Aranhas de interesse médico no Brasil / Spiders of medical interest in Brazil

O documento apresenta informações sobre aranhas de importância médica no Brasil. Descreve a estrutura externa das aranhas e destaca três gêneros de importância em saúde pública: aranha-marrom (Loxosceles), aranha-armadeira ou macaca (Phoneutria) e viúva-negra (Latrodectus). Traz imagens dessas espécies e lista sinais, sintomas e tratamento para acidentes com elas. Apresenta dados de série histórica de acidentes por aranhas no Brasil e Tocantins entre 2000-2022. Por fim, traz recomendações sobre prevenção e primeiro atendimento para acidentes com aranhas.

The document provides information on medically significant spiders in Brazil. It describes the external structure of spiders and highlights three genera of public health importance: brown recluse spider (Loxosceles), wandering spider or macaque spider (Phoneutria), and black widow spider (Latrodectus). It includes images of these species and lists signs, symptoms, and treatment for accidents involving them. It presents historical data on spider-related accidents in Brazil and Tocantins between 2000-2022. Finally, it provides recommendations for prevention and initial first aid for spider bites.

El documento proporciona información sobre arañas de importancia médica en Brasil. Describe la estructura externa de las arañas y destaca tres géneros de importancia para la salud pública: la araña de rincón (Loxosceles), la araña errante o araña mono (Phoneutria) y la viuda negra (Latrodectus). Incluye imágenes de estas especies y enumera los signos, síntomas y tratamiento para accidentes con ellas. Presenta datos históricos sobre accidentes relacionados con arañas en Brasil y Tocantins entre 2000 y 2022. Por último, proporciona recomendaciones para la prevención y la atención de primeros auxilios en caso de picaduras de araña.

Gene cloning, heterologous expression and activity identification of latroeggtoxin-Ⅵ / 生物工程学报

One of the distinct characters of Latrodectus tredecimguttatus is that its toxic components exist not only in the venomous glands, but also in the tissues outside the venomous glands and even in the eggs. Investigation on the toxins outside the venomous glands can deepen our understanding of spider toxins and discover new lead molecules with important application prospects. In order to explore the low-abundance proteinaceous toxins in the L. tredecimguttatus eggs, we used bioinformatic strategies to mine a gene sequence encoding a peptide toxin from the transcriptome of L. tredecimguttatus eggs, and then heterologously expressed the gene successfully with a 3'-RACE combined with nest PCR strategy. Biological activity analyses indicated that the expressed peptide toxin, named latroeggtoxin-Ⅵ (LETX-Ⅵ), could inhibit Na⁺ channel currents in ND7/23 cells and promote dopamine release from PC12 cells, without obvious toxicity against Periplaneta americana and bacteria as well as fungi including Staphylococcus aureus and Candida albicans, demonstrating that LETX-Ⅵ is a mammal-specific neurotoxin with a potential application prospect in development of the tool reagents for neurobiological study and the drugs for treating related diseases.

Widow spiders in the New World: a review on Latrodectus Walckenaer, 1805 (Theridiidae) and latrodectism in the Americas

Humankind has always been fascinated by venomous animals, as their toxic substances have transformed them into symbols of power and mystery. Over the centuries, researchers have been trying to understand animal venoms, unveiling intricate mixtures of molecules and their biological effects. Among venomous animals, Latrodectus Walckenaer, 1805 (widow spiders) have become feared in many cultures worldwide due to their extremely neurotoxic venom. The Latrodectus genus encompasses 32 species broadly spread around the globe, 14 of which occur in the Americas. Despite the high number of species found in the New World, the knowledge on these spiders is still scarce. This review covers the general knowledge on Latrodectus spp. from the Americas. We address widow spiders' taxonomy; geographical distribution and epidemiology; symptoms and treatments of envenomation (latrodectism); venom collection, experimental studies, proteome and transcriptome; and biotechnological studies on these Latrodectus spp. Moreover, we discuss the main challenges and limitations faced by researchers when trying to comprehend this neglected group of medically important spiders. We expect this review to help overcome the lack of information regarding widow spiders in the New World.(AU)

