Changes

September 2025 — minor update. Revised wording on prescribing a second dose of ivermectin after 7 days to enhance effectiveness. 

Update

Goals

To support primary healthcare professionals to:

• Diagnose and manage classical scabies infestation.
• Recognize crusted scabies and refer to secondary care appropriately.

Outcome measures

Audit criteria

QOF indicators

QIPP - Options for local implementation

NICE quality standards

What is it?

• Scabies is an intensely itchy skin infestation caused by the human parasite Sarcoptes scabiei, a 0.3- to 0.5-mm mite that burrows into the epidermis and tunnels through the stratum corneum [Morris, 2025]:
  • The life cycle lasts for 4–6 weeks.
  • The female lays about 25 eggs, then dies.
  • The eggs develop into adults in 10–15 days.
• Classical scabies (typical scabies) involves infestation with a low number of mites (about 5–15 per host) [Salavastru, 2017].
• Crusted scabies (Norwegian scabies) is a hyperinfestation with thousands or millions of mites present in exfoliating scales of skin [NICE, 2014; BMJ, 2022]. It develops as a result of an insufficient immune response by the host.

How common is it?

• Scabies is endemic in some populations (such as in sub-tropical locations and/or developing countries) but may be seen episodically or in epidemics in other populations [BMJ, 2022].
• The prevalence is estimated to be more than 200 million cases worldwide [Arora, 2020; BMJ, 2022]. However, this varies geographically, and in some communities, particularly in sub-tropical and developing countries, prevalence may approach 70% [BMJ, 2022].
• A study using data from The Health Information Network (THIN) examined the epidemiology of scabies consultations in the UK by age, sex, region of the country, and time and [Lassa, 2011] reported that:
  • There was a significantly greater infestation rate among females with a relative risk of 1.24 (p < 0.001) than males.
  • People aged 10–19 years had the highest infestation rates (with rates of 4.55 per 1000 and 5.92 per 1000 for males and females, respectively). Middle-aged people had the lowest infestation rates.
  • A cycle length of between 15–17 years was reported, with phase time cycles for each region suggesting a progression of the disease originating from the North East, spreading to Northern parts of the UK then to the Midlands and the South.

How is scabies transmitted?

• Classical scabies is transmitted through close/prolonged skin contact with an infected person.
  • Scabies is frequently sexually acquired.
  • Transmission through casual contact, such as a handshake, is unlikely.
  • The mites can live away from a host for an average of 24–36 hours, although survival can be prolonged at lower ambient temperature and higher humidity. Transmission via shared clothing or bedding can therefore occur.
  • Symptoms begin 3–6 weeks after primary infestation but occur earlier (at 1–3 days) in a reinfested person, probably due to prior sensitization to the mite and mite products. Scabies is therefore infectious before the rash develops.
• Crusted scabies is highly contagious, and, in addition to transmission by direct contact, is easily transmissible via bedding, towels, clothes, and upholstery due to the large numbers of mites on an infested person.
  • In crusted scabies, the mites can survive away from the host for up to 7 days.
• Rarely, scabies can be transmitted to people from dogs (caused by Sarcoptes scabiei var canis) and cats (caused by Notoedres cati). See the section on Differential diagnosis for more information.

[Chosidow, 2006]  [Salavastru, 2017; BMJ, 2022; Morris, 2025]

What are the risk factors?

• Risk factors for scabies include [NICE, 2014] [BMJ, 2022]: 
  • Close contact with an infested person.
  • High levels of poverty and social deprivation.
  • Crowded living conditions and institutionalization — scabies can occur in outbreaks in nursing homes, long-term care facilities, military barracks, and prisons.
  • Winter months — probably due to increased crowding and prolonged survival of mites away from the host in cooler temperatures.
• Crusted scabies develops as a result of an attenuated immune response by the host.
  • It is primarily seen in [NICE, 2014; BMJ, 2022]: 
    • People with a history of immunosuppression (such as those with HIV or lymphoma, or on long-term corticosteroid treatment).
    • People with a reduced ability to scratch (for example due to physical incapacity or because the itch is not perceived because of skin anaesthesia).
    • People with learning difficulties or neurological disorders (such as dementia or Down's syndrome).
    • Elderly people.

What are the complications and prognosis of scabies?

