Utilization of dapsone and hemoglobin in the epithelial skin regeneration therapy of cutaneous loxoscelism: A case report and integrative literature review

ABSTRACT BACKGROUND: Loxosceles spp are arthropods found worldwide. Its bite may produce cutaneous loxoscelism (necrotic or edematous) or cutaneous-visceral loxoscelism. Depending on their severity and location, cutaneous forms are managed with local cold application and systemic administration of antihistamines, corticosteroids, antibiotics, polymorphonuclear inhibitors, and analgesics. OBJECTIVE: This study aimed to report a case of cutaneous loxoscelism and to identify the main dermatological manifestations associated with the Loxosceles spp bite. DESIGN AND SETTING: This case report and literature review was conducted in a Mexican university. METHODS: A detailed report on the medical management of a patient with cutaneous loxoscelism treated at the emergency department of a public hospital was published. Scopus, PubMed, Web of Science, and Google Scholar databases were searched to identify articles reporting cutaneous loxoscelism. The following keywords were used during the database search: "loxoscelism" OR "spider bite," OR "loxosceles" OR "loxosceles species" OR "loxosceles venom" OR "loxoscelism case report" AND "cutaneous" OR "dermonecrotic arachnidism." RESULTS: A 62-year-old female patient with cutaneous loxoscelism was treated with systemic dapsone and local heparin spray. Eighteen studies with 22 clinical cases were included in this systematic review. Of the 22 patients, 12 (54.5%) were men. L. rufescens was the predominant spider species. CONCLUSIONS: The administration of dapsone and heparin for the management of cutaneous loxoscelism demonstrated success in this case, with no sequelae observed. In general, the literature review indicated favorable outcomes in patients treated with antimicrobials and corticosteroids, with continuous healing of skin lesions. SYSTEMATIC REVIEW REGISTRATION: PROSPERO ID CRD42023422424 (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023422424).

Sistema de presión negativa en loxoscelismo cutáneo-visceral. Reporte de un caso

Introducción: Las mordeduras por araña parda pueden manifestarse desde una simple lesión dérmica en el área de la mordedura, hasta formas graves, con falla orgánica múltiple. Caso Clínico: presentamos el caso de una paciente con mordedura por araña parda, quien presenta inicialmente lesiones dérmicas sin necrosis, evolucionando con áreas de necrosis y el desarrollo de síndrome compartimental de extremidad, sepsis, choque séptico y falla renal. Mejora tras manejo intensivo, anti veneno y colocación de terapia de presión negativa (TPN) en herida, conservando la extremidad afectada integra y recuperando la función renal. Discusion: Este caso en particular presenta los tres tipos de manifestaciones que se generan en el loxoscelismo, las cuales son una forma de presentación poco frecuente. El tratamiento con TPN se ha introducido como una terapia poderosa, no farmacológica para ayudar a acelerar el proceso de cicatrización de heridas y puede ser de utilidad en pacientes con mordedura de araña (loxoscelismo).

Introduction: The brown spider bites have the peculiarity of manifesting from a simple skin lesion in the area of the bite, to severe forms, with multiple organic failure. Clinical Case: We present the case of a patient with a brown spider bite, initially presenting dermal lesions without necrosis, evolving with areas of necrosis and the development of compartment syndrome of extremities, sepsis, septic shock and renal failure. Improvement after intensive management and installation in negative pressure therapy wound (NPT), keeping the affected limb integrated and recovering renal function. Discussion: This case in particular presents the three types of manifestations that are generated in loxoscelism, which are a rare form of presentation. The NPT treatment has been introduced as a powerful, non-pharmacological and physical therapy to help accelerate the wound healing process and may be useful in patients with spider bites.

Tratamiento de una lesión primaria por loxoscelismo cutáneo, complicada por infección, con solución electrolizada de superoxidación con pH neutro (SES). Informe de un caso / Treatment of a Primary Lesion of Cutaneous Loxoscelismo, Complicated by Infection, with Neutral Electrolyzed Water (SES). A Case Report

Resumen Las lesiones por loxoscelismo cutáneo pueden complicarse con infecciones concomitantes debido a que el diagnóstico es presuntivo y no existe un esquema de tratamiento específico. Las soluciones electrolizadas de superoxidación de pH neutro (SES) han mostrado ser eficaces en el tratamiento de lesiones cutáneas severas por sus efectos antisépticos y de regeneración del tejido, por lo que podrían ser un método de curación para las lesiones por loxoscelismo cutáneo. Presentamos el caso de un paciente del sexo masculino, de 73 años, cardiópata, diagnosticado con loxoscelismo cutáneo en el tobillo izquierdo que recibió tratamiento convencional de antibióticos, antiinflamatorios, antihistamínicos y analgésicos, y fue dado de alta. Sin embargo, la lesión evolucionó y fue tratada de manera casera con remedios tradicionales; esta se extendió 360° y presentaba exudado fétido al momento en que decidió regresar al hospital. En la clínica de heridas se optó por manejar la lesión en primera instancia con lavados con SES y desbridamiento, seguido de lavados con SES y apósitos de gel SES 3 veces al día, por 3 días, logrando el control de la infección en este tiempo. Posteriormente, con el régimen basado en la aplicación de SES cada 48 horas, se observó la aparición del tejido de granulación al día 7, y la reepitelización en el día 45 de iniciado el abordaje con SES; el cierre total de la lesión se logró el día 67. El esquema de tratamiento basado en el uso de soluciones electrolizadas de superoxidación de pH neutro mostró ser eficaz en el control de la infección y en la inducción del proceso de regeneración del tejido que llevó al cierre de la herida sin complicaciones para el paciente.

Abstract Cutaneous loxoscelism wounds can be complicated by concomitant infections because the diagnosis is presumptive and there is no specific treatment scheme. Neutral electrolyzed water (SES) has been shown to be effective in the treatment of severe skin lesions due to their antiseptic and tissue regeneration effects and could therefore be a healing method for skin loxoscelism lesions. We present the case of a 73-year-old male patient with heart disease, diagnosed with cutaneous loxoscelism in the left ankle, who received conventional treatment of antibiotics, anti-inflammatories, antihistaminics, and analgesics. He was discharged. However, the injury developed and was treated at home with traditional remedies. It extended 360° and presented a fetid exudate at the time he decided to return to the hospital. In the clinic it was decided to manage the lesion in the first instance with washes with SES and debridement, followed by washes with SES and SES gel dressings three times a day for 3 days, achieving control of the infection at that moment. Subsequently, with the regimen based on the application of SES every 48 hours, the appearance of granulation tissue was observed on day 7, and re-epithelialization on day 45 after starting the SES approach, the total closure of the lesion was achieved on day 67. The treatment scheme based on the use of neutral electrolyzed water proved to be effective in controlling the infection and in inducing the tissue-generation process that led to the closure of the wound without complications for the patient.

Factores asociados al conocimiento y medidas preventivas de mordedura de Loxosceles laeta en la población de la Encuesta Nacional de Programas Presupuestales (ENAPRES) en el Perú 2017-2019

