How Do I Get Tested For Scabies?

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Scabies Mite - Sarcoptes scabiei var. hominis. CDC/Joe Miller/Reed & Carnrick Pharmaceuticals

Scabies is normally diagnosed by the appearance of the skin rash it causes as well as the intense itching associated with the condition, which is even more intense at night. The scabies rash usually consists of small red bumps that look like pimples. The rash can also cause blisters and scaling of the skin, and sores are highly susceptible to infection if scratched.

Although it is possible to get scabies anywhere on the body, some of the most common locations for the scabies rash are the:

  • webbing between the fingers
  • wrists and elbows
  • nipples
  • penis
  • buttocks
  • waist/belt-line

Unfortunately, scabies rashes are easily mistaken for other types of skin infections. The main feature that differentiates the rash from those caused by infectious conditions such as chicken pox, measles, and even smallpox -- or other concerns such as folliculitis and eczema --  is that the itching is substantially worse at night, because of the nocturnal behavior of the scabies mite.

It is because of how easy it is to mistake scabies rashes for other skin conditions that, if a doctor is concerned you might have scabies, they will often scrape the rash and send it for analysis. This scraping of the rash is used to test for the presence of the scabies mites, their eggs, or their feces. However, this test has a high occurrence of false negatives. In other words, you may still have scabies even if the skin scraping comes back negative.

Remember, scabies is not always a sexually transmitted disease. It is incredibly contagious, and it is actually more commonly thought of as a disease of children.

Sources

Brodell RT, Helms SE. Office dermatologic testing: the scabies preparation. Am Fam Physician. 1991 Aug;44(2):505-8.

de Vries HJ. Skin as an indicator for sexually transmitted infections. Clin Dermatol. 2014 Mar-Apr;32(2):196-208. doi: 10.1016/j.clindermatol.2013.08.003.

Jacks SK, Lewis EA, Witman PM. The curette prep: a modification of the traditional scabies preparation. Pediatr Dermatol. 2012 Jul-Aug;29(4):544-5. doi: 10.1111/j.1525-1470.2012.01745.x.

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