• Complications of scabies infestation include [Arora, 2020; BMJ, 2022; Morris, 2025]:
  • Secondary bacterial infection — this may result in impetigo, folliculitis, furunculosis, ecthyma, or abscess.
  • Secondary eczematization — this may be due to scratching and/or the irritant effects of topical medication.
  • Nodular scabies — pruritic nodules of the axillae, groin, and male genitalia can persist for weeks or months following treatment due to a prolonged immune response to mite antigens.
• Scabies is generally associated with a good prognosis provided compliance is satisfactory and all close contacts (symptomatic or asymptomatic) are simultaneously treated [BMJ, 2022] [Maguire, 2022]. 
  
  • Most people with scabies are cured after two treatments with topical permethrin. However, itching may continue for up to 4 weeks after successful treatment for scabies.
  • Crusted scabies may need prolonged and repeated treatment, and patients may have significant underlying conditions that will influence the prognosis [Maguire, 2022].

How should I diagnose scabies?

Diagnoses of scabies are usually made from the history and examination of the affected person, and a history from their family and close contacts. Skin scraping microscopy can be used to confirm the diagnosis.

• Take a history. 
  • Ask about itching.
    • The main clinical feature of classical scabies is intense generalized itch that is usually worse at night. The itch is due to a delayed type-IV hypersensitivity reaction to the mite and mite products (faeces and eggs).
    • Symptoms begin 3–6 weeks after primary infestation but occur earlier (at 1–3 days) in a reinfested person, probably due to prior sensitization to the mite and mite products. 
    • Note that the absence of itching does not exclude scabies (for example, in young babies and in people with neurological conditions with decreased/loss of sensation). 
  • Ask about/note:
    • Whether family members/close contacts have also reported itching.
    • The person's living conditions — scabies is associated with overcrowded living conditions and can occur in outbreaks in nursing homes, long-term care facilities, military barracks, and prisons.
    • The person's age and/or age of people with whom they have close contact — children and elderly people may be more susceptible to infestation.
    • Sexual contact with new or multiple partners.
• Examine the person.
  • The most common lesions are erythematous papules disseminated in a characteristic distribution on the periumbilical area, waist, genitalia, breasts, buttocks, axillary folds, fingers (including interdigital spaces), wrists, and extensor aspects of the limbs. 
    • The back is often not involved, and the head is spared, except in children.
    • Palms and soles are also affected in the elderly and in infants and young children.
    • The papules are small and are often excoriated with haemorrhagic crusts on top.
  • The burrow (a pathognomonic sign) appears as a thin, brown-grey line of 0.2–1 cm in length.
    • The burrows are produced by the moving mite and are difficult to observe if the skin has been scratched, has become secondarily infected, or if eczema is present.
  • Nodular lesions may also be seen, especially on the penis and scrotum in men, buttocks, groin, and the axillary regions and these are intensely pruritic. They tend to persist after treatment and are thought to result from a hypersensitivity reaction to the mite.
    • Urticarial lesions may rarely occur.
    • Presence of itchy papules and nodules on the penis and scrotum are indicative of sexually acquired scabies.
• People who are immunocompromised may develop crusted (Norwegian) scabies.
  • Pruritus is mild or absent due to impaired immune response.
  • Skin lesions consist of generalized, poorly defined, erythematous, fissured plaques covered by scales and crusts.
  • On bony prominences (for example, finger articulations, elbows, and iliac crest), the plaques have a yellow-to-brown, thick, verrucous aspect.
  • Diffuse non-crusted scabies with involvement of the back may also occur.
  • Bacterial secondary infection can result in malodorous skin lesions.
• Use clinical judgement to determine if confirmation of the diagnosis with the ink burrow test and/or microscopy of skin scrapings from papules or burrows is required. These methods can provide a definitive diagnosis but should only be carried out in primary care if appropriate equipment and expertise are available.
  • The ink burrow test:
    • Back or blue ink is applied to the suspected papule and then wiped off with alcohol to remove surface ink. If the person has scabies, a dark zigzagged line running across and away from the lesion appears, due to ink tracking down the mite burrow.
  • Microscopy of skin scrapings:
    • Papules or linear lesions are scraped with a number 15 scalpel blade which has been dipped in liquid paraffin. Multiple (four or more) lesions should be scraped from each patient, with scraping sufficient to cause bleeding. 
    • The skin scrapings are then transferred to a slide and viewed under a microscope.
    • The presence of mites, eggs, or mite faecal material confirms the diagnosis.
    • This test is 100% specific if a mite is seen, however, sensitivity is generally less than 50% due to the low number of mites typically found on an infested person.
• Consider differential diagnoses, such as dermatitis, public lice, and insect bites.
  • Rarely, scabies can be transmitted to people from dogs (caused by Sarcoptes scabiei var canis) and cats (caused by Notoedres cati).