Introducción: Las enfermedades metaxénicas y zoonóticas, son consideradas prioridades nacionales de investigación en salud en Perú 2019-2023. De estas, los casos reportados por loxoscelismo han ido aumentando progresivamente. Objetivo: Determinar los factores asociados al conocimiento y medidas preventivas de mordedura de Loxosceles laeta en la población de la ENAPRES en el Perú 2017-2019. Métodos: Estudio de tipo observacional, transversal, analítico y retrospectivo, basado en la información de la ENAPRES. Resultados: Se analizó una muestra total de 285.354 personas. De estas, aquellos con 60 a más años (RPa=1,48; IC95%: 1,45-1,51), los costeños (RPa=1,37; IC95%: 1,33-1,40), las mujeres (RPa=1,12; IC95%: 1,11-1,13), con primaria o secundaria (RPa=1,12; IC95%: 1,09-1,15), con viviendas inadecuadas [techo (RPa=1,07; IC95%: 1,05-1,10), piso (RPa=1,02; IC95%: 1,00-1,04)], se asociaron con mayor posibilidad de tener más conocimiento sobre mordedura de L. laeta. Por otra parte, los encuestados de 60 a más años (RPa=1,49; IC95%: 1,46-1,52), los costeños (RPa=1,39; IC95%: 1,35-1,43), con estudios superiores no universitarios (RPa=1,19; IC95%: 1,15-1,22), las mujeres (RPa=1,13; IC95%: 1,12-1,14) y con viviendas con techos inadecuados (RPa=1,07; IC95%: 1,05-1,10) se asociaron con mayor posibilidad de realizar adecuadas medidas preventivas. En ambas, se halló asociación con el desechar los residuos orgánicos en calle o vía pública (RPa=0,97; IC95%: 0,96-0,99). Conclusiones: Se encontró aquellos factores asociados a conocimientos y a las medidas preventivas de mordedura de L. laeta.

Background: Metaxenic and zoonotic diseases are one of the ten national priorities for health research in Peru 2019-2023. Of these, the cases reported by loxoscelism have been increasing progressively. Aim: To determine the factors associated with the knowledge and preventive measures of Loxosceles laeta bite in the population of the ENAPRES in Peru 2017-2019. Methods: Observational, cross-sectional, analytical and retrospective study, based on information from ENAPRES. Results: A total sample of 285,354 people was analyzed. Of these, those aged 60 or over (PRa=1,48; 95%CI: 1,45-1,51), those from the coast (PRa=1,37; 95%CI: 1,33-1,40), women (PRa=1,12; 95%CI: 1,11-1,13), with primary or secondary education (PRa=1,12; 95%CI: 1,09-1,15), with inadequate housing [ceiling (PRa=1,07; 95%CI: 1,05-1,10), floor (PRa=1,02; 95%CI: 1,00-1,04)], were associated with higher possibility ofhaving more knowledge about L. laeta bite. On the other hand, those aged 60 or over (PRa=1,49; 95%CI: 1,46-1,52), those from the coast (PRa=1,39; 95%CI: 1,35-1,43), with non-university higher education (PRa=1,19; 95%CI: 1,15-1,22), women (PR a=1,13; 95%CI: 1,12-1,14) and with inadequate housing ceilings (PRa=1,07; 95%CI 1,05-1,10) were associated with a greater possibility of taking adequate preventive measures. In both, an association was found between disposing of organic waste on the street or on public roads (RPa=0.97; 95%CI: 0.96-0.99) Conclusions: It were found factors associated with knowledge and preventive for L. laeta bite.

Primer registro de un caso de loxoscelismo cutáneo ocasionado por mordedura de araña violinista (Loxosceles yucatana) en Yucatán, México / First record of a case of cutaneous loxoscelism caused by violin spider (Loxosceles yucatana) bite in Yucatan, Mexico

El loxoscelismo es ocasionado cuando el veneno dermonecrótico producido por las arañas del género Loxosceles, conocidas como «arañas violinistas», ingresa al organismo de una persona a través de su mordida. En México ocurre un subregistro de los casos de loxoscelismo por la ausencia de pruebas de laboratorio para su diagnóstico y la dificultad del cuadro clínico. El objetivo de este trabajo es describir un caso de loxoscelismo cutáneo ocasionado por mordedura de Loxosceles yucatana en un residente de Yucatán, México. El loxoscelismo cutáneo es el tipo más frecuente y menos severo. El presente caso se diagnosticó por medio de la sintomatología registrada en la historia clínica, la lesión inicial y la identificación de arañas L. yucatana. Este trabajo representa la primera descripción de un caso de loxoscelismo cutáneo con resolución favorable en Yucatán.

