RESUMEN
CONTEXT: In recent years, the Noble false widow spider Steatoda nobilis (Thorell, 1875) has expanded its range globally and may represent a potential threat to native ecosystems and public health. Increasing numbers in synanthropic habitats have led to more human encounters and envenomations. Steatoda nobilis bites were previously classed as medically significant with similarities to bites from true black widows of the genus Latrodectus but deemed milder in onset, with symptoms generally ranging from mild to moderate. CASE DETAILS: In this manuscript we present 16 new cases of S. nobilis envenomations bringing the total number of confirmed cases reported in the literature to 24. We report new symptoms and provide discussion on the contributing factors to pathology following bites by S. nobilis. DISCUSSION: We report a range of pathologies including necrosis, Latrodectus-like envenomation symptoms that include debilitating pain, tremors, fatigue, nausea, hypotension, and vectored bacterial infections including cellulitis and dermatitis. Symptoms ranged from mild to severe, requiring hospitalisation in some cases.
Asunto(s)
Infecciones Bacterianas , Araña Viuda Negra , Picaduras de Arañas , Venenos de Araña , Arañas , Animales , Ecosistema , Humanos , Picaduras de Arañas/diagnóstico , Picaduras de Arañas/patología , Venenos de Araña/toxicidadRESUMEN
Spiders have long been admired for the beauty of their webs. They are celebrated in popular culture as well as in medical eponyms. This contribution provides the historical background for three spider-related eponyms: nevus araneus (spider angioma), arachnodactyly, and the arachnoid mater. Nevus araneus was first named and described by Sir Erasmus Wilson in 1842. Arachnodactyly was described in 1896 by Antoine Marfan using the term pattes d'araignée, which means spider legs. In 1902, Emile Charles Achard proposed the term arachnodactyly for this clinical finding. The arachnoid mater had been named in 1699 by Frederik Ruysch. The clinical management of spider bites from the only two dangerous venomous spiders within the United States, the black widow spider (Latrodectus mactans) and the brown recluse spider (Loxosceles reclusa), is reviewed.
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Aracnodactilia , Aracnoides , Epónimos , Nevo , Arañas , Animales , Aracnodactilia/patología , Araña Viuda Negra , Araña Reclusa Parda , Humanos , Nevo/patología , Picaduras de Arañas/patologíaAsunto(s)
Picaduras de Arañas/diagnóstico , Picaduras de Arañas/terapia , Analgésicos/administración & dosificación , Animales , Antivenenos/administración & dosificación , Benzodiazepinas/administración & dosificación , Araña Viuda Negra , Antagonistas de los Receptores Histamínicos/administración & dosificación , Humanos , Índice de Severidad de la Enfermedad , Picaduras de Arañas/patología , Venenos de Araña/toxicidad , Toxoide Tetánico/administración & dosificaciónRESUMEN
BACKGROUND: Bites by Loxosceles spiders (also known as recluse spiders or brown spiders) can cause necrotic ulcerations of various sizes and dimensions. The current standard of care for brown spider bites includes analgesics, ice, compression, elevation, antihistamines, and surgical debridement. Hyperbaric oxygen therapy (HBOT) in the treatment of brown spider bites has been administered in the early stage of ulceration, or 2 to 6 days after the bite. Unfortunately, the diagnosis of spider bite-related ulcers is often delayed and weeks or months may elapse before HBOT is considered. OBJECTIVE: To evaluate the effect of HBOT on nonhealing wounds caused by brown spider bites in the late, chronic, nonhealing stage. METHODS: Analysis of 3 patients with brown spider-bite healing wounds treated at The Sagol Center for Hyperbaric Medicine and Research in Israel. Patients presented 2 to 3 months after failure of other therapies including topical dressings, antibiotics, and corticosteroids. All patients were treated with daily 2 ATA (atmospheres absolute) with 100% oxygen HBOT sessions. RESULTS: All 3 patients were previously healthy without any chronic disease. Their ages were 30, 42, and 73 years. They were treated once daily for 13, 17, and 31 sessions, respectively. The wounds of all 3 patients healed, and there was no need for additional surgical intervention. There were no significant adverse events in any of the patients. CONCLUSIONS: Microvascular injury related to brown spider bites may culminate in ischemic nonhealing wounds even in a relatively young, healthy population. Hyperbaric oxygen therapy should be considered as a valuable therapeutic tool even months after the bite.
