Scabies (pediatric) in Child
See also in: AnogenitalAlerts and Notices
Synopsis
Scabies is a parasitic infestation of the epidermis. It is caused by the obligate human parasite Sarcoptes scabiei var hominis and is transmitted via direct skin-to-skin contact (usually 10-20 minutes' contact) and rarely by fomites such as bedding and clothing. Scabies affects all ethnic groups and socioeconomic levels. Scabies is most common in young children, and the highest prevalence is seen in children younger than 2 years. It is extremely contagious, spreading between individuals who share close contact or living spaces. Frequent outbreaks occur in schools, group homes, and orphanages where direct contact with infested individuals is common. The most common predisposing factors are overcrowding, poverty, poor nutrition, and being undomiciled. Other predisposing conditions include immunocompromised status, HIV infection, and severe intellectual or physical disability. The highest prevalence of infestation is seen in tropical regions such as Central America, the Northern Territory of Australia, and the Pacific Islands.
Infestation begins with the female mite, which burrows within the stratum corneum of the host and lays its eggs. The eggs develop into larvae, nymphs, and adults. The average number of adult female mites in an infested individual is 10-15, but this number can be much larger in those who are immunocompromised. If separated from human hosts, the mite can survive at most a few days. Symptoms and signs typically develop approximately 3 weeks after the primary infestation.
Clinically, scabies infestation manifests in 3 ways: classic, nodular, or crusted (previously called Norwegian scabies).
- Classic scabies in children presents with pruritic papules affecting flexural areas, including the axillary folds, wrists, and dorsal ankles; the interdigital web spaces of the hands and feet; anogenital area; and truncal areas, especially around the nipples and periumbilical areas (the circle of Hebra). It is accompanied by itch, which is classically worse at night, especially just after getting into bed.
- Nodular scabies, a clinical variant of classic scabies, is less common in children than in adults. It is considered a hypersensitivity reaction to the mite and manifests with erythematous nodules.
- The crusted variant of scabies is most common in individuals who are immunocompromised. It presents with widespread scaly, crusted, or hyperkeratotic papules and plaques. Scales may have a powdery texture. Pruritus may be severe but is usually minimal or absent. Nail dystrophy can be present. It is extremely contagious due to the high mite burden; there may be up to a million mites on a single individual.
Codes
ICD10CM:B86 – Scabies
SNOMEDCT:
128869009 – Infestation by Sarcoptes scabiei var hominis
Look For
Subscription Required
Diagnostic Pearls
Subscription Required
Differential Diagnosis & Pitfalls
- Papular urticaria – A hypersensitivity reaction to a variety of bites, such as mosquitoes, fleas, bedbugs, and mites. There may be a seasonal occurrence. Recurrent episodes of excoriated papular and urticarial lesions on the exposed parts of the extremities (extensor aspect) are the cardinal features. Absence of burrows and family history of itching differentiate this from scabies.
- Atopic dermatitis – Eczematous lesions with oozing on the face and flexural areas (cubital and popliteal fossa). Lichenification is seen in chronic dermatitis. Burrows are absent, and lesions are not seen in the web spaces.
- Impetigo – Erythematous vesiculopustular lesions that rupture, forming the pathognomonic honey-colored crust. Lesions may involve the face, neck, and extremities. Scabies may sometimes be impetiginized, so a good history may distinguish primary versus secondary impetigo.
- Folliculitis
- Nummular dermatitis
- Langerhans cell histiocytosis
- Insect bites
- Tinea corporis
- Dermatitis herpetiformis
- Eczema herpeticum
- Pityriasis rosea
- Viral exanthems
- Prurigo nodularis
- Leukemia or lymphoma cutis
Best Tests
Subscription Required
Management Pearls
Subscription Required
Therapy
Subscription Required
References
Subscription Required
Last Reviewed:02/15/2023
Last Updated:04/06/2023
Last Updated:04/06/2023
Patient Information for Scabies (pediatric) in Child
Overview
Scabies is an itchy skin condition caused by a tiny mite called Sarcoptes scabiei that can live and multiply on skin. Scabies is not an "infection;" it is an "infestation," but the two words tend to be used interchangeably when discussing scabies. Scabies is passed between people by prolonged skin-to-skin contact. Scabies is extremely contagious and spreads rapidly in crowded conditions such as hospitals, nursing homes, child-care facilities, and other situations where people spend extended periods of time in close contact with each other.The itchy rash of scabies develops when a pregnant female mite burrows into the outer surface (superficial) skin and lays eggs. The human immune system is highly sensitive to the presence of the mite and produces a massive allergic response, which causes intense itching. Although a typical infection includes only 10–20 mites, people are so sensitive to the mite that hundreds of itchy skin lesions are created. Without treatment, the condition will not usually improve.
