Epidemiology of common parasitic infections of the skin in infants and children (original) (raw)

2002, Clinics in Dermatology

embers of three taxonomic groups-protozoa, helminths, and arthropods-cause parasitic infections of the skin. Protozoans cause trypanosomiasis and leishmaniasis, whereas cutaneous larva migrans and cercarial dermatitis are attributed to infections with certain helminths. On the other hand, cutaneous myiasis, tungiasis, scabies, and allergic and toxic reactions are caused by arthropods. These conditions, their significance, and their recent epidemiological developments, are reviewed in this article. The term "parasite" is derived from the Greek parasitos, to denote an uninvited person who has no place at the table but sits aside and receives leftovers. It refers usually to an animal or animallike protistan that lives on (ectoparasite) or in (endoparasite) another animal. In this animal-to-animal association, the parasite is benefited while the other animal, normally referred to as the host, is harmed, and the association is termed parasitism. The host unwillingly provides the parasite with a relatively stable biotic environment where nutrients, shelter, or both are provided. The host, however, does not sit idle but fights back, mainly through tissue reactions, digestive enzymes, and cellular or humoral responses. It is postulated that the longer the evolutionary relationship between the parasite and the host, the more adapted they are to each other. 1 The degree of association between the parasites affecting the skin and their hosts varies. Some spend their whole life cycle in the skin as is the case with Sarcoptes scabiei, but others come in contact with the host for a very short period of time as is the case with a female mosquito that comes to take a blood meal within a minute. In between these two examples, there are many parasites that vary in the duration of their association with the hosts. The parasites that affect the skin of infants and children are many and belong to either of the following three groups: