Loxosceles venom is cytotoxic and primarily consists of which two constituents?

The venom of Loxosceles spiders, commonly known as recluse spiders, is particularly noted for its cytotoxic components, which can cause significant tissue damage. The primary constituents of this venom that are responsible for its cytotoxic effects are sphingomyelinase D and hyaluronidase.

Sphingomyelinase D is a key enzyme that breaks down sphingomyelin, a component of cell membranes, leading to the disruption of cellular integrity and promoting cell death. This action is a major contributor to the necrotic lesions often associated with recluse spider bites.

Hyaluronidase, on the other hand, acts by breaking down hyaluronic acid, which is an important part of the extracellular matrix in tissues. This breakdown facilitates the spread of venom through the interstitial spaces, allowing for greater tissue damage and more extensive impacts beyond the initial bite site.

Together, these two components of the venom create a powerful cytotoxic effect that is characteristic of bites from Loxosceles spiders, leading to clinical manifestations such as ulceration and necrosis in affected individuals. This understanding of the venom composition is crucial for proper assessment and treatment of spider bites in medical settings.