Loxoscelism represents clinical manifestations induced by spiders bite (Loxosceles Genus). Cutaneous loxoscelism involve dermonecrosis with gravitational spreading while systemic loxoscelism may include renal failure and haematological disturbances. The venom contains several toxins, the most biochemically and biologically studied is the dermonecrotic toxin, a sphyngomyelinase, which reproduces mostly toxic effects as well as described for the crude venom. Herein, we describe cloning, heterologous expression and purification of two novel isoforms of the dermonecrotic toxin: LiRecDT4 and LiRecDT5. The recombinant proteins stably expressed in Escherichia coli cells were purified from culture supernatants in a single step using Ni^2-chelating chromatography producing soluble proteins of 34kDa (LiRecDT4) and 37kDa (LiRecDT5). Both recombinant proteins were recognized by hiperimmune serum against whole venom and by a specific antibody to dermonecrotic toxin. Also, recombinant isoforms with lipase activity induced experimental skin lesions and caused a massive inflammatory response in rabbit skin dermis. The toxins displayed differential activities of platelet aggregation, increase in vascular permeability as well as not caused death in mice. These characteristics in combination with functional studies illustrates that a family of dermonecrotic toxins exists, and includes two novel members that are useful for future structural and functional studies. They will also be useful as biotechnological tools, for example, for inflammatory and platelet aggregating studies and antigens for serum therapy source.