Loxoscelism occurs when the dermonecrotic venom produced by spiders of the genus Loxosceles, known as "violin spiders," enters a person's organism through their bite. In Mexico there is an underreporting of loxoscelism cases due to the absence of laboratory tests for its diagnosis and the complexity of the clinical picture. The aim of this paper is to describe a case of cutaneous loxoscelism caused by the bite of Loxosceles yucatana in a resident of Yucatan, Mexico. Cutaneous loxoscelism is the most frequent and less severe type. This case was diagnosed by means of the symptomatology registered in the medical records, the initial lesion, and the identification of L. yucatana spiders. This study represents the first description of a case of cutaneous loxoscelism with favorable outcome in Yucatan.

Temporal evolution of dermonecrosis in loxoscelism assessed by photodocumentation

ABSTRACT Background: Although loxoscelism (bites by brown spiders of the genus Loxosceles) frequently results in dermonecrosis, no previous clinical reports have provided detailed temporal photodocumentation of the evolution of dermonecrotic lesions in a case series. Methods This was a retrospective cohort study involving a case series of loxoscelism. Only cases of dermonecrosis with photodocumentation of lesion evolution (from admission until complete or almost complete healing) were included. Results: Eight patients (six men, two women; median age, 38 years) fulfilled the inclusion criteria. The bite sites included the thigh (n = 4), forearm (n = 2), abdomen (n = 1), and trunk (n = 1). Time interval between the bite and first contact with our service ranged from 15 to 216 h (median = 29 h). The main clinical manifestations included local erythematous and ischemic violaceous lesions overlying a base of indurated edema (livedoid plaque, 8), local pain (8), exanthema (6), serohemorrhagic vesicles/blisters (5), fever (5), and jaundice (1). Based on a previously established classification, the cases were classified as probable cutaneous-necrotic loxoscelism (CNL, n = 4), presumptive CNL (n = 3), and presumptive cutaneous-hemolytic loxoscelism (n = 1). Seven patients were treated with anti-arachnidic antivenom (AV; median time post-bite = 46 h). Complete lesion healing ranged from 34 to 98 days post-bite (median, 68 days; six patients). None of the patients required reconstructive plastic surgery. Conclusions The sequential photographic documentation showed considerable variation in the process of wound healing, with complete epithelialization requiring up to 3 months after the bite.

Loxoscelism in an HIV patient. The complexity behind a spider bite / Loxoscelismo en un paciente VIH. La complejidad detrás de la mordedura de una araña

Abstract Loxoscelism is a relatively common toxinological event in tropical countries. Although most are self-limiting, some cases may have serious local or systemic consequences. Unfortunately, lack of knowledge and limited diagnostic and treatment strategies still result in adverse outcomes in susceptible patients. The aim of this paper is to present a clinical case of serious loxoscelism in an HIV patient, highlighting the correlation between the clinical presentation and the toxinological characteristics of the poison. This was a previously healthy 48-year-old male patient with risky sexual habits, who experienced a serious arachnid accident after being bitten by a spider of the Loxosceles genus. He subsequently experienced a difficult clinical course, with deep vein thrombosis, progressively increasing transaminases to the range of hepatitis, and a de novo diagnosis of HIV, confirmed by fourth generation ELISA. This is the first case report of arachnidism in the context of HIV infection, which opens a discussion on the possible differential response of this population to the effects of spider poison. (Acta Med Colomb 2021; 46. DOI:https://doi.org/10.36104/amc.2021.2025).

Resumen El loxoscelismo es un evento toxinológico relativamente frecuente en los países tropicales. A pesar de que la mayoría son autolimitados, hay casos que pueden tener consecuencias locales o sistémicas graves. Lamentablemente el desconocimiento y la limitación en estrategias diagnósticas y terapéuticas aún representan desenlaces adversos en pacientes susceptibles. El objetivo de este trabajo es presentar un caso clínico de loxoscelismo grave en un paciente VIH, destacando la correlación entre la presentación clínica con las características toxinológicas del veneno. Se trató de un paciente masculino de 48 años previamente sano y con hábitos sexuales de riesgo, quien presentó accidente arácnido grave, posterior a mordedura por araña de género Loxosceles; con posterior evolución tórpida, desarrollo de trombosis venosa profunda, aumento progresivo de las transaminasas hasta el rango de hepatitis y diagnóstico de novo de VIH confirmado con Elisa de cuarta generación. Es el primer reporte de caso de aracnidismo en contexto de infección por VIH que lleva a discutir sobre una posible respuesta diferencial de esta población al efecto del veneno de araña. (Acta Med Colomb 2021; 46. DOI:https://doi.org/10.36104/amc.2021.2025).