What else might it be?

• The differential diagnoses of scabies include:
  • Other infestations, such as:
    
    • Pubic lice — suggested by itchy, red papules in any course body hair. For more information, see the CKS topic on Pubic lice.
    • Body lice — itching is the principal complaint. The body is often covered in excoriations, and there may be secondary bacterial infection.
    • Animal scabies — occasionally infests humans. Pet dogs are the most common source. Compared with infestation with scabies from other humans, the incubation period is shorter, the distribution different (lesions mainly occur in areas that have been in contact with the animal), there are no burrows. The infestation tends to be self-limiting and often requires no treatment.
  • Insect bites — suggested by itchy papules or papulovesicles and absence of linear burrows. For more information, see the CKS topic on Insect bites and stings.
  • Other dermatological conditions, including:
    • Acropustulosis — suggested by a recurrent, self-limited, pruritic, vesiculopustular eruption of the palms and soles, occurring in infants aged 2–3 years.
    • Atopic eczema — suggested by a dry, itchy, red rash that often starts in childhood. For more information, see the CKS topic on Eczema - atopic.
    • Bullous pemphigoid — a blistering disease of elderly people, which often starts with pruritus and an urticaria-like rash, although this may occasionally be eczematous. Later, large, tense blisters develop.
    • Contact dermatitis — suggested by a rash that develops following contact with an allergen/irritant. For more information, see the CKS topic on Dermatitis - contact.
    • Dermatitis herpetiformis — a rare, chronic, recurrent, papulovesicular disease. It is symmetrical and consists of erythematous, urticarial, papular, or vesicular lesions located on the extensor surfaces of the elbows, knees, buttocks, and back. It is extremely itchy, and the vesicles are often excoriated.
    • Folliculitis — suggested by multiple follicular erythematous papules or pustules, most commonly on the chest and back. For more information, see the CKS topic on Boils, carbuncles, and staphylococcal carriage.
    • Grover's disease (acantholytic dermatosis) — this mainly affects the trunk in elderly or middle-aged people and presents as an acute eruption of discrete, itchy, grey-pink papules or papulovesicles and papules. It is of unknown aetiology.
    • Impetigo — suggested by macules which develop into vesicles and form golden yellow crusts. Most often affects exposed areas on the face, hands, and extremities, and is more common in young children. For more information, see the CKS topic on Impetigo.
    • Langerhans cell histiocytosis — this may present with the following: greasy scales on the scalp; discrete, yellow-brown, scaly papules on the trunk often with areas of purpura which may become nodular, crusted, or eroded; ulceration of the flexures, groin, perianal or vulval regions.
    • Lichen planus — suggested by an itchy eruption characterized by shiny bluish-purple, flat-topped, polygonal papules which vary in size from pinpoint to a centimetre across, and may be close together or widely dispersed. 
    • Neurodermatitis (lichen simplex) — suggested by thickening of the skin with variable scaling that arises secondary to repetitive scratching or rubbing. Pruritus is the predominant symptom.
    • Prurigo nodularis — suggested by discrete, nodular, hyperpigmented/purpuric lesions with surfaces that are scaly, excoriated, and possibly crusted, caused by scratching due to intense localized itchiness. Lesions range from small papules to hard globular nodules 1–3 cm in diameter.
    • Seborrhoeic dermatitis — suggested by red, flaky, greasy areas of skin, which are commonly found on the scalp (dandruff), nasolabial folds, eyebrows, behind the ears, and on the upper chest. For more information, see the CKS topic on Seborrhoeic dermatitis.
    • Systemic lupus erythematosus (SLE) — suggested by a discrete maculopapular rash with fine scaling on sun-exposed areas.
    • Urticaria pigmentosa — suggested by numerous reddish-brown or pale, monomorphic maculopapules, plaques, or nodules appearing symmetrically anywhere on the body, except the face, head, palms, or soles.
• The differential diagnoses of crusted scabies include:
  
  • Psoriasis — characterized by red, scaly, sharply-demarcated, indurated plaques, present, particularly over the extensor surfaces and scalp. For more information, see the CKS topic on Psoriasis.
  • Darier's disease (Keratosis follicularis) — characterized by greasy, skin-coloured, brown or yellow-brown, hyperkeratotic papules in seborrhoeic regions, nail abnormalities, and mucous membrane changes. It is an inherited condition (autosomal dominant).
  • Xerotic dermatitis — characterized by symmetric areas of dry skin with diffuse scale that worsens in severity distally.

