DefinitionsDiagnosis of Scabies Confirmation of Diagnosis Treatment Environmental Control Measures Protocol For Assessment And Control Of Scabies Outbreaks in Long Term Care Facilities Institutional Treatment Plan: Selective vs Mass TreatmentReferences
Scabies is a contagious parasitic infestation of the skin caused by the mite, Sarcoptes scabiei var hominis. Although not a reportable disease, scabies outbreaks reported from long term care facilities (LTCFs) have increased in recent years. In Maryland, 61 scabies outbreaks were reported from 1986-1995, of which 57% (35/61) occurred in nursing homes. Both care givers and residents of LTCFs are at increased risk of exposure to scabies. The increased risk is attributed to several circumstances of providing and receiving care in a LTCF.
Scabies in residents of LTCF may often be atypical in appearance and symptoms, causing a delay in diagnosis as well as heavy infestation. An additional factor contributing to the increased risk of exposure is the opportunity for direct skin contact between staff and residents or residents and other residents. Such contact is increased with LTCF residents who often require assistance with dressing or positioning as well as other nursing care. Further opportunities for transmission can occur through rotation of asymptomatic staff members to various units within the LTCF.
Finally, environmental exposure to scabies can occur if residents mistakenly occupy another infested resident's bed.
Outbreak: An outbreak of scabies should be reported when a LTCF experiences two or more concurrent cases of scabies affecting residents and/or staff members. Two or more consecutive cases of scabies occurring within four to six weeks of each other should also be considered to be an outbreak.
Case: A confirmed case of scabies is defined as a person who has a skin scraping with identified mites, mite eggs, or mite feces. A probable case of scabies is a person with clinical symptoms of a persistent pruritic rash.
Contact: A contact is defined as anyone with whom a case has had skin-to-skin contact (e.g., staff member, physical therapist, phlebotomist, family member who is a regular visitor, or other residents with whom the case has had direct skin contact). Sexual partners and roommates are also contacts.
Incubation Period: The time between contact with the mite and the appearance of the symptoms of the pruritic rash varies. If the individual has never had a previous infestation, the onset of symptoms occurs two to six weeks following the initial infestation by the mite. If the individual has had a prior infestation symptoms can occur one to four days following mite infestation.
Period of Communicability: The infested individual may be asymptomatic yet able to transmit the mite to others. After infestation occurs, the mite deposits eggs under the skin of the human host. After larvae hatch from the eggs, they travel to the surface of the skin. Transmission can occur as early as two weeks after the original infestation of the individual. A person is considered to be no longer communicable 24 hours after start of effective therapy.
Diagnosis of Scabies:
Typical scabies lesions consist of papules, vesicles, or linear burrows containing the pinpoint mite; however, these may not be present on an elderly or immunocompromised infested person. Erythematous papules, excoriations, or occasionally vesicles are often located between the fingers, on the upper back, wrists, elbows, thighs, breasts, or genitalia. The lesions may also appear as eczematous plaques, pustules, or nodules located in skin folds under the breasts, around the naval, axillae, buttocks, scrotum, or at the belt line on the abdomen. Infested individuals usually complain of severe nighttime itching. The itching is often worse following a hot shower or bath. The location of scabies lesions also differs in the elderly or immunocompromised.
Residents and staff should have skin examination by inspection. New residents or those accepted in transfer from another care facility should be examined on the first day of arrival. If a resident is undergoing treatment for scabies but requires transfer to another care facility, the accepting facility must be notified of the current diagnosis of scabies in this resident prior to transfer.
Residents of LTCF are at risk for hyperinfestation with the scabies mite. Crusted scabies, known as Norwegian scabies, is extremely contagious. If even a single resident has crusted scabies, the LTCF faces a significant risk of a scabies outbreak. Lesions resemble psoriasis with heavy crusting and scaling. Fingernails and toenails often appear discolored and thickened. Individuals diagnosed with Norwegian scabies may have one of the following characteristics: a history of treatment with steroids, an impaired ability to scratch caused by neurological or psychological illness, or an otherwise impaired immune response secondary to age or illness.
Confirmation of Diagnosis:
Suspicious lesions should be scraped with a sterile needle or scalpel blade. Health care personnel can be trained to perform skin scrapings according to the following procedure:
The recommended treatment for scabies is 5% permethrin cream. Application of this cream to the skin of an infested resident should be supervised by the staff of the LTCF. Usually the cream is best applied prior to bedtime. The cream must cover all skin areas from the neck down.
In the case of an incontinent resident, the LTCF staff must ensure that any cream that is removed during bouts of incontinence is promptly replaced. Following 8-14 hours of skin contact, the cream should be removed by shower or bath. Treatment may need to be repeated in seven days if there is evidence of persistent or recurrent lesions.
An infested individual should be considered contagious until 24 hours after start of effective treatment. Itching often persists in spite of treatment and may require additional therapy for symptomatic relief.
Alternative treatments are occasionally prescribed. These may include 1% lindane cream or lotion, 6% precipitated sulfur in petroleum, or 10% crotamiton cream or lotion.
Environmental Control Measures:
While scabies is readily transmissible with skin to skin contact, the mite can only survive in the environment for 48 hours without a human host. The bedding and clothing of an infested individual may contain viable mites, but exposure to a human host must occur within a short period of time for transmission to occur.
In general, vacuuming and general cleanliness should provide adequate environmental control. Fumigation is not necessary; furniture should not be discarded. Clothing or bedding that were used by an infested individual during the seven days before effective treatment should be laundered and dried with the hot cycle or dry cleaned. Items that cannot be laundered or dry cleaned should be placed in a plastic bag and sealed for seven days to allow time for mites and eggs to die.
During an identified scabies outbreak, staff members who have been providing care to an identified case should not be rotated to other resident care units until 24 hours after completion of the staff member's scabicidal treatment. The case should also be isolated from other residents for 24 hours. Treatment of cases and contacts in a coordinated manner according to the attached protocol will minimize the inconvenience of these cohort measures.
Protocol For Assessment And Control Of Scabies Outbreaks in Long Term Care Facilities
The following protocol provides guidance for surveillance, diagnosis, and treatment of cases and contacts in LTCFs and management of outbreaks.
4. Educate staff and residents (if possible) on:
Management: Group I: Confirmed or Suspected Scabies and Contacts
Isolate case (Contact precautions) for 24 hours after start of effective therapy.
Perform environmental control measures:
Group II: Crusted Scabies or Norwegian Scabies (Hyperinfestation)
Note: These individuals have a long term rash and are very heavily infested. They are very contagious. Repeat treatments with 5% permethrin cream are usually necessary.
Institutional Treatment Plan: Selective vs Mass Treatment
Although scabies frequently presents as a widespread outbreak within a LTCF, there are circumstances in which a more selective treatment plan may be utilized. Selective Treatment Protocol If a single case of scabies (Group I, above) occurs within the population of residents or employees, a selective treatment protocol may be utilized:
Mass Treatment Protocol
A more extensive treatment plan should be utilized if any of the following occur:
The following actions should be taken:
Prompt identification and treatment of scabies cases and potential contacts remains the cornerstone of outbreak control. Education of residents, staff, and family members or regular visitors must be initiated immediately.
Finally, treatment of cases, contacts, and the environmental control measures must be coordinated. If case and contact identification is not complete or if treatment of cases and contacts does not occur at the same time, transmission of the mite will continue.
Strict surveillance for possible cases should be performed at time of resident admission or during times of skin care or bathing assistance. The unique circumstances of the LTCF provide a population that is extremely susceptible to outbreaks of scabies. Vigilant and ongoing surveillance for cases is of paramount importance within this setting.
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