Latrodectismo en la provincia de Jujuy: Aspectos epidemiológicos y clínicos / Latrodectism in the province of Jujuy: Epidemiological and clinical aspects

En Argentina, las especies de arañas de importancia sanitaria pertenecen a los géneros Loxosceles, Phoneutria y Latrodectus. El objetivo del presente trabajo fue relevar los accidentes producidos por el género Latrodectus atendidos en el centro de referencia y derivación provincial de animales venenosos de Jujuy (Hospital San Roque) en el período: 1 de enero de 1998 al 31 de diciembre de 2014. En los diecisiete años analizados se registraron 30 historias clínicas con diagnóstico de latrodectismo, el 83 % de los casos procede de zonas semiáridas y áridas de la provincia de Jujuy. Se registró un valor medio de 1.8 casos/año; la mayoría de los accidentados (63 %) fueron de sexo masculino y la franja etaria más afectada se ubicó entre 16-25 años (50 %). La visualización del arácnido fue confirmada por 18 pacientes, de los cuales el 67 % (n=12) lo identificó como "huayruro" o "viuda negra". Entre las manifestaciones clínicas predominaron: dolor local, dolor generalizado, dolor abdominal, diaforesis e hipertensión arterial. El periodo de internación fue corto (2,7 días) y no hubo complicaciones ni óbitos. Este es el primer estudio clínico-epidemiológico de latrodectismo en el noroeste argentino.

In Argentina, the species of spiders of sanitary importance belong to the Loxosceles, Latrodectus and Phoneutria genera. The objective of this study was to survey accidents caused by the spiders of Latrodectus genus treated at the Jujuy provincial venomous animal reference and referral center (San Roque Hospital) between January 1, 1998 and December 31, 2014. In the seventeen years analyzed, 30 medical records with a diagnosis of latrodectism were analyzed, 83% of the cases came from semi-arid and arid areas of the province of Jujuy. An average of 1.8 cases/year was established. Most of the injured (63%) were male and the most affected age group was between 16-25 years (50%). The arachnid depiction was confirmed by 18 patients, of which 67% (n=12) identified it as "huayruro" or "black widow". Predominant clinical manifestations were local pain, generalized pain, abdominal pain, diaphoresis and hypertension. The length of hospitalization was short (2,7 days) and there were no complications or deaths. This is the first clinical-epidemiological study of latrodectism in northwestern Argentina

First report of brown widow spider sightings in Peninsular Malaysia and notes on its global distribution

Background:The brown widow spider (Latrodectus geometricus Koch, 1841) has colonised many parts of the world from its continent of origin, Africa. By at least 1841, the species had successfully established populations in South America and has more recently expanded its range to the southern states of North America. This highly adaptable spider has been far more successful in finding its niche around the world than its famous cousins, the black widow, Latrodectus mactans, found in the south-eastern states of North America, and the red-back, Latrodectus hasselti, found mostly in Australia, New Zealand and Japan.Methods:We performed an extensive web search of brown widow sightings and mapped the location of each sighting using ArcGIS. Specimens reputedly of the species L. geometricus were collected at three localities in Peninsular Malaysia. The spiders were identified and documented based on an examination of morphological characteristics and DNA barcoding.Results:The spiders found in Peninsular Malaysia were confirmed to be Latrodectus geometricus based on their morphological characteristics and DNA barcodes. We recorded 354 sightings of the brown widow in 58 countries, including Peninsular Malaysia.Conclusion:Reports from the Americas and the Far East suggest a global-wide invasion of the brown widow spider. Herein we report the arrival of the brown widow spider in Peninsular Malaysia and provide notes on the identification of the species and its recently expanded range.(AU)

Physiological and biochemical characterization of egg extract of black widow spiders to uncover molecular basis of egg toxicity