Scenario: Management of scabies

From age 2 months onwards.

Permethrin cream

Search strategy

Scope of search

A literature search was conducted for guidelines, systematic reviews and randomized controlled trials on primary care management of scabies.

Search dates

November 2017 - April 2022

Key search terms

Various combinations of searches were carried out. The terms listed below are the core search terms that were used for Medline.

• exp Scabies/, exp Sarcoptes scabiei/
• scabies.tw., sarcoptes scabiei.tw. or (classical scabies or crusted scabies).ti,ab.

Sources of guidelines

• National Institute for Health and Care Excellence (NICE)
• Scottish Intercollegiate Guidelines Network (SIGN)
• Royal College of Physicians
• Royal College of General Practitioners
• Royal College of Nursing
• NICE Evidence
• World Health Organization
• Guidelines International Network
• TRIP database
• Agency for Healthcare Research and Quality
• National Health and Medical Research Council (Australia)
• Royal Australian College of General Practitioners
• British Columbia Medical Association
• Canadian Medical Association
• Alberta Medical Association
• Michigan Quality Improvement Consortium
• Singapore Ministry of Health
• National Resource for Infection Control
• RefHELP NHS Lothian Referral Guidelines
• Medline (with guideline filter)
• Driver and Vehicle Licensing Agency
• NHS Health at Work (occupational health practice)

Sources of systematic reviews and meta-analyses

• The Cochrane Library:
  • Systematic reviews
  • Protocols
  • Database of Abstracts of Reviews of Effects
• Medline (with systematic review filter)
• EMBASE (with systematic review filter)

Sources of health technology assessments and economic appraisals

• NIHR Health Technology Assessment programme
• The Cochrane Library:
  • NHS Economic Evaluations
  • Health Technology Assessments
• Canadian Agency for Drugs and Technologies in Health
• International Network of Agencies for Health Technology Assessment

Sources of randomized controlled trials

• The Cochrane Library:
  • Central Register of Controlled Trials
• Medline (with randomized controlled trial filter)
• EMBASE (with randomized controlled trial filter)

Sources of evidence based reviews and evidence summaries

• Drug and Therapeutics Bulletin
• TRIP database
• Central Services Agency COMPASS Therapeutic Notes

Sources of national policy

• Department of Health
• Health Management Information Consortium (HMIC)

Patient experiences

• Healthtalk
• BMJ - Patient Journeys

Sources of medicines information

The following sources are used by CKS pharmacists and are not necessarily searched by CKS information specialists for all topics. Some of these resources are not freely available and require subscriptions to access content.

• British National Formulary (BNF)
• electronic Medicines Compendium (eMC)
• European Medicines Agency (EMEA)
• Medicines and Healthcare products Regulatory Agency (MHRA)
• REPROTOX
• Scottish Medicines Consortium
• Stockley's Drug Interactions
• TERIS
• TOXBASE
• Micromedex
• UK Medicines Information

Stakeholder engagement

Our policy

The external review process is an essential part of CKS topic development. Consultation with a wide range of stakeholders provides quality assurance of the topic in terms of:

• Clinical accuracy.
• Consistency with other providers of clinical knowledge for primary care.
• Accuracy of implementation of national guidance (in particular NICE guidelines).
• Usability.

Principles of the consultation process

• The process is inclusive and any individual may participate.
• To participate, an individual must declare whether they have any competing interests or not. If they do not declare whether or not they have competing interests, their comments will not be considered.
• Comments received after the deadline will be considered, but they may not be acted upon before the clinical topic is issued onto the website.
• Comments are accepted in any format that is convenient to the reviewer, although an electronic format is encouraged.
• External reviewers are not paid for commenting on the draft topics.
• Discussion with an individual or an organization about the CKS response to their comments is only undertaken in exceptional circumstances (at the discretion of the Clinical Editor or Editorial Steering Group).
• All reviewers are thanked and offered a letter acknowledging their contribution for the purposes of appraisal/revalidation.
• All reviewers are invited to be acknowledged on the website. All reviewers are given the opportunity to feedback about the external review process, enabling improvements to be made where appropriate.

