where do the mites come from that cause scabies
Scabies Scabies is caused by infection with the female mite Sarcoptes scabiei var. hominis.[2] The mites burrow into the skin to live and deposit eggs.[2] The symptoms of scabies are due to an allergic reaction to the mites.[1] Often, only between 10 and 15 mites are involved in an infection.[1] Scabies is most often spread during a relatively long period of direct skin contact with an infected person (at least 10 minutes) such as that which may occur during sex.[2][9] Spread of disease may occur even if the person has not developed symptoms yet.[10] Crowded living conditions, such as those found in child-care facilities, group homes, and prisons, increase the risk of spread.[2] Areas with a lack of access to water also have higher rates of disease.[3] Crusted scabies is a more severe form of the disease.[2] It typically only occurs in those with a poor immune system and people may have millions of mites, making them much more contagious.[2] In these cases, spread of infection may occur during brief contact or by contaminated objects.[2] The mite is very small and usually not directly visible.[2] Diagnosis is based on the signs and symptoms.[4]