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- A contagious parasitic infection of the skin caused by the mite Sarcoptes scabiei, var. hominis
- System(s) affected: skin/exocrine
- Synonym(s): sarcoptic mange
Predominant age: children and young adults
Prevalence varies substantially worldwide but is more common in resource-poor settings (1):
- May be more prevalent in urban areas and areas of overcrowding
- Common in developing countries particularly tropical climates; 2013 added to World Health Organization list of neglected tropical diseases
Etiology and Pathophysiology
- Itching is a delayed hypersensitivity reaction to the mite saliva, eggs, or excrement.
- S. scabiei, var. hominis
- An obligate human parasite
- Female mite lays eggs in burrows in the stratum corneum and epidermis.
- Primarily transmitted by prolonged human-to-human direct skin contact
- Infrequently transmitted via fomites (e.g., bedding, clothing, or furnishings)
- Personal skin-to-skin contact (e.g., sexual promiscuity, crowding, nosocomial infection)
- Poor nutritional status, poverty, and homelessness
- Hot, tropical climates
- Seasonal variation: Incidence may be higher in the winter than in the summer (may be due to overcrowding).
- Immunocompromised patients, including those with HIV/AIDS, are at increased risk of developing severe (crusted/Norwegian) scabies.
Prevent outbreaks by prompt treatment and cleansing of fomites (see “Additional Therapies”).