 hours. Both are applied to the whole body, and the hands are re-treated if washed during the treatment period.
Why am I still itching after scabies treatment?
Because the itch is an allergic reaction to the mites rather than the mites themselves, and it commonly continues for two to four weeks after successful treatment. Repeated re-treatment for itch alone irritates the skin and makes the itching worse rather than better.
Can you get scabies from a pet?
No. Animal mites cannot complete their life cycle on humans, so scabies is not caught from pets. It spreads through prolonged direct skin-to-skin contact, including sexual contact, and occasionally through recently shared bedding, towels or clothing.
References
- NHS. Scabies. nhs.uk
- National Institute for Health and Care Excellence. Clinical Knowledge Summary: Scabies. cks.nice.org.uk
- Nottinghamshire Area Prescribing Committee. Scabies: guidance for primary care. nottsapc.nhs.uk
- IUSTI. European guideline for the management of scabies. iusti.org
- UK Health Security Agency. Health protection in children and young people settings, including education. gov.uk
Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. Scabies treatment must be applied to the whole body and repeated after 7 days, and everyone in the household needs treating at the same time. Always read the leaflet supplied with your own product. Always consult a qualified healthcare professional for diagnosis and treatment. In a medical emergency, call 999.
