As an increasing number of travelers visit tropical regions, western physicians will find themselves treating more patients with travel-associated infection.1 Among them, skin diseases account for nearly 10% of medical situations, and myiasis represents 7% to 11% of imported dermatosis.1
A man in his 60s presented with pruriginous perineal nodules on his return from travel in South America. There was no history of insect or mosquito bites, and the patient denied total nudity or defecation in the outdoor environment. Within 2 days of his return, he presented with painful, erythematous, scrotal furuncle-like nodules, and he described a sensation of movement within the nodules. Ten furunculoid lesions with a central punctum exuding serosanguineous fluid were identified on the scrotum, the gluteal furrow, the inguinal fold, and the perianal region (Figure, A). No cellulitis or lymphadenopathy were highlighted, and the patient remained afebrile. Biological examination showed a normal blood cell count without hypereosinophilia, and moderate inflammation. Furuncular myiasis was diagnosed after occlusion of the lesions by petroleum jelly, encouraging movement of the maggots. Each nodule excision extracted 1 larva (Figure, B). Parasitologic examination identified Dermatobia hominis larvae, even though they usually affect exposed areas. Follow-up at 3 weeks demonstrated complete recovery.
A, Ten perineal furunculoid lesions. B, One larva of D hominis was surgically extracted from each lesion.
To our knowledge, we report the first multifocal perineal infestation by D hominis. This atypical presentation with focalized infestation in the inguinal region raises questions about the mode of contamination. The most common agents responsible for furuncular myiasis are D hominis in the Caribbean and Central and South America and Cordylobia anthropophaga in sub-Saharan Africa.2 Number and localization of the lesions vary according to the causative species. In South America, where D hominis is the most represented agent, skin lesions usually develop on exposed areas because of a transmission phenomenon called phoresia involving mosquito bites.2,3 African myiasis caused by C anthropophaga can be seen on covered areas because of maggots deposited on drying clothing. Nevertheless, atypical localizations of D hominis myiasis are described such as ophthalmic (conjunctival or palpebral), penile, or scrotal but remain rare and most of the time unifocal.2,4 Indeed, D hominis usually targets uncovered areas of the body or can exceptionally affect covered areas with just 1 or 2 lesions.
Treatment of D hominis myiasis requires total extraction (mechanical or surgical) of the subcutaneous larvae.5 A common preliminary stage consists of occluding the central ostium of each lesion with a thick substance, such as petroleum jelly, to induce maggot hypoxia and spontaneous emergence to aid in extraction. The systematic removal of the entire larva was necessary to prevent constitution of an inflammatory granuloma, and associated antibiotic treatment was used to prevent secondary bacterial infection.
Corresponding Author: Jean-Christophe Lagier, MD, PhD, Aix Marseille Université, URMITE, UM63, CNRS 7278, IRD 198, INSERM 1095, 27 Bd Jean Moulin, 13005 Marseille, France (email@example.com).
Published Online: September 16, 2015. doi:10.1001/jamadermatol.2015.2608.
Conflict of Interest Disclosures: None reported.
Additional Contributions: Karolina Griffiths, MD, Pôle Infectieux, Institut Hospitalo-Universitaire Méditerranée Infection, Assistance Publique Hôpitaux de Marseille, Centre Hospitalier Universitaire Nord, Marseille, France, provided English reviewing. She was not compensated for her contribution.
Gaci R, Delord M, Parola P, Brouqui P, Lagier J. Extended Perineal Dermatobia hominis Myiasis in a Traveler Returning From South America. JAMA Dermatol. 2015;151(12):1389-1390. doi:10.1001/jamadermatol.2015.2608