Intestinal and Urinary Pseudomyiasis by Psychodinae Larvae in an Adolescent: A Fact, Fallacy, or Harmless Spectator?

Myiasis is caused by fly larvae and can be classified into obligatory, facultative, and accidental (or pseudomyiasis) forms. Clogmia albipunctata, a species of Psychodinae fly, commonly found in areas such as kitchens, toilets, and drains, has been linked to urogenital and intestinal myiasis. However, recent evidence questions its role as a true causative agent of myiasis. We report a 17-year-old female who experienced intermittent larval elimination in her stool and urine, accompanied by gastrointestinal symptoms. Psychodinae larvae, likely Clogmia spp., were identified in both stool and urine samples collected from her home. No other relevant findings were found during the investigation. After explaining the fly's life cycle to the adolescent and her parents, they recognized the presence of a similar fly near the toilet. This led to a renovation of the sanitation facilities and isolation of the drainage system, after which larval elimination ceased with no recurrence. The breathing requirements of Psychodinae larvae suggest that it is unlikely they could survive, let alone develop, in the gastrointestinal or urinary tracts. Additionally, their presence has not been documented in these areas, and the suspected causative agent was not directly observed in the patient. In this case, as with similar reports, definitive conclusions are difficult to reach regarding whether these instances represent pseudomyiasis or are merely incidental findings in the environment. However, the evidence tends to favor the latter hypothesis and rules out the possibility of true myiasis. This report highlights the importance of accurately identifying the implicated species and eliminating the source of infestation to prevent recurrence.