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Oxigenoterapia Hiperbárica , Picaduras de Arañas/terapia , Adulto , Anciano , Animales , Araña Reclusa Parda , Femenino , Humanos , Masculino , Picaduras de Arañas/patología , Cicatrización de HeridasRESUMEN
Black widow spiders are found throughout the continental United States and north into the southern Canadian provinces. Male black widow spiders are of little medical importance. Female black widow spiders can be 20 times larger than males. The female can be identified by the hourglass pattern, red or orange in color, on the ventral aspect of her shiny, globose black abdomen. Black widow spiders control the amount of venom they inject; an estimated 15% of bites to humans are non-envenomating. Cats are very sensitive to the venom and deaths are common. Dogs have severe clinical signs but are considered more resistant than cats. A single bite is capable of delivering a lethal dose of venom to companion animals. There are several toxic components consisting of five or six biologically active proteins. These include a potent mammalian neurotoxin called alpha-latrotoxin, which induces neurotransmitter release from nerve terminals. Acetylcholine, noradrenalin, dopamine, glutamate, and enkephalin systems are all susceptible to the toxin. Onset of clinical signs usually occurs during the first 8 hours post envenomation. The condition is extremely painful in moderate to severe envenomations. Abdominal rigidity without tenderness is a hallmark sign of Latrodectus envenomation. In cats, paralytic signs may occur early and are particularly marked. Hypertension is a significant threat. First aid is of no value in the treatment. The primary treatment for black widow spider envenomation is the administration of specific antivenin, which provides the most permanent and quickest relief of the envenomation syndrome, usually within 30 minutes of infusion. The prognosis of Latrodectus envenomation is uncertain of several days, and complete recovery may take weeks.
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Antivenenos/uso terapéutico , Araña Viuda Negra , Picaduras de Arañas/veterinaria , Venenos de Araña/envenenamiento , Animales , Enfermedades de los Gatos/tratamiento farmacológico , Enfermedades de los Gatos/etiología , Enfermedades de los Gatos/patología , Gatos , Enfermedades de los Perros/tratamiento farmacológico , Enfermedades de los Perros/etiología , Enfermedades de los Perros/patología , Perros , Femenino , Masculino , Dolor/etiología , Dolor/veterinaria , Factores Sexuales , Picaduras de Arañas/complicaciones , Picaduras de Arañas/tratamiento farmacológico , Picaduras de Arañas/patología , Factores de Tiempo , Resultado del TratamientoRESUMEN
Envenomation from the brown recluse (Loxosceles recluse) spider commonly proceed on one of three clinical pathways. The majority of bites (90%) result in nothing more than a local reaction. They are essentially self-limiting, require little if any attention, and resolve spontaneously. A great majority of the remaining bites will produce necrotic ulcerations of various sizes and dimensions, with systemic sequela ranging from fever to hemolysis and kidney failure. Finally, and in the most rare cases, the patient will succumb a fatal systemic reaction. Current therapeutic options for these wounds remain controversial and include the following: local care, corticosteroids, dapsone, and hyperbaric oxygen (HBO) therapy. This article will review the application of HBO therapy for patients who are envenomated by brown recluse spiders. Information for this manuscript was derived from multiple MEDLINE searches as well as searches of the National Baromedical Service's hyperbaric specialty literature collection.
