Cutaneous Myiasis in an Immunocompromised Patient: Climate Change as an Emerging Driver

Background Cutaneous myiasis, an infestation by dipterous fly larvae, is uncommon in North America due to improved sanitation and wound care. However, climate-related ecological changes may expand the geographic range and seasonal activity of causative flies, creating new challenges for dermatologists. Case Presentation A 50-year-old man with advanced HIV/AIDS (CD4 <35 cells/µL) and recurrent anal squamous cell carcinoma presented to Pennsylvania Hospital with foul odor, abdominal discomfort, and visible movement within a chronic perineal wound. Examination revealed multiple live larvae within necrotic perineal tissue and around the stoma site. Limited access to wound care contributed to delayed presentation and poor wound management. Approximately 20–30 larvae were mechanically removed, followed by irrigation and wound care. No secondary bacterial infection was identified. Discussion This case underscores an emerging intersection between climate change, severe immunosuppression, oncology, and healthcare inequity. Wound myiasis is rarely reported in temperate regions of the United States, making this Pennsylvania presentation particularly notable in a patient without travel exposure. As warming temperatures and prolonged warm seasons alter fly distribution and breeding patterns, dermatologists may increasingly encounter parasitic infestations previously considered geographically improbable. This case also highlights how delayed access to wound care and profound immunocompromise can create ideal conditions for infestation and rapid tissue deterioration. Early recognition is critical to prevent extensive tissue destruction, secondary infection, and missed opportunities for intervention in vulnerable populations. Conclusion Clinicians should maintain suspicion for myiasis in vulnerable patients, even without travel history, as climate change may alter the epidemiology of parasitic skin disease.