Cavitary myiasis

Cavitary myiasis is a parasitic infestation caused by the larvae (maggots) of various fly species that invade natural body cavities, including the nasal passages, oral cavity, paranasal sinuses, ears, and urogenital tract. Unlike cutaneous myiasis, which affects the skin, cavitary myiasis involves deeper anatomical spaces and can lead to significant tissue destruction. The condition occurs when flies deposit their eggs or larvae in or near body openings, and the developing larvae feed on living or necrotic tissue within these cavities. Common causative species include Cochliomyia hominivorax (New World screwworm), Chrysomya bezziana (Old World screwworm), Oestrus ovis, and Wohlfahrtia magnifica, among others. Key symptoms depend on the body cavity affected but may include pain, foul-smelling discharge, bleeding, nasal obstruction, facial swelling, and in severe cases, destruction of cartilage and bone. Oral cavitary myiasis can present with swelling of the gums, palate, or lips with visible larvae. Aural (ear) myiasis may cause hearing loss, tinnitus, and secondary infection. Risk factors include poor hygiene, open wounds near body cavities, debilitated or bedridden patients, individuals with intellectual disabilities, those with oral breathing habits, and living in tropical or subtropical regions where causative fly species are endemic. Treatment involves mechanical removal of all larvae from the affected cavity, which may require endoscopic assistance depending on the location and depth of infestation. Debridement of necrotic tissue is often necessary. Topical application of substances such as chloroform, ether, or turpentine oil may be used to immobilize larvae before extraction. Systemic ivermectin has been used as an adjunctive treatment to kill remaining larvae. Antibiotics are prescribed to manage or prevent secondary bacterial infections. Surgical intervention may be required in cases with extensive tissue destruction. Prevention focuses on wound care, personal hygiene, and protection from fly exposure, particularly in vulnerable populations.

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