A 52–year–old female with end–stage liver disease and no recent travel history sustained head trauma 3 weeks prior to presentation that required laceration repair. She was transferred to our medicine service from an outside hospital Emergency Department after being found down with evident maggot infestation. Exam was significant for presence of larvae in her right ear canal and in her scalp wounds as well as grade I hepatic encephalopathy, ascites, and lower extremity edema. Her CBC displayed mild leukocytosis (11.2) and tissue culture grew MRSA and polymicrobial flora. Computed Tomography of the head demonstrated scalp wounds penetrating to bone, intact and thickened tympanic membranes, and no evidence of brain involvement. ENT and Plastic Surgery performed multiple procedures involving maggot removal and debridement of scalp wounds. The patient completed a 2–week course of antibiotics and was discharged.
Semi–specific myiasis results from deposition of fly eggs in decaying animal matter or in a living host if open wounds are present. Myiasis infestation occurs commonly in tropical areas but is rare in the US and rarer in arid climates, such as Colorado. Myiasis can no longer be considered a disease restricted to the tropics. Immigration, global commerce, eco–tourism, and global warming have contributed to an increased number of US cases involving these non–native species. Larvae found in wounds should not be considered therapeutic. Therapeutic larvae spare vital tissue whereas acquired larvae invade necrotic and healthy tissue. Treatment for myiasis involves larvae removal, devitalized tissue debridement, and occasionally larvacides. Early treatment is curative and crucial to prevent invasion of healthy tissue.
We present an unusual case of acquired cutaneous and cavitary myiasis following head trauma. Patients with poor personal hygiene and environmental exposure are at risk for developing myiasis, even in developed countries and arid climates.