In addition to the mite that causes sarcoptic scabies, there are several other species that occasionally infest human skin and cause a temporary dermatitis, although they are incapable of establishing themselves on this aberrant host. These mites belong to the families Cheyletidae, Dermanyssidae, and Macronyssidae. Animals play an essential role in the life cycle of the flies whose larvae cause specific myiases. Man is only an accidental host of these larvae, and in some myiases, such as those due to Oestrus ovis or Gasterophilus sp., an aberrant host in which the larvae cannot complete their development. Larval invasions of human skin or natural cavities occur when there is a high incidence of animal myiasis. Pentasomes (Armillifer sp.) are wormlike arthropods that are almost exclusively parasites of the reptilian respiratory system. Snakes are the definitive hosts and many wild rodents, on which snakes feed are the intermediate hosts. The female parasite deposits eggs in the respiratory cavities of the reptiles. The eggs are expectorated or swallowed and then eliminated with the feces. Humans can be accidental hosts, by handling infected reptiles and placing contaminated hands to the mouth. In humans the infection is usually asymptomatic. The encapsulated larvae might be found during laparotomies or can be diagnosed by radiographic examination.

PREVENTION/CONTROL:

Fleas, ticks, and mites should be controlled. Gloves and protective clothing should be worn when handling lab animals.