Stakeholders

• Key stakeholders identified by the CKS team are invited to comment on draft CKS topics. Individuals and organizations can also register an interest to feedback on a specific topic, or topics in a particular clinical area, through the Getting involved section of the Clarity Informatics website.
• Stakeholders identified from the following groups are invited to review draft topics:
  • Experts in the topic area.
  • Professional organizations and societies (for example, Royal Colleges).
  • Patient organizations, Clarity has established close links with groups such as Age UK and the Alzheimer’s Society specifically for their input into new topic development, review of current topic content and advice on relevant areas of expert knowledge.
  • Guideline development groups where the topic is an implementation of a guideline.
  • The British National Formulary team.
  • The editorial team that develop MeReC Publications.
• Reviewers are provided with clear instructions about what to review, what comments are particularly helpful, how to submit comments, and declaring interests.

Patient engagement

Clarity Informatics has enlisted the support and involvement of patients and lay persons at all stages in the process of creating the content which include:

• Topic selection
• Scoping of topic
• Selection of clinical scenarios
• First draft internal review
• Second draft internal review
• External review
• Final draft and pre-publication

Our lay and patient involvement includes membership on the editorial steering group, contacting expert patient groups, organizations and individuals.

Evidence exclusion criteria

Our policy

Scoping a literature search, and reviewing the evidence for CKS is a methodical and systematic process that is carried out by the lead clinical author for each topic. Relevant evidence is gathered in order that the clinical author can make fully informed decisions and recommendations. It is important to note that some evidence may be excluded for a variety of reasons. These reasons may be applied across all CKS topics or may be specific to a given topic.

Studies identified during literature searches are reviewed to identify the most appropriate information to author a CKS topic, ensuring any recommendations are based on the best evidence. We use the principles of the GRADE and PICOT approaches to assess the quality of published research. We use the principles of AGREE II to assess the quality of published guidelines.

Standard exclusions for scoping literature:

• Animal studies
• Original research is not written in English

Possible exclusions for reviewed literature:

• Sample size too small or study underpowered
• Bias evident or promotional literature
• Population not relevant
• Intervention/treatment not relevant
• Outcomes not relevant
• Outcomes have no clear evidence of clinical effectiveness
• Setting not relevant
• Not relevant to UK
• Incorrect study type
• Review article
• Duplicate reference

Organizational, behavioural and financial barriers

Our policy

The CKS literature searches take into consideration the following concepts, which are discussed at the initial scoping of the topic.

• Feasibility
  • Studies are selected depending on whether the intervention under investigation is available in the NHS and can be practically and safely undertaken in primary care.
• Organizational and Financial Impact Analysis
• Studies are selected and evaluated on whether the intervention under investigations may have an impact on local clinical service provision or national impact on cost for the NHS. The principles of clinical budget impact analysis are adhered to, evaluated and recorded by the author. The following factors are considered when making this assessment and analysis.
  • Eligible population
  • Current interventions
  • Likely uptake of new intervention or recommendation
  • Cost of the current or new intervention mix
  • Impact on other costs
  • Condition-related costs
  • In-direct costs and service impacts
  • Time dependencies
• Cost-effectiveness or cost-benefit analysis studies are identified where available. 

We also evaluate and include evidence from NICE accredited sources which provide economic evaluations of recommendations, such as NICE guidelines. When a recommended action may not be possible because of resource constraints, this is explicitly indicated to healthcare professionals by the wording of the CKS recommendation.

Declarations of interest

Our policy

Clarity Informatics requests that all those involved in the writing and reviewing of topics, and those involved in the external review process to declare any competing interests. Signed copies are securely held by Clarity Informatics and are available on request with the permission of the individual. A copy of the declaration of interest form which participants are asked to complete annually is also available on request. A brief outline of the declarations of interest policy is described here and full details of the policy is available on the Clarity Informatics website. Declarations of interests of the authors are not routinely published, however competing interests of all those involved in the topic update or development are listed below. Competing interests include:

• Personal financial interests
• Personal family interest
• Personal non-financial interest
• Non-personal financial gain or benefit

Although particular attention is given to interests that could result in financial gains or losses for the individual, competing interests may also arise from academic competition or for political, personal, religious, and reputational reasons. An individual is not obliged to seek out knowledge of work done for, or on behalf of, the healthcare industry within the departments for which they are responsible if they would not normally expect to be informed.

Who should declare competing interests?

Any individual (or organization) involved in developing, reviewing, or commenting on clinical content, particularly the recommendations should declare competing interests. This includes the authoring team members, expert advisers, external reviewers of draft topics, individuals providing feedback on published topics, and Editorial Steering Group members. Declarations of interest are completed annually for authoring team and editorial steering group members, and are completed at the start of the topic update and development process for external stakeholders.

Competing interests declared for this topic:

None.