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Oxigenoterapia Hiperbárica/métodos , Hidrolasas Diéster Fosfóricas/toxicidad , Úlcera Cutánea/terapia , Picaduras de Arañas/terapia , Venenos de Araña/toxicidad , Animales , Humanos , Úlcera Cutánea/patología , Picaduras de Arañas/patologíaRESUMEN
BACKGROUND: Treatment of brown recluse spider bites remains controversial; there are multiple options but little evidence of their effectiveness. METHODS: Over a 5-year period, family physicians enrolled consecutive patients with suspected brown recluse spider bites. Usual care was provided based on physician preferences. Topical nitroglycerine patches and vitamin C tablets were provided at no cost for those who wished to use them. Baseline data were collected, and patients were followed-up weekly until healing occurred. Outcome measures included time to healing and occurrence of scarring. Regression methods were used to evaluate the impact of the 4 main treatment approaches (corticosteroids, dapsone, topical nitroglycerine, and high-dose vitamin C) after controlling for bite severity and other predictors. RESULTS: Two hundred and sixty-two patients were enrolled; outcomes were available for 189. The median healing time was 17 days. Only 21% had permanent scarring. One hundred seventy-four received a single treatment modality. Among this group, 12 different modalities were used. After controlling for other variables, predictors of more rapid healing included lower severity level, less erythema, and less necrosis at time of presentation, younger age, no diabetes, and earlier medical attention. Systemic corticosteroids and dapsone were associated with slower healing. Predictors of scarring were higher severity, presence of necrosis, and diabetes. Dapsone was associated with an increased probability of scarring. CONCLUSIONS: We found no evidence that commonly used treatment approaches reduced healing time or the likelihood of scarring in suspected brown recluse spider bites.
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Antibacterianos/uso terapéutico , Antiinfecciosos/uso terapéutico , Antiinflamatorios/uso terapéutico , Ácido Ascórbico/uso terapéutico , Dapsona/uso terapéutico , Nitroglicerina/uso terapéutico , Atención Primaria de Salud , Picaduras de Arañas/tratamiento farmacológico , Arañas/clasificación , Vasodilatadores/uso terapéutico , Cicatrización de Heridas , Administración Cutánea , Administración Oral , Adulto , Anciano , Animales , Antiinfecciosos/administración & dosificación , Antiinflamatorios/administración & dosificación , Ácido Ascórbico/administración & dosificación , Niño , Dapsona/administración & dosificación , Femenino , Estudios de Seguimiento , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Necrosis , Nitroglicerina/administración & dosificación , Estudios Prospectivos , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Picaduras de Arañas/diagnóstico , Picaduras de Arañas/patología , Vasodilatadores/administración & dosificaciónAsunto(s)
Araña Viuda Negra , Miocarditis/etiología , Picaduras de Arañas , Enfermedad Aguda , Adulto , Animales , Autopsia , Ecocardiografía , Femenino , Humanos , Unidades de Cuidados Intensivos , Miocarditis/diagnóstico , Miocarditis/mortalidad , Miocarditis/patología , Picaduras de Arañas/complicaciones , Picaduras de Arañas/diagnóstico , Picaduras de Arañas/mortalidad , Picaduras de Arañas/patologíaRESUMEN
Latrodectism is considered dangerous for human beings. Acute renal failure after envenomation is not common and usually results from prerenal failure. We report a 59-y-o man with acute oliguric renal failure due to a combination of prerenal and renal causes after being bitten by a black Latrodectus spider. He had the characteristic anxiety, severe hypertension, tremor, facial edema, and generalized diaphoresis. The patient recovered within a week without sequelae. Clinicians should not overlook the possibility of acute renal failure in latrodectism.