Loxoscelismo cutáneo-visceral en una zona rural con desenlace favorable / Viscerocutaneous loxoscelism with a favorable outcome in a rural area

En el Perú los accidentes por mordedura de araña representan un problema de salud colectiva; de estos, el producido por la araña Loxosceles ha sido causa de numerosas muertes sobre todo en la costa. Esta tiende a ocasionar, ya sea una lesión cutánea o un cuadro sistémico, que puede llevar a la muerte del individuo si no es tratado a tiempo. Hasta la fecha no se cuenta con un protocolo de diagnóstico, predicción ni manejo a nivel internacional, por lo que se utilizan opciones terapéuticas sin respaldo de evidencia. Sin embargo, el manejo de soporte oportuno y adecuado es crucial para los cuadros severos. Se presenta el caso inusual de un loxoscelismo cutáneo-visceral o también llamado sistémico ocurrido en una zona rural. Hubo un compromiso renal severo que requirió hemodiálisis con un desenlace favorable a pesar del no uso de suero antiloxoscélico, lo que evidencia la importancia del manejo oportuno con las medidas de soporte adecuadas(AU)

Accidents caused by spider bites are a public health problem in Peru. Of these, those related to Loxosceles spider bites have been the cause of numerous deaths, mainly on the coast. These bites generally result in a cutaneous lesion or systemic involvement, which may threaten the person's life if not treated timely. An international protocol is not yet available for the diagnosis, prediction or management of Loxosceles spider bites. Therefore, therapeutic options are applied which are not supported by evidence. Still, timely and appropriate support management is crucial in severe cases. An unusual case of viscerocutaneous loxoscelism is presented, also known as systemic loxoscelism, which occurred in a rural area. The case was characterized by severe renal involvement requiring hemodialysis, but its outcome was favorable, despite not using antiloxoscelic serum, which shows the importance of timely management based on appropriate support measures(AU)

Síndrome compartimental agudo como complicación de un loxoscelismo cutáneo edematoso / Acute compartment syndrome as a complication of cutaneous loxoscelism mainly edematous

Resumen El síndrome compartimental agudo (SCA) es el aumento de la presión en un espacio osteofascial cerrado. Esto reduce la presión capilar bajo el nivel necesario para la viabilidad de los tejidos del compartimento. El SCA de mano como complicación de un loxoscelismo cutáneo (LC) de predominio edematoso es muy poco frecuente. Presentamos el caso de una mujer de 22 años que presentó un SCA de la mano secundario a un LC y que requirió tratamiento quirúrgico de urgencia mediante una fasciotomía dorsal y palmar.

Abstract Acute compartment syndrome (ACS) is the increase of pressure in a closed osteofascial space. This reduces capillary perfusion below the level necessary for tissue viability. Injury could be irreversible if proper treatment is not performed. Hand ACS secondary to cutaneous loxoscelism with edematous predominance is extremely infrequent. We present a clinical case of a 22-year-old patient who started a hand compartment syndrome secondary to cutaneous loxoscelism (CL), requiring emergency surgical treatment with dorsal and palmar fasciotomy.

