Myase sous-cutanée. À propos d'un cas

Abstract

Although myiasis or hypodermiasis is a parasitic disease that theoretically has practically been eradicated, a new case has recently been reported in Lower Normandy, in a bovine husbandry region. A seven-year-old-girl was hospitalized in November 1998 for an edema of variable size on the right eyelid, which was not painful and non-inflammatory, with accompanying ptosis. A number of subcutaneous nodules were found on the forehead above the right eye socket. The right eye itself was unaffected. The symptoms had evolved over a ten-day period. Further examination did not detect any sign of eosinophilia, and the hypodermiasis and toxocariasis serologies were negative. The clinical evolution was characterized by the regression and reappearance of the edema on several occasions, after which the edematous mass became progressively larger, more swollen and painful, so that it was no longer possible to open the eye. The subcutaneous nodules partially disappeared when the edema increased in size. Six weeks after the onset of clinical signs, eosinophilia was observed and the hypodermiasis serology was positive. Due to the limitation of the visual field as a result of the edema, a short-term steroid treatment (seven days) was orally administered. The patient recovered, and no further edematous signs were noted. However, contrary to what had been reported in the literature, the larvae did not appear on the surface of the skin. In conclusion, in bovine husbandry regions the diagnosis of hypodermiasis should always be kept in mind in the event of clinical signs indicative of larval migration, even in the initial absence of eosinophilia, and even with an initially negative hypodermiasis serology. This disease should soon be eradicated, as regional bovine treatment programs have been set up to systematically treat the cattle and eliminate the larvae.