Journal de toxicologie clinique
Libre accès

Abstrait

Rattlesnake Envenomation in the Setting of Disrupted Lymphatic Flow: A Case Series

Molly Brady, Mary Junak, Geoffrey Smelski, Farshad Mazda Shirazi

Objective: Rattlesnake envenomation is a pathophysiologically complex process with a range of local effects including pain, erythema, local edema resembling compartment syndrome, ecchymosis that extends beyond the bitten extremity, as well as the development of blisters, bullae and tissue necrosis in severe cases. Previous animal studies have suggested that lymphatic flow is a crucial part of dissemination of venom after initial injection to produce systemic effects. However, the effects of baseline lymphatic obstruction on local injury in humans have yet to be described clinically.

Methods: Three cases of patients that sustained rattlesnake bites with a history of lymphatic disruptions were reviewed, two with histories of mastectomies and one with chronic lower extremity lymphedema. All three patients experienced bites on the limb affected by lymphatic obstruction, yet their presentation of local symptoms and treatment regimens varied.

Results: The first case describes a woman with a history of bilateral mastectomy and complete lymph node dissection who was bitten on her upper extremity and developed severe local cytotoxicity and tissue necrosis despite standard antivenom administration protocols. Providers in the second case treated the patient, who also had a history of mastectomy and complete lymph node dissection, more aggressively with repeat loading doses rather than maintenance dosing based on standard criteria of swelling progression greater than an inch an hour. In this instance, the patient had a favorable outcome with complete recovery of the local tissue and no evidence of necrosis. The final case, which involved a bite on an extremity with chronic lymphedema, resulted in delayed necrotic skin breakdown requiring two surgical debridements after initial standard antivenom dosing.

Conclusion: The clinical outcomes of these cases revealed a more severe local injury with lymphatic disruption, suggesting that either venom is unable to travel systemically and concentrates at the site of injection or that antivenom therapy is unable to reach the site of the bite. Future studies are needed to better understand this relationship as this case series suggests that lymphatic obstruction may be a risk factor for more severe local injury.