Scabies are caused from a mite called Sarcoptes scabiei. It is a contagious skin condition which is transmitted mainly through skin to skin contact. They can also be transferred from infected clothing or bedding. They can only survive three days without a human host. The mites  secrete enzymes to dissolve the epidermal layer  in order to penetrate the skin. The mites feed on the skin and burrow further to lay eggs.

 

Scabie mite life cycle

 

Immune response to scabies

The scabie mite has genes which prevent the immune system from responding to the presence of mites within the skin generally until days or weeks after the infection. When the scabie mite burrows, lays eggs and excretes faeces an allergic reaction will occur. Once infected the life cycle of the mites will continue unless medical treatment is sought.

 

Signs and symptoms

  • Rash
  • Itching
  • Dermatitis
  • Fever

 

Diagnostics

There are two common ways to diagnose the presence of scabies, a skin scrapping and using a felt tip marker.

Retrieved from https://www.youtube.com/watch?v=BLry2yJsUuI

Treatment

  • topical medication 5% permethrine cream
  • anti-parasitic medication
  • itching can be treated with antihistamines
  • Vacuuming home
  • Cleaning linen and clothes
  • Bagging non washable items for 5 days
  • Finger nails cut and cleaned thoroughly and regularly

Secondary infection may occur from scratching the skin leading to a bacterial infection.

 

Resources

DermNet NZ: http://www.dermnetnz.org/arthropods/pdf/scabies-dermnetnz.pdf

CDC Scabies Info: http://www.dpd.cdc.gov/dpdx/HTML/Scabies.htm

Epidemiology of Scabies: http://epirev.oxfordjournals.org/cgi/reprint/11/1/126

 

References

Winters, L. (2009). Scabies. Retrieved March 2, 2017, from https://web.stanford.edu/group/parasites/ParaSites2009/LeighaWinters_Scabies/LeighaWinters_Scabies.htm

 

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