Coombs-Positive Hemolytic Anemia Secondary to Brown Recluse Spider Bite: A Review of the Literature and Discussion of Treatment
The bite of the brown recluse spider (Loxosceles reclusa) typically results in local, dermonecrotic skin lesions. Rarely, these bites may precipitate systemic disturbances of varying severity collectively known as systemic loxoscelism. The more severe systemic alterations attributed to the venom of this arachnid include hemolytic anemia, multiorgan failure, disseminated intravascular coagulation, or even death. Coombs-positive hemolysis associated with brown recluse spider bites has rarely been documented in the literature. We report 2 cases of systemic loxoscelism in young women associated with severe Coombs-positive hemolytic anemia and systemic symptoms requiring hospitalization. Both patients were treated with aggressive wound care, hematologic monitoring with blood transfusion, and intravenous fluid replacement. Recovery was excellent in both cases. We review the literature and discuss the controversies surrounding the treatment of more severe brown recluse bite reactions.
Other treatments also have been reported, including colchicine, hyperbaric oxygen, cyproheptadine, electrical shock treatment, and brown recluse specific antivenin.7,21,35 Despite early promise, all of these treatments have been met with mixed results in subsequent studies. In one study, the early use of intradermal injection of polyclonal antiloxosceles Fab fragments was shown to attenuate necrosis in an animal model up to 4 hours after envenomation.36 Unfortunately, it is difficult to predict which patients would benefit from the antivenin. Additionally, the antivenin has to be administered in the first 24 hours after a bite, before most patients are seen by a physician.
In our cases, both patients were young and presented with a recent history of a bite by a brown spider consistent with a brown recluse. They were both systemically ill with a profound hemolytic anemia. They were both treated with aggressive wound management, hematologic monitoring with blood transfusion, and expectant care. Patient 1 was given intravenous corticosteroids, and patient 2 was treated with aggressive wound management only. It is not known whether the corticosteroids given in our first patient affected her clinical course because both patients experienced a complete recovery. Like other case reports of treatment in brown recluse spider bites, it is difficult to tell what effect, if any, the treatment has on clinical outcome because most patients, even those with serious systemic symptoms, make a complete recovery. This routine excellent outcome with supportive care only suggests that the use of systemic treatment or surgery is unnecessary and exposes the patient to risks of treatments with unproven efficacies.
Conclusion
Brown recluse spider bites usually cause a local dermonecrotic reaction but can cause a serious systemic illness and rarely death. We report the fifth and sixth cases of Coombs-positive hemolytic anemia associated with presumed L reclusa envenomation. The first 4 reported cases of Coombs-positive hemolysis were positive for IgG and/or complement. This was confirmed in our cases. The treatment of loxoscelism is controversial in the literature and in practice. We must keep in mind to "first, do no harm" when choosing treatments for patients with brown recluse bites. Many of the treatments previously described, including dapsone, have only anecdotal support for their use. Others, such as early surgery, have been shown to actually delay healing and worsen outcomes. Patients with brown recluse bites typically do well with conservative management alone and agents such as dapsone and systemic corticosteroids can have serious adverse reactions. It is our view that patients with local dermonecrotic skin lesions should be treated with aggressive wound care only. For patients who develop systemic loxoscelism, hemodynamic support and blood transfusion should remain the mainstay of therapy. Further study is needed to determine the benefits of systemic corticosteroid use in patients with Coombs-positive hemolytic anemia secondary to systemic loxoscelism.
