Head and Neck Myiasis, Cutaneous Malignancy, and Infection: A Case Series and Review of the Literature

Abstract

Background

There is a paucity of literature on wound myiasis of the head and neck originating in the United States. To our knowledge, only three reports during the past 20 years exist in the literature. Even less common is a case of recurrent myiasis, with only one report published from India during the 1970s. There is often a preconceived notion that larvae are noninvasive and “only eat dead tissue.” This mentality must be corrected; invasive larvae exist, there are unique myiasis-related infections, and serious complications can occur. We review the literature and describe recent cases of head and neck myiasis treated at our institution in upstate New York.

Case Reports

Four cases, all initially presenting to the emergency department, were identified. Each case was superimposed on cutaneous malignancy and all patients presented with leukocytosis and positive blood or wound cultures. In the case of the recurrent myiasis, initial treatment was external beam radiation therapy for the malignancy, which had the added benefit of eradicating the larvae. Treatment for the other cases was limited to antibiotics and supportive care for medical comorbidities.

Why Should an Emergency Physician Be Aware of This?

Serious complications can develop from head and neck myiasis and, in our experience, an underlying malignancy should be suspected. Proper management is critical and should include, at a minimum, empiric antibiotics, tetanus prophylaxis, biopsy of the surrounding tissue, and reporting to the appropriate health agency. Additional management can include bedside debridement, pharmacologic antiparasitics, and treatment of the underlying disorder.

Introduction

Myiasis is an ectoparasitic infestation of tissue by the dipterous larvae of higher flies; its name is derived from the Greek word for fly, “myia” (1). In Hindu mythology, it is considered “God's punishment of sinners” (2). Overall, this condition is rare in humans and is usually seen in conjunction with tropical and subtropical location, poor hygiene, suboptimal housing conditions, and overall debilitated state (1, 3, 4, 5. Myiasis can be caused by obligate, facultative, or accidental larval parasites. Obligate parasites must live and feed on hosts. Facultative parasites preferentially feed on decaying matter and tend not to invade healthy tissue. Accidental parasites are eggs or larvae that are inhaled or swallowed inadvertently. Clinical categories of infestation include furuncular, wound, intestinal, and cavitary. In the head and neck, obligate and facultative parasites are the most common and usually result in wound infestation. Of note, there are species of larvae used for therapeutic purposes, specifically the lucilia species. However, they are also documented to cause pathologic myiasis in humans, with some strains being locally invasive 6, 7.

Myiasis has been reported in a variety of body subsites, including the head and neck, the oral cavity, genitals, and the brain. Often, this is after a traumatic or surgical wound or site of pre-existing lesion 1, 2, 8, 9, 10, 11, 12. Factors that predispose to myiasis include increased age (older than 60 years); low socioeconomic status; and medical comorbidities, such as vascular or respiratory compromise 1, 5, 13, 14. However, there is a paucity of literature on myiasis originating in the United States. We review the literature and describe four recent cases of head and neck myiasis treated at our institution.