Crusted Scabies Cases (Single or Multiple)

Local and/or state health departments may be able to provide guidelines for preventing and controlling scabies outbreaks.

Below are suggestions for developing guidelines for preventing, detecting, and responding to a single case or multiple cases of crusted (Norwegian) scabies in an institution.


Establish surveillance.

  • Have an active program for early detection of infested patients and staff; unrecognized crusted scabies is frequently the source of institutional scabies outbreaks.
  • Maintain a high index of suspicion that scabies may be the cause of undiagnosed skin rash; suspected cases should be evaluated and confirmed by obtaining skin scrapings; persons with crusted scabies may not show the characteristic symptoms of scabies such as rash and itching (pruritus).
  • Screen all new patients and staff for scabies.
  • Notify the local health department; notify other institutions to or from which infested or exposed patients may have transferred.
  • Maintain ongoing surveillance for scabies among all patients and staff to identify new or unsuccessfully treated cases of scabies.

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Diagnostic Services

Ensure that adequate diagnostic services are available.

  • Consult with an experienced dermatologist for assistance in differentiating skin rashes and confirming the diagnosis of scabies.
  • Ensure someone on-staff is trained and experienced in obtaining and examining a skin scraping to identify scabies mites.

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Control & Treatment

Establish appropriate procedures for infection control and treatment.

  • Remember that persons with crusted scabies are infested with very large numbers of mites; this increases the risk of transmission both from brief skin-to-skin contact and from contact with items such as bedding, clothing, furniture, rugs, carpeting, floors, and other fomites that can become contaminated with skin scales and crusts shed by a person with crusted scabies.
  • Maintain records with patient name, age, sex, room number, roommate(s) name(s), skin scraping status and result(s), and name(s) of all staff who provided hands-on care to the patient before implementation of infection control measures: symptoms can take up to 2 months to appear in exposed persons and staff.
  • Use epidemiologic data about distribution of confirmed cases by building, room, floor, wing, occupation (for staff), dates of admission, and onset of scabies-like condition to determine: 1) levels of risk for patients, staff, and visitors; 2) extent of the outbreak (e.g. confined or widespread in the facility; and 3) temporal relationship among cases.
  • Use contact precautions with protective garments (e.g. gowns, disposable gloves, shoe covers, etc.) when providing care to any patient with crusted scabies until successfully treated; wash hands thoroughly after providing care to any patient.
  • Isolate patients with crusted scabies from other patients who do not have crusted scabies; consider assigning a cohort of caretakers to care only for patients with crusted scabies.
  • Maintain contact precautions until skin scrapings from a patient with crusted scabies are negative; persons with crusted scabies generally must be treated at least twice, a week apart; oral ivermectin may be necessary for successful treatment.
  • Limit visitors for patients with crusted scabies; visitors should use the same contact precautions and protective clothing as staff.
  • Identify and treat all patients, staff, and visitors who may have been exposed to a patient with crusted scabies or to clothing, bedding, furniture or other items (fomites) used by such a patient; strongly consider treatment even in equivocal circumstances because controlling an outbreak involving crusted scabies can be very difficult and risk associated with treatment is relatively low.
  • Offer treatment to household members (e.g. spouses, children, etc.) of staff who are undergoing scabies treatment.
  • Treat patients, staff, and household members at the same time to prevent reexposure and continued transmission.
  • Staff generally can return to work the day after receiving a dose of treatment with permethrin or ivermectin; however, symptomatic staff who provide hands-on care to any patient may need to use disposable gloves for several days after treatment until sure they are no longer infested.
  • Use procedures that minimize risk of transmission of secondary bacterial infections that may develop with scabies.

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Environmental Disinfection

Establish appropriate procedures for environmental disinfection.

  • Ensure bedding and clothing used by a person with crusted scabies is collected and transported in a plastic bag and emptied directly into washer to avoid contaminating other surfaces and items; machine wash and dry all items using the hot water and high heat cycles (temperatures in excess of 50°C or 122°F for 10 minutes will kill mites and eggs); ensure laundry personnel use protective garments and gloves when handling contaminated items.
  • Attempt to ensure that all persons who receive treatment have the clothing and bedding they used anytime during the 3 days before treatment machine-washed and dried using the hot water and high heat cycles.
  • Clean the room of patients with crusted scabies regularly to remove contaminating skin crusts and scales that can contain many mites.
  • Thoroughly clean and vacuum the room when a patient with crusted scabies leaves the facility or moves to a new room.

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  • Establish procedures for identifying and notifying at-risk patients and staff who are no longer at the institution.
  • Ensure a proactive employee health service approach to scabies including providing information about scabies to all staff and providing dermatologic consultation for employees and, where appropriate, their household members.
  • Maintain an open and cooperative attitude between management and staff.

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For Health Professionals and Institutional Staff
Page last reviewed: November 2, 2010