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Lesión Renal Aguda/etiología , Araña Viuda Negra , Picaduras de Arañas/complicaciones , Venenos de Araña/envenenamiento , Lesión Renal Aguda/patología , Animales , Pruebas de Química Clínica , Pruebas Hematológicas , Humanos , Masculino , Persona de Mediana Edad , Picaduras de Arañas/patologíaRESUMEN
STUDY OBJECTIVES: Topical nitroglycerin has been reported to prevent skin necrosis from brown recluse spider bites, but this has never been scientifically tested. This study attempts to assess the effects of topical nitroglycerin on experimental Loxosceles reclusa envenomations. METHODS: We performed a randomized, blinded, controlled study in an animal care facility. Twenty-four New Zealand white rabbits were experimentally envenomated by means of subcutaneous injection with 20 microg of brown recluse spider venom. Rabbits were randomized to 1 of 2 experimental groups. The treatment group received 1 in of 2% topical nitroglycerin ointment every 6 hours for 3 days applied directly to the envenomation site. The control group received the vehicle without nitroglycerin. Gross examination of the lesions and measurements of the areas of the lesions were made daily. Creatine phosphokinase (CPK), blood urea nitrogen, creatinine, hemoglobin, and hematocrit levels were measured on days 0, 5, and 10. Lesions were excised after 10 days and examined by a blinded pathologist, who measured the area of necrosis and quantified inflammation and edema using a standard wound-healing score. For all values, mean values plus SD were determined. All comparisons made over multiple time points were assessed for significance by using a repeated-measures analysis of variance followed by Fisher least significant difference and Scheffé post hoc comparisons. A P value of.05 or less was used to determine significance. The Student's t test was used to compare the means of single measures. Significance was determined by using 95% confidence intervals. Comparisons of total area of necrosis were made with the nonparametric Mann-Whitney U test because of the heavy positive skew of the data. RESULTS: Skin necrosis developed in all animals. Mean values of the lesion area were not significantly different over time between the 2 groups of animals. At day 10, the median area of necrosis was 22.3 cm2 for the treatment group and 15.4 cm2 for the control group (P =.12). The inflammation score was 3.33+/-0.78 for the treatment group and 2.79+/-1.29 for the control group (P < .01). The edema score was 1.25+/-1.28 for the treatment group and 0.98+/-1.10 for the control group (not significantly different). CPK levels increased dramatically in both groups, with the greatest increase in the treatment group. In both groups hemoglobin and hematocrit levels decreased significantly, whereas WBC counts and platelet counts increased significantly, without significant differences between the 2 groups. CONCLUSION: At the dose used in this experiment, topical nitroglycerin did not prevent skin necrosis, increased inflammation score, and increased serum CPK levels. The results of this study do not support the use of topical nitroglycerin in the treatment of L reclusa envenomation and suggest that systemic toxicity could be increased.
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Modelos Animales de Enfermedad , Nitroglicerina/uso terapéutico , Picaduras de Arañas/tratamiento farmacológico , Vasodilatadores/uso terapéutico , Administración Cutánea , Análisis de Varianza , Animales , Nitrógeno de la Urea Sanguínea , Creatina Quinasa/sangre , Creatinina/sangre , Esquema de Medicación , Evaluación Preclínica de Medicamentos , Hematócrito , Hemoglobinas/análisis , Inflamación , Necrosis , Pomadas , Conejos , Distribución Aleatoria , Índice de Severidad de la Enfermedad , Método Simple Ciego , Picaduras de Arañas/sangre , Picaduras de Arañas/clasificación , Picaduras de Arañas/patología , Estadísticas no Paramétricas , Factores de Tiempo , Cicatrización de Heridas/efectos de los fármacosRESUMEN
PURPOSE: To present a photographically documented case of a known brown recluse spider bite to the eyelid. DESIGN: Interventional case report. METHODS: The wound was photographed daily during an 11-day hospitalization and at 1 month and 6 months after the injury. Treatment included canthotomy and cantholysis; administration of dapsone, antibiotics, and steroids; and hyperbaric oxygen therapy. MAIN OUTCOME MEASURES: Clinical presentation and course of a known brown recluse spider bite. RESULTS: Complete recovery with cicatrization at the site of the bite. CONCLUSIONS: We present a case of a brown recluse spider bite to the left lower eyelid with a discussion of management and outcome of this rarely reported injury.
