Cutaneous myiasis following travel to Belize.

Abstract

Two days after returning from Belize, a 70‐vear‐old man developed three nonhealing ulcers with serosanguinous drainage on the right posterior ankle. He recalled mildly pruritic “mosquito bites” on the ankles prior to leaving Belize, but no evidence of skin breakdown. Tbe patient denied fever, chills, or other systemic symptoms associated witb his skin lesions.A one‐week course of cephalexin, 500 mg po q.i.d., given for “superficial cellulitis,” failed to improve the plaque on the right ankle. The patient was evaluated in the dermatology department 4 weeks after his return from Belize with no progression of the ankle lesions. The examination showed a 4 x7 cm indurated, nontender, erythematous plaque with three sinuses draining serosanguinous fluid (Fig. 1).A skin biopsy was performed on an area containing a draining sinus tract and submitted for routine and special stains. Tissue and wound cultures were negative for bacteria (aerobic and anaerobic), fungi, mycobacteria, and Leishmania. Histopathologic Findings: The deep retlcular dermis and subcutis showed an extensive, polymorphous, inflammatory reaction surrounding a parasitic structure that measured 1.8 mm in diameter (Fig. 2). The parasite had a thick eosinophilic cuticle with striated muscle visible around the out‐lines of the alimentary tube and other organs (Fig. 3). The morphologic appearance of the parasite was consistent with the larva of a fly, most likely of the Dermatobia species. Clinical Course: Conservative treatment with polymyxin B sulfate‐bacitracin zinc ointment and ace wrap occlusion for 2 days resulted in the extraction of two mature larvae (Fig. 4). The patient reported the sensation of “movement” within the sinuses immediately prior to larval extraction. The third larval specimen was contained in the skin biopsy tissue. All three sites of larval penetration showed rapid healing following the extraction of the larvae.