RESUMO
A previously healthy 35-year-old female was bitten on the anterior right thigh by a brown spider while dressing her trousers; the spider was stored and later identified as an adult female Loxosceles anomala. Clinical evolution involved a relatively painless bite with mild itching, followed by local, indurated swelling and a transient, generalized erythrodermic rash at 24 h post-bite. The local discomfort was progressive, and involved changes in the lesion pattern, with pain of increasing intensity. The patient was admitted 60 h post-bite, showing an irregular blue plaque surrounded by an erythematous halo lesion, located over an area of indurated swelling. Considering the presumptive diagnosis of cutaneous loxoscelism, she was treated with five vials of anti-arachnidic antivenom i.v. without adverse effects. There was progressive improvement, with no dermonecrosis or hemolysis; complete lesion healing was observed by Day 55. The clinical features and outcome were compatible with cutaneous loxoscelism and similar to those reported for other Loxosceles species.
Assuntos
Eritema/etiologia , Diester Fosfórico Hidrolases/intoxicação , Picada de Aranha/etiologia , Venenos de Aranha/intoxicação , Adulto , Animais , Antivenenos/uso terapêutico , Eritema/terapia , Feminino , Humanos , Picada de Aranha/terapiaRESUMO
Loxoscelism, is caused by the bite of Loxosceles laeta spiders. It has two clinical forms: cutaneous loxoscelism (CL) and viscerocutaneous loxoscelism (VCL). VCL is characterized by hematuria, hemoglobinuria, jaundice, fever and sensorial involvement. In severe cases there is massive hemolysis and renal failure, with high lethality. We report a 71 year-old man, brought to the hospital five days after suffering a spider bite. The patient was admitted with a severe kidney failure, hemolysis, metabolic acidosis and clotting disorder. The patient was managed with adrenal steroids and dialisys but died five weeks after hospital admission. This particular patient consulted late and had multiple factors of poor prognosis.
Assuntos
Injúria Renal Aguda/etiologia , Diester Fosfórico Hidrolases/intoxicação , Picada de Aranha/complicações , Venenos de Aranha/intoxicação , Aranhas , Idoso , Animais , Evolução Fatal , Humanos , MasculinoRESUMO
Despite the great number of spiders in the world, only a small group of them is capable of producing death in humans. In Argentina, there are only three of the four genera of spiders considered of high risk to humans: Latrodectus is present in rural areas, Phoneutria is restricted to small regions while Loxosceles is distributed throughout the country. Accidents by Loxosceles represent around 4% of the total number produced by venomous animals in Argentina. The bite is accidental and may produce considerable local necrosis with scar formation and ulcers of slow and difficult healing that may require surgical repair. Some bitten people may suffer from intravascular hemolysis, disseminated coagulation and acute renal insufficiency leading to death. Despite the great number of studies performed on Loxosceles venoms, at present, the physiopathological course of poisoning is not clear and there is not common criteria for its treatment. In this review, biological and epidemiological data of this spider are described as well as the venom composition and the possible participation of its components in the poisoning. These data provide biological and biochemical tools to understand the course of poisoning and to have better criteria for the treatment and prevention of these accidents and their complications.
Assuntos
Diester Fosfórico Hidrolases/intoxicação , Picada de Aranha , Venenos de Aranha/intoxicação , Animais , Argentina/epidemiologia , Humanos , Picada de Aranha/diagnóstico , Picada de Aranha/tratamento farmacológico , Picada de Aranha/epidemiologia , Aranhas/anatomia & histologiaRESUMO
Despite the great number of spiders in the world, only a small group of them is capable of producing death in humans. In Argentina, there are only three of the four genera of spiders considered of high risk to humans: Latrodectus is present in rural areas, Phoneutria is restricted to small regions while Loxosceles is distributed throughout the country. Accidents by Loxosceles represent around 4 percento of the total number produced by venomous animals in Argentina. The bite is accidental and may produce considerable local necrosis with scar formation and ulcers of slow and difficult healing that may require surgical repair. Some bitten people may suffer from intravascular hemolysis, disseminated coagulation and acute renal insufficiency leading to death. Despite the great number of studies performed on Loxosceles venoms, at present, the physiopathological course of poisoning is not clear and there is not common criteria for its treatment. In this review, biological and epidemiological data of this spider are described as well as the venom composition and the possible participation of its components in the poisoning. These data provide biological and biochemical tools to understand the course of poisoning and to have better criteria for the treatment andon
Assuntos
Humanos , Animais , Picada de Aranha/diagnóstico , Picada de Aranha/tratamento farmacológico , Picada de Aranha/epidemiologia , Diester Fosfórico Hidrolases/intoxicação , Venenos de Aranha/intoxicação , Argentina , Aranhas/anatomia & histologiaRESUMO
Loxoscelism, the term used to describe lesions and clinical manifestations induced by brown spider's venom (Loxosceles genus), has attracted much attention over the last years. Brown spider bites have been reported to cause a local and acute inflammatory reaction that may evolve to dermonecrosis (a hallmark of envenomation) and hemorrhage at the bite site, besides systemic manifestations such as thrombocytopenia, disseminated intravascular coagulation, hemolysis, and renal failure. The molecular mechanisms by which Loxosceles venoms induce injury are currently under investigation. In this review, we focused on the latest reports describing the biological and physiopathological aspects of loxoscelism, with reference mainly to the proteases recently described as metalloproteases and serine proteases, as well as on the proteolytic effects triggered by L. intermedia venom upon extracellular matrix constituents such as fibronectin, fibrinogen, entactin and heparan sulfate proteoglycan, besides the disruptive activity of the venom on Engelbreth-Holm-Swarm basement membranes. Degradation of these extracellular matrix molecules and the observed disruption of basement membranes could be related to deleterious activities of the venom such as loss of vessel and glomerular integrity and spreading of the venom toxins to underlying tissues.