BACKGROUND: Black widow spider (L. tredecimguttatus) has toxic components not only in the venomous glands, but also in other parts of the body and its eggs. It is biologically important to investigate the molecular basis of the egg toxicity. RESULTS: In the present work, an aqueous extract was prepared from the eggs of the spider and characterized using multiple physiological and biochemical strategies. Gel electrophoresis and mass spectrometry demonstrated that the eggs are rich in high-molecular-mass proteins and the peptides below 5 kDa. The lyophilized extract of the eggs had a protein content of 34.22% and was shown to have a strong toxicity towards mammals and insects. When applied at a concentration of 0.25 mg/mL, the extract could completely block the neuromuscular transmission in mouse isolated phrenic nerve-hemidiaphragm preparations within 12.0 ± 1.5 min. Using whole-cell patch-clamp technique, the egg extract was demonstrated to be able to inhibit the voltage-activated Na+, K+and Ca2+ currents in rat DRG neurons. In addition, the extract displayed activities of multiple hydrolases. Finally, the molecular basis of the egg toxicity was discussed. CONCLUSIONS: The eggs of black widow spiders are rich in proteinous compounds particularly the high-molecular-mass proteins with different types of biological activity The neurotoxic and other active compounds in the eggs are believed to play important roles in the eggs' toxic actions.

Recent progress in protein chemistry and proteomics of Latrodectus tredecimguttatus toxins / 生物工程学报

Latrodectus tredecimguttatus (commonly known as black widow spiders) have toxins not only in their venom glands, but also in other parts of their body, in their eggs and even in the newborn spiderlings. The study on the toxins in venom and materials outside the venom glands of the spiders to elucidate their differences and similarities, evolutional relationship and biological functions is of important theoretical and applicable significance. The development of modern protein chemistry and proteomics techniques has provided efficient means for the study of protein and peptide toxins of L. tredecimguttatus. By using such techniques, the molecular base and action mechanism of the toxins can be revealed at the levels of both single purified proteins and omics. Up to now, although protein chemistry and proteomics study on L. tredecimguttatus toxins have achieved a certain progress, the relevant work particularly that on the toxins in the materials outside the venom glands has to be further deepened.

Molecular characterization, electrophysiological and contraceptive effect of chilean latrodectus venom / Caracterización molecular, electrofisiológica y efecto anticonceptivo del veneno de latrodectus chilena

Since the 1970s, There have been studies of the venom of Latrodectus sp. spiders, in particular the latrotoxin (LTX) of Latrodectus mactans. Many of the studies were aimed at understanding the action of the venom on the muscular system. Now accepted that LTX is able to generate a calcium-permeable membrane pore and modulate the release of synaptic vesicles that activate a receptor and induce cellular changes. Interestingly, when work began with venom obtained from the Latrodectus sp present in Chile, it generated clinical indications similar to the bite of this spider in another country, with some differences in intensity. The purpose of the first studies was to understand the systemic mechanisms of this venom, and other active compounds were studied for biological interest. It was found that these molecules are capable of causing systemic effects such as changes in muscle contraction; of generating vascular relaxation and synaptic and cellular modulation; and of altering potassium conductance channels. Based on this evidence, we suggested biotechnological applications to characterize low molecular-weight compounds obtained from the Chilean Latrodectus venom and exploring the effects on the electrophysiology in oocytes and neurons, and the contraceptive effect on spermatozoa.

