Scabies

FAQs for Health Care Providers

Scabies: Risk, Diagnosis, and Treatment in Afghan Evacuees

Scabies is a cutaneous ectoparasitic disease caused by the microscopic human mite Sarcoptes scabiei var hominis. The mites burrow into the upper layer of the skin where they live and lay eggs, which induces a hypersensitivity reaction leading to inflammation and intense itching. Scratching can lead to secondary bacterial infection. Scabies is contagious and can spread to multiple household members.

Have there been confirmed cases in the Afghan evacuees? Yes

Epidemology

  • An estimated 200 million people worldwide suffer from scabies at any given time

  • Overall prevalence reported in the literature ranges from 0.2-71%, with children in resource-poor areas commonly having between 5-10% prevalence

  • No specific up to date epidemiology of scabies in Afghanistan or in evacuees

When should I consider scabies?

Scabies causes intense, generalized itching and characteristic skin lesions. The lesions often appear as a papules, vesicles, pustules, and burrows, the latter which represents the mite burrowing in the skin. The lesions are often excoriated. Scabies often affects the axillary folds, breasts, abdominal skin, hands, interdigital web spaces, belt line, genital area, and ankles. In infants, lesions can appear as pustules on the palms and soles, termed “infantile scabies.” Children can have heavy involvement of their whole body, including the face and neck. After puberty, genital nodules are common. Lesions can become superinfected with Staphylococcus or Streptococcus bacteria, and present as impetigo (thick, crusted lesions).

Scabies in the axillary folds (image source: CDC)
Scabies on the abdomen (image source: CDC)
Scabies on the hand (image source: CDC)
Scabies in the interdigital web spaces (image source: CDC)
Scabies on the genitals (image source: CDC)

Crusted scabies is characterized by thick crusts of skin that contain large numbers of scabies mites and eggs. The large numbers of mites make an individual highly contagious to other persons. Crusted scabies is most commonly seen in persons who are elderly, immunocompromised, or unable to care for themselves.

Is scabies contagious? Yes

Scabies is transmitted through prolonged direct skin to skin contact, usually 10-20 minutes. Crusted scabies is much more infectious. Scabies can also be transmitted indirectly by mites present in contaminated items such as clothing, bedding, and furniture. Persons with crusted scabies should be isolated and receive timely medical treatment for their infestation to prevent outbreaks of scabies.

Are there special infectious disease precautions for someone with scabies?

  • For healthcare workers, standard contact precautions and good hand washing are recommended to reduce the risk of transmission.

  • For families, we recommend laundering all clothing, towels, and bedding in hot water prior to (or at) move in to new quarters. Items that cannot laundered can be bagged in plastic for 3 days.

  • No quarantine or public health reporting is needed although if planning to move into a new household or congregate living, expert consultation should be obtained (if during medical intake/screening examination, please contact infectious diseases on call).

How do I diagnose scabies?

  • Scabies is diagnosed clinically based on the characteristic rash and itching (see photos above) (See the following: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7687112/).

  • It is ideal to diagnose through a skin scraping examined under a microscope for evidence of mite, eggs, or fecal matter. A patient can still have a scabies infestation even if the mites, eggs, or fecal matter are not seen.

  • Scabies impetiginized with S. aureus or S. pyogenes may have yellow crusting, redness, ulceration, and pustules.

What is the treatment for scabies?

  • Several treatments are available for scabies.

  • Treat with permethrin 5% cream from neck down (including into skin folds); leave on 8 hours, wash off and repeat in one week. Permethrin may be used in those > 2 months of age. All close contacts should treated at same time.

  • Ivermectin is a common treatment (although not FDA approved for scabies) and is an alternative and may have the added benefit of treating certain parasitic infections such as Strongyloides or hookworm. Ivermectin should not be used without consultation in children weighing < 15 kgs.

  • More information on treatment can be found here.

  • Impetiginized scabies should also be treated with oral antibiotics to cover Staphylococcus and Streptococcus

  • Trim fingernails

  • Laundering clothing, towels, and bedding as above, once treatment has been started

  • Treatment for crusted scabies should be determined on a case-by-case basis and may include oral (e.g. ivermectin) and topical (e.g. permethrin) treatment to kill mites and keratolytics to remove crust

Additional Resources and References

Contributors

Kristen Bastug, MD

Alexia Knapp, MD

William Stauffer, MD

Scabies.pdf