[Furunculoid myiasis caused by Dermatobia hominis]. / Miásis forunculoide por "dermatobia hominis"

ABSTRACT

The authors report a case of forunculoid miasis by "Dermatobia hominis" ("Ura" fly). a process that being not very common in the Argentine Republic is sometimes misjudged as a furunculosis. The patient reported, a white woman, 51, travelled to a zone where this parasitose is endemid. After some time of her stay there, she noted three small nodes in her vulvar region. They grew on until reaching nearly the size of a walnut. At her first consultation with a gynecologist it was taken as a case of furuncolosis and treated with antibiotics. As the treatment didn't prove succesful, she asked for dermatological advice. It was then possible to verify the presence of three nodes. In the central hole of one of them, there could be seen a whitish body that soon disappeared inwards. This lead to the diagnosis of forunculoid miasis. An accurate and easy-to-perform treatment was carried out a 1% solution of formaldehyde in distilled water was infused through the central hole of each node. This determined the larva's caudal extremity to appear in search of air. It was taken advantage of this situation to remove the larvae with a pair of nippers. "Dermatobia hominis" is widely spread in the warm-climated Argentine northern provinces of Chaco, Formosa and Misiones, as well as in Brazil, Paraguay and some regions of Uruguay. It is also known under the name of "Ura". It is a large fly, yellow faced, with dark-blue thorax; an almost rombic metallic-blue abdomen, orange antennae and legs, and dark-brown wings. It lives on the nutrients spared during its larval stage and both fecundation and oviposition, take place along its week-long life. The fecundated female catches different haematophagus insects on the wing, sticking sets of eggs to their abdomens. An embryo developes in each egg, being ready to emerge in a week but does this only when the bearer insect settles on a homeothermal being piercing and penetrating the skin of the new guest in about 10 minutes.