Desde los años 70, se han realizado estudios con el veneno de arañas Latrodectus sp, en particular la latrotoxina (LTX) de Latrodectus mactans. Muchos de estos estudios estuvieron enfocados a entender la acción del veneno sobre el sistema muscular. Hoy en día es aceptado que la LTX es capaz de generar un poro de membrana permeable a calcio y modular la liberación de vesículas sinápticas que activan un receptor e inducen cambios celulares. Interesantemente, cuando comenzamos a trabajar con el veneno obtenido de Latrodectus sp. presente en Chile, ésto generó indicaciones clínicas similares a la picadura de esta araña en otros países, con algunas diferencias en su intensidad. El propósito de estos primeros estudios fue entender los mecanismos sistémicos de este veneno y además otros compuestos activos fueron estudiados para interés biológico. Se ha encontrado que estas moléculas son capaces de causar efectos sistémicos así como cambios en la contracción muscular; generar relajación vascular y modulación sináptica y celular; y de alterar los canales de conductancia de potasio. Basados en estas evidencias, nosotros sugerimos usar aplicaciones biotecnológicas para caracterizar los compuestos de bajo peso molecular obtenidos del veneno de Latrodectus Chilena y explorar los efectos sobre la electrofisiología en ovocitos y neuronas, y el efecto anticonceptivo sobre los espermatozoides.

Neurotoxic activity and ultrastructural changes in muscles caused by the brown widow spider Latrodectus geometricus venom / Actividad neurotóxica y cambios ultraestructurales en musculos causados por el veneno de la araña viuda marrón Latrodectus geometricus

Brown widow spider (Latrodectus geometricus) venom (BrWSV) produces few local lesions and intense systemic reactions such as cramps, harsh muscle pains, nausea, vomiting and hypertension. Approximately 16 protein bands under reducing conditions and ~ 14 bands under non-reducing conditions on a 12.5% sodium dodecyl sulfate-polyacrylamide gel electrophoresis were observed. Neurotoxic clinical manifestations were confirmed in vivo, while proteolytic activity was demonstrated on gelatine film. Severe ultrastructural damages in mice skeletal muscles were observed at 3, 6, 12 and 24 h postinjection with at total of 45 µg of venom protein. Infiltration of eosinophils and ruptures of the cellular membranes were observed in the muscles along with swelling of the nuclear cover and interruption of the collagen periodicity. Altered mitochondrias and autophage vacuoles, nuclear indentation and mitochondria without cristae, slight increment of intermyofibrillar and subsarcolemic spaces and myelinic figures formation were also observed. In the capillary, endothelial membrane unfolding into the lumen was noticed; along with myelinic figures compatible with a toxic myopathy. Swollen sarcotubular systems with lysis of membrane, intense mitochondria autophagia and areas without pinocytic vesicles were observed. Swollen mitochondria surrounded by necrotic areas, myofibrillar disorganization and big vacuolas of the sarcotubular system, degenerated mitochondrium with formation of myelinic figure was seen. Glycogenosomes with small particulate, muscle type glycogen was noticed. Autophagic vacuole (autophagolysosomes) and necrotic areas were also noticed. These damages may be due to interactive effects of the multifactorial action of venom components. However, Latrodectus geometricus venom molecules may also be utilized as neuro therapeutic tools, as they affect neuronal activities with high affinity and selectivity. To our knowledge, the present study...

El veneno de la araña viuda marrón (Latrodectus geometricus) produce pocas lesiones locales pero intensas reacciones sistémicas, tales como calambres, dolores musculares severos, nauseas, vómitos e hipertensión arterial. Se observaron ~ 16 bandas de proteina bajo condiciones reducidas y ~14 bandas bajo condiciones no reducidas en electroforesis en geles de poliacrilamida al 12.5%. Las manifestaciones neurotóxicas clínicas fueron confirmadas in vivo, mientras que la actividad proteolítica fue demostrada en una placa de gelatina. Los músculos de ratón se estudiaron durante las 3, 6, 12 y 24 horas después de ser inyectados con 45 µg de proteina de veneno. Los músculos fueron seriamente dañados por este veneno. Se demostró una infiltracción de células eosinofílicas y rupturas de membranas celulares en tejido muscular, al mismo tiempo un fuerte incremento de la membrana nuclear y una interrupción de la periodicidad del colágeno. Se observaron daños en la mitocondria y sin cristaes, vacuolas autofágicas e indentación nuclear. Se notó un aumento de la luz de los espacios intermiofibrilares y subsarcolemicos. En los capilares fue visible un desdoblamiento de la membrana endotelial hacia el lúmen vascular. Del mismo modo, fue visto un hinchamiento del sistema sarcotubular con lisis de las membranas; intensa autofagia de mitocondrias y áreas sin vesículas pinocíticas. Fue además observado, glucogenosomas con glucogeno particulado. Se observaron vacuolas autofágicas (autofagolisosomas) y áreas de necrosis. Estos daños podrían ser atribuídos a los efectos interactivos de una acción multifactorial de los componentes del veneno.

