ABSTRACT
Background: Atraumatic upper extremity arterial thrombosis is uncommon. We present a case of radial and ulnar artery thrombosis with critical limb ischemia, with symptoms resolving after remediation of a black mold home infestation. This case highlights the importance of identifying potential environmental exposures in uncommon clinical presentations. Case presentation: Chart review of all visits in two hospital systems. Informed consent was obtained from the patient. Result(s): A 51-year-old male noted pain and paresthesia of the left hand. Critical ischemia was found with mid-forearm occlusion of the radial and ulnar arteries;surgical care included no distal target for bypass and digital ray amputation. Workup did not reveal autoimmunity, thrombophilia, or source of embolism. Symptoms were recurrent with ongoing ischemia and tissue loss. Further evaluation identified a home water leak. Professional remediation of black mold coincided with resolution of pain, discoloration, and ulceration without return of symptoms at follow up of 22 months. Conclusion(s): Immune-mediated mechanisms can lead to clinical thrombotic events. Vascular occlusion related to COVID-19 has stimulated interest in thrombotic pathways not routinely emphasized. We postulate neutrophil extracellular traps (NETs), triggered by chronic exposure to mold, contributed to persistent digital ischemia. NETs are fibrous extensions of extracellular strings of DNA, antimicrobial peptides, and chromatin that bind pathogenic microbes and provide scaffolding for thrombi, triggering vascular occlusion. This is a novel case of upper extremity arterial occlusion leading to amputation associated with exposure to black mold. Thrombosis may be related to NETs formation and symptoms did not resolve until the environmental mediator was eradicated. Environmental exposure should be considered in otherwise healthy patients who present with atraumatic critical digital ischemia without thrombophilia, autoimmunity, illicit drug use, or vasculitis.