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Lesiones Oculares/etiología , Párpados/lesiones , Picaduras de Arañas/complicaciones , Arañas , Animales , Antiinfecciosos/uso terapéutico , Antiinflamatorios/uso terapéutico , Niño , Dapsona/uso terapéutico , Lesiones Oculares/patología , Lesiones Oculares/terapia , Párpados/patología , Femenino , Humanos , Oxigenoterapia Hiperbárica , Metilprednisolona/uso terapéutico , Picaduras de Arañas/patología , Picaduras de Arañas/terapiaAsunto(s)
Coagulación Intravascular Diseminada/tratamiento farmacológico , Fiebre Hemorrágica Ebola/tratamiento farmacológico , Homeopatía , Picaduras de Arañas , Venenos de Araña/uso terapéutico , Animales , Venenos de Crotálidos/uso terapéutico , Crotalus , Homeopatía/métodos , Humanos , Conejos , Mordeduras de Serpientes/patología , Mordeduras de Serpientes/fisiopatología , Picaduras de Arañas/patología , Picaduras de Arañas/fisiopatología , Venenos de Araña/aislamiento & purificaciónRESUMEN
OBJECTIVES: Loxosceles reclusa (brown recluse) spider bites can produce severe skin lesions that may necessitate extensive surgical repair. This study delineated the effects of hyperbaric oxygen (HBO) therapy on these lesions by performing a prospective controlled animal study. METHODS: After approval by the Institutional Animal Care and Use Committee, 41 New Zealand white rabbits received 64 intradermal injections of 73 microL of raw venom extract mixed with physiologic buffered saline (Dulbecco's solution). Control injections were made with buffer. The animals were divided into 5 groups: 1) venom and no HBO; 2) venom and 1 immediate HBO treatment (100% O2); 3) venom and immediate HBO with 10 treatments (100% O2); 4) venom and then delayed (48 hr) HBO therapy with 10 treatments (100% O2); and 5) venom and immediate hyperbaric treatment with normal inspired PO2 for 10 treatments (8.4% O2). Three animals in group 2 also received a control sodium citrate buffer injection. HBO treatments were at 2.5 atm absolute (ATA) for 90 minutes twice daily. Daily measurements were made of the lesion diameter, and skin blood flow using a laser Doppler probe. RESULTS: There was no significant effect of HBO on blood flow at the wound center or 1-2 cm from the wound center. Standard HBO significantly decreased wound diameter at 10 days (p < 0.0001; ANOVA), whereas hyperbaric treatment with normoxic gas had no effect. Histologic preparations from 2 animals in each group revealed that there were more polymorphonuclear leukocytes in the dermis of all the HBO-treated animals when compared with the venom-alone and sodium-citrate controls. CONCLUSION: HBO treatment within 48 hours of a simulated bite from L. reclusa reduces skin necrosis and results in a significantly smaller wound in this model. The mechanism appears unrelated to augmented local blood flow between treatments.
Asunto(s)
Oxigenoterapia Hiperbárica/métodos , Picaduras de Arañas/terapia , Venenos de Araña/toxicidad , Animales , Necrosis , Estudios Prospectivos , Conejos , Piel/patología , Picaduras de Arañas/patología , Cicatrización de HeridasRESUMEN
OBJECTIVE: To determine whether hyperbaric O2 (HBO), dapsone, or HBO plus dapsone affects lesion size in a swine model of Loxosceles envenomation. METHODS: In a randomized controlled animal laboratory experiment, 32 piglets were assigned to 1 of 4 equal groups. Each piglet received 15 microliters, of purified venom intradermally on day zero. Group 1 received no treatment; group 2 received HBO at 2 atm for 2 hours on days 1-3; group 3 received 50 mg of dapsone orally on days 1-3; and group 4 received dapsone 50 mg orally and HBO at 2 atm for 2 hours on days 1-3. On days 1-7, 14, and 21, an investigator blinded to the treatment groups measured necrosis and induration. Mean necrosis and induration rates were compared using analysis of variance for repeated measures. RESULTS: Comparing groups on any day, no significant difference was noted in necrosis, induration, reduction in necrosis from day 1, or rate of change in lesion size from days 1-7. A difference was seen in the reduction of induration between all 3 treatment groups and the control group on days 7 and 14 only. The sample size permitted a power of 0.8 to detect a 12-mm mean change in lesion size. CONCLUSION: Compared with the control, neither dapsone, HBO, nor the combination of dapsone and HBO reduced necrosis from Loxosceles envenomation on days 3-21. An increase was seen in the rate of reduction in induration between all 3 treatment groups and the control group on days 7-21. However, the magnitude of this effect was clinically insignificant. In this animal model, treatment with either dapsone or HBO or a combination offers little clinical benefit in Loxosceles envenomation.