Envenomation caused by Latrodectus geometricus in São Paulo state, Brazil: a case report

Widow spiders (Latrodectus spp.), also known as "black widows", have a worldwide distribution and can cause latrodectism. To the best of our knowledge, in Brazil, only one case of Latrodectus geometricus (Koch, 1841) envenomation in a human has been reported. The aim of the present report is to describe a spider bite caused by Latrodectus geometricus in a patient who lives in Paranapanema, São Paulo state, Brazil.(AU)

First case of human latrodectism in Venezuela / Primeiro caso de latrodectismo humano na Venezuela

The first case of envenoming by Latrodectus geometricus in Venezuela is described. The accident occurred at the victim’s home, in Aragua de Barcelona, Anzoátegui State. The 31-year-old female victim was bitten twice on the left scapular region, in quick succession (within seconds). She developed a hyperactive state of the central, autonomic and peripheral nervous systems with minor local symptoms.

Descreve-se o primeiro caso de envenenamento por Latrodectus geometricus na Venezuela. O acidente ocorreu na residência, em Aragua de Barcelona, Estado Anzoátegui. A paciente de 31 anos de idade foi picada, consecutivamente duas vezes, em segundos, na região escapular esquerda. Ela desenvolveu um quadro de hiperatividade do sistema nervoso central, autonômico e periférico com escassa sintomatologia local.

Envenenamiento en niños por mordedura de la araña Latrodectus Mactans (Viuda Negra): características clínicas y tratamiento / Poisoning caused by Latrodectus Mactans (Black Widow) spider bite among children: clinical features and therapy

Introducción: El envenenamiento por mordedura de araña viuda negra es poco frecuente en edades pediátricas sin embargo no está exento de complicaciones y si no se trata a tiempo puede causar la muerte. En México se desconoce el número exacto de estos accidentes. Objetivo: Identificar los signos y síntomas característicos, evolución y tratamiento de los niños atendidos por morderua de araña en el Hospital Infantil del Estado de Sonora, con el propósito de establecer el tratamiento oportuno. Material y Métodos: Se revisaron 43 expedientes de niños hospitalizados por mordedura de araña viuda negra entre 1978-2004, las variables consideradas fueron: edad, género, lugar de origen, sitio del accidente, área corporal afectada, tratamiento previo; grado de envenenamiento por signos y síntomas, tratamiento, evolución clínica. Resultados: Predominó el género masculino 69.7%; sin diferencias entre el número de menores de seis años, escolares y adolescentes. El 44 y 37% de los casos se presentaron en el verano y en horas de la tarde, respectivamente. El 74% de los pacientes tuvieron el contacto con el arácnido dentro del domicilio; las áreas anatómicas más afectadas fueron, miembros superiores y tronco; los signos y síntomas más notables en lactantes y preescolares fueron: irritabilidad, llanto constante, sialorrea, agitación, eritema en área de lesión convulsiones. En escolares y adolescentes fueron los signos y sínotmas dolor en sitio de lesión, dolor abdominal, dolor torácico, ansiedad, espasmos musculares y temblor fino. Los pacientes que recibieron tratamiento con faboterapia específica tuvieron mejor evolución y menor tiempo de hospitalización, cabe señalar que no se presentó mortalidad. Conclusiones: La adecuada identificación de los signos y síntomas ocasionados por la morderura de araña en lactantes y preescolares permite el diagnóstico oportuno y ofrece la mejor alternativa de tratamiento.