Who’s At Risk
Scabies is seen in people of all races, of all ages, and of both sexes.Scabies is not caused by lack of personal hygiene, though it is more frequently seen in people who live in crowded conditions.
Other individuals at risk include:
- Children
- Mothers of young children
- Sexually active young adults
- People living in nursing homes
- Nursing home staff
Signs & Symptoms
Although the entire body may itch, the most common locations for the lesions of scabies in older children and adults include:- The areas between the fingers (finger webs)
- Inner wrists, inner elbows, and armpits
- Breasts of females and genitalia of males
- Navel (umbilicus)
- Lower abdomen
- Buttocks
- Backs of knees
- Trunk, arms, and legs
- Head and neck
- Palms of the hands and soles of the feet
Scabies is intensely itchy, especially at night.
Scratching the itchy lesions can create breaks in the skin, and these breaks can become infected with bacteria.
People who are exposed to scabies may not develop itchy lesions for up to 6 weeks after becoming infested, as the immune system takes some time to recognize the mites and develop an allergic response to them. However, individuals who have had scabies before may develop the rash within several days of re-exposure.
Self-Care Guidelines
Though scabies is extremely contagious, it usually requires prolonged skin-to-skin contact with a person already infested. A quick handshake or hug will not normally spread the infection. However, scabies is easily spread to sexual partners and to other members of the household. Less commonly, it may be spread by sharing towels, clothing, or bedding.Scabies requires prescription medication in order to stop the infestation. Once your child is under a doctor's care, there are steps you can take to prevent scabies from coming back:
- Mites cannot survive off the human body for more than 48-71 hours. Therefore, wash all clothing, bedding, and towels used by the infested person in the previous 72 hours in hot water and dry these items in a hot dryer.
- Vacuum all carpets, rugs, and upholstered furniture, and discard the vacuum bags.
When to Seek Medical Care
See your child's doctor for evaluation if he or she develops an extremely itchy rash. If other members of the household or your child's close contacts have similar itchy rashes, make sure they are also evaluated by a physician.Treatments
The physician may be able to diagnose scabies simply by examining your child's skin for typical lesions such as burrows. A skin scraping, called a scabies preparation, may be examined under the microscope for mites, eggs, or mite droppings (feces).In most cases of scabies, the doctor may recommend a topical cream or lotion, such as:
- Permethrin cream – Apply at night, and rinse off in the morning. Use the permethrin cream again in 1 week.
- Crotamiton cream – Apply once daily for 2 consecutive days, and rinse off 48 hours after last application.
- Sulfur ointment – Apply nightly for 3 consecutive nights, and rinse off 24 hours after last application. This is often the best choice for babies and for pregnant and nursing women because it is very safe to use.
- Lindane lotion or cream – Wash the cream or lotion off after 8 hours. Lindane may be toxic to some people. Infants and young children should not be treated with lindane, nor should pregnant or breast-feeding women or people with diseases affecting the nerves (neurological diseases).
- Apply to the entire body from the neck down.
- Smear the product beneath your child's fingernails and toenails.
- Apply to body folds, including inside the navel, in the buttock crease, and between the toes.
- Ivermectin pills – Take once and then repeat 1–2 weeks later. Ivermectin should not be used for children aged younger than 5 years or who weigh less than 15 kg (about 35 lb), or pregnant or lactating women.
- Antihistamine pill.
- Antibiotic pills – If any scratched areas appear to be infected with bacteria, your physician may prescribe oral antibiotics.
Your doctor should remind you to launder towels, bed linens, and clothes used by your child in the previous 72 hours and to vacuum carpets, rugs, and upholstered furniture.
Household members, sexual partners, and anyone else with prolonged skin-to-skin contact with an infested person should also seek treatment from their doctors. Since the initial development (incubation time) for scabies infestations can be from 6–8 weeks, people may be infected with scabies, but since they do not yet feel itchy, they are unaware that they have infestation. If untreated, these close contacts could pass the mites back to your child. Ideally, everyone should be treated at the same time in order to prevent re-infestation.
References
Bolognia, Jean L., ed. Dermatology, pp.1321-1324. New York: Mosby, 2003.
Freedberg, Irwin M., ed. Fitzpatrick's Dermatology in General Medicine. 6th ed. pp.1374, 2283-2284. New York: McGraw-Hill, 2003.