INTRODUCTION: Poisoning caused by black widow spider bite, is not commonly observed during childhood, it is not exempt from complications, and must be treated in time or the patient can die. In Mexico we do not have accurate data on the exact number of accidents due to this condition. OBJECTIVE: Identify the signs and characteristic symptoms of children treated at the Children's Hospital from the state of Sonora with the aim of starting early treatment. MATERIAL AND METHODS: We reviewed 43 clinical records of hospitalized patients admitted for black widow spider bite between 1978 - 2004. Demographic variables were: age, gender, place of origin, place where accident took place, treatment given prior to hospital admittance, degree of envenomation measured by signs and symptoms, treatment and clinical evolution. RESULTS: 69.7% of cases were male, we did not find differences in the number of patients between infant, pre-school, elementary school children and teenagers. During summer and afternoon hours we registered 44% and 37% cases respectively; 74% patients were poisoned by the spider at home; the anatomical areas most affected were: arms, hands and thorax. Signs and symptoms in infants were: irritability, constanty cry, sialorrea, agitation erythema on wounded areas and seizures. Among elementary school children and teenagers signs included pain in wounded area, abdominal and thoracic, muscle spasms, fine tremor and residual signs. Patients who received fabotherapic treatment had better evolution and less time of hospitalization. No deaths were reported. CONCLUSIONS: The different signs and symptoms between infants, preschool, elementary school children and teenagers allowed us to clearly identify evenommation and differentiate it form confounding diseases. In our study, specific fabotherapy constituted the best treatment choice.

Veneno de Latrodectus mactans de Chile (Araneae, Theridiidae): su efecto sobre músculo liso / Venom of Latrodectus mactans from Chile (Araneae, Theridiidae): effect on smooth muscle

The venoms of Latrodectus sp. have been reported to induce contraction probably mediated by adrenergic and cholinergic transmitters. We have demonstrated that the venom of Chilean Latrodectus mactans contains neurotoxins that induce a contraction partially independent of transmitters release. Transmembrane mobility of Na+ and Ca2+ ions and more specifically, the increase of cytoplasmic calcium concentration are responsible for tonic contraction in smooth muscle. Calcium may enter the cell by several ways, such as the voltage-dependent Ca2+ L-type channels and the Na+/Ca2+ exchanger. This study aimed to examine the participation of this exchanger in the tonic contraction of smooth muscle in vas deferent of rat induced by the venom of the Chilean spider L. mactans. Blockers of Na+ channels (amiloride) and Ca2+ L-type channels (nifedipine), and a stimulator of the exchanger (modified Tyrode, Na+ 80 mM) were used. Simultaneously, variations of the cytoplasmic concentration of Ca2+ were registered by microfluorimetry (Fura-2 indicator) in the presence of nifedipine. In presence of amiloride, dose-dependent inhibition of venom-induced contraction was observed, suggesting the participation of voltage-dependent Ca2+ L-type channels. The contraction was only partially inhibited by nifedipine and the Ca2+ cytoplasmic concentration increased, as assessed by the microfluorimetric registration. Finally, the venom-induced contraction increased in the presence of modified Tyrode, probably due to the action of the Na+/Ca2+ exchanger. Taken together, our results support the idea that the Na+/Ca2+ exchanger is active and may be, at least in part, responsible for the contraction induced by the venom of Chilean L. mactans.

Abdomen agudo por picadura de viuda negra. Evaluación clínica, diagnóstica y terapéutica: análisis descriptivo - retrospectivo. Presentación de un caso interpretado como abdomen agudo quirúrgico / Acute abdomen by black widow spider bite. Clinical, diagnostic and therapeutic evaluation: descriptive - retrospective analysis. Presentation of a case interpreted as acute surgical abdomen

Antecedentes: el abdomen agudo médico por picadura de Latrodectus Mactans es una patología poco frecuente, con una típica presentación clínica. Se presenta como un cuadro neurotóxico (hiperestesia, fasciculaciones, contracturas musculares generalizadas, excitabilidad, hiperreflexia); y en casos graves síntomas muscarínicos: miosis, bradicardia, HTA. Por las contracturas abdominales puede ser interpretado como abdomen agudo quirúrgico. Objetivo: evaluación clínica, diagnóstica y terapéutica de abdomen agudo por picadura de Latrodectus Mactans de un caso interpretado como abdomen agudo quirúrgico. Diseño: estudio observacional descriptivo restrospectivo. Población: un paciente de sexo masculino de 31 años de edad. Método: análisis de historia clínica de un paciente que consulta por dolor abdominal de tipo cólico, posterior a una transgresión alimentaria e ingesta abundante de alcohol. Examen físico: dolor a la palpación sin defensa ni peritonismo. Se interpreta como cólico intestinal medicándose con espasmódicos. Pasadas 2 horas presenta vómitos y vientre en tabla; por lo cual se deriva a este hospital, con diagnóstico de abdomen agudo perforativo. Laboratorio: leucocitosis con desviación a la izquierda. Se interpreta abdomen agudo quirúrgico y se laparotomiza. Resultado: laparotomía: distensión de colon e intestino delgado sin causa orgánica. Postoperatorio presenta HTA, bradicardia, diaforesis, edema facial, y contractura muscular generalizada. Reinterrogatorio: refiere sensación quemante en región epigástrica previo al inicio del cuadro (¿picadura?). Se sospecha Lactrodesis iniciándose tratamiento médico, con remisión absoluta de la sintomatología en 12 hs. Conclusión: el cuadro de Lactrodesis presenta una clínica típica, que no debe ser mal interpretada. Es importante ser sumamente cauto en la anamnesis (lugar de procedencia), el examen físico (buscar lesiones por picadura) y la clínica; y tener presente en los cuadros de abdomen agudo dicha patología

Latrodectismo / Latrodectism

Numerosas especies de artrópodos poseen veneno capaz de producir enfermedad en el ser humano. Por su severidad y frecuencia, debe destacarse la causa por arácnidos (aracnidismo), especialmente la producida por el género Latrodectus (Orden Araneida), capaz de desencadenar un cuadro neurotóxico grave, denominado latrodectismo. En este artículo se revisan los aspectos biológicos, clínicos y terapéuticos más relevantes de esta patología

Edema palpebral severo en latrodectismo / Severe palpebral edema in lactredectus

Se presentan tres casos de pacientes que acudieron por latrodectismo y que desarrollaron edema palpebral severo durante su hospitalización. El veneno de la araña latrodectus mactans despolariza las membranas sinápticas, por apertura iónica no específica de los canales de calcio. La despolarización promueve la liberación de neurotransmisores calcio independientes e inhibe de recaptación. Estos datos podrían explicar en parte el edema palpebral desde un punto de vista neurogénico.

Estudo retrospectivo de latrodectismo na Bahia, Brasil / Retrospective study on Latrodectus stings in Bahia, Brazil

O trabalho apresenta um estudo retrospectivo de setenta e sete casos de latrodectismo no Estado da Bahia, Brasil, de agosto de 1980 a julho de 1990. Os dados foram levantados nos livros de registro e arquivo de fichas do CIAVE. O agente etiológico em 28 por cento dos acidentes aracnídeos foi a espécie L. curacaviensis e a maior incidência foi registrada no meio urbano (57 por cento), em indivíduos do sexo masculino (7O por cento) e faixa etária de 10 a 29 anos (58 por cento). Os principais sinais locais foram dor (56 por cento), pápula eritematosa (2l por cento) e edema discreto (l7 por cento), e os sistêmicos foram dor em membros inferiores (29 por cento), tremores e contraturas (29 por cento), sudorese (28 por cento) parestesia em membros (21 por cento) e dor abdominal (17 por cento). O tratamento foi sintomático em 67 por cento dos casos e específico em 21 por cento. O tempo de permanência hospitalar após o uso do soro antilatrodectus foi menor que 24 boras em 64 por cento dos casos.