Acute kidney injury due to systemic Loxoscelism: a cross-sectional study in Northeast Brazil

Abstract INTRODUCTION: Loxoscelism is a clinical condition involving spiders of the genus Loxosceles. One of the most severe complications is acute kidney injury (AKI). This study aimed to investigate AKI and other complications associated with loxoscelism. METHODS: We analyzed cases diagnosed with loxoscelism in an area where most accidents were caused by Loxosceles amazonica from January 2010 to December 2015. AKI was defined according to the KDIGO criteria. RESULTS: Forty-five patients were recorded: 95.6% presented characteristic necrotic skin lesions and 13.3% AKI. CONCLUSIONS: Loxoscelism could cause kidney involvement which is uncommon and could lead to the death of these patients.

Loxoscelismo escrotal / Scrotal loxoscelism

Loxoscelismo es el cuadro clínico originado por la mordedura de araña del género Loxosceles. Es considerado un accidente que ocurre con mayor frecuencia en las noches, debido al hábito nocturno de la araña y buena adaptación a los ambientes domésticos, preferentemente en espacios oscuros y secos. Clínicamente presenta dos escenarios, cutáneo (83,3 %) y visceral o sistémico (16 %), con una variación del cuadro cutáneo denominado loxoscelismo predominantemente edematoso. El objetivo es informar un caso inusual de loxoscelismo escrotal. El diagnóstico se realizó mediante las características clínicas y epidemiológicas del accidente. En conclusión, el loxoscelismo escrotal es una entidad muy infrecuente, el manejo del paciente influye mucho en su evolución y progresión; el tratamiento exhaustivo con sulfadiazina 2 veces al día y antibióticos intravenosos, muestra resultados muy favorables.

Loxoscelism is a condition produced by the bite of spiders from the genus Loxosceles. It is considered to be an accident that occurs mostly in the night, due to the spider's nocturnal habits and good adaptation to domestic environments, preferably dark, dry spaces. It presents in two clinical scenarios: cutaneous (83.3 %) and visceral or systemic (16 %), with a variation in the cutaneous manifestation known as predominantly edematous loxoscelism. The objective of the study was to report an unusual case of scrotal loxoscelism. Diagnosis was based on the clinical and epidemiological characteristics of the accident. It is concluded that scrotal loxoscelism is a very infrequent condition. Management of the patient greatly influences its evolution and progress. Exhaustive treatment with sulfadiazine twice daily and intravenous antibiotics yields very favorable results.

Loxoscelismo cutáneo: paciente con múltiples picaduras y con contraindicación para sulfas. Reporte de un caso / Cutaneous Loxoscelism: Patient with multiple bites and contraindication to sulfa drugs. Case report

RESUMEN Presentamos el caso clínico de un paciente adulto joven que consultó por picaduras de araña loxosceles y sus crías, con antecedentes personales importantes de trastorno de ansiedad generalizada y alergia tipo anafilaxia severa por sulfas y AINES. El proceso presentó evolución tórpida inicial con aparición de nuevas lesiones incluso 15 días después del accidente y a pesar de haber utilizado varias alternativas farmacológicas reportadas en la literatura como útiles (colchicina, antihistamínicos, esteroides, anticoagulantes, antibióticos) no había tenido respuesta, hasta la utilización de oxigeno por cámara hiperbárica con la cual frenó la aparición de nuevas lesiones y mejoró la reepitelialización sin necesidad de intervenciones quirúrgicas, con evolución exitosa.

SUMMARY We report the case of a young adult patient who presented bites by Loxosceles spider and its hatchlings with a history of importance of such allergy anaphylaxis severe by sulfa drugs and NSAIDs, generalized anxiety disorder, who presented initial torpid with new lesions even 15 days after the accident and despite having used several pharmacological alternatives reported in the literature as useful (colchicine , antihistamines, steroids, blood thinners, antibiotics) had not been answered, to the use of oxygen for hyperbaric chamber with which brake the appearance of new and improved reepithelialization injury without surgery, with successful evolution.

Experiencia en loxoscelismo cutáneo y cutáneo visceral de manejo hospitalario: clínica, evolución y propuesta terapéutica / Experience in visceral cutaneous and cutaneous loxoscelism of hospital management: clinical, evolution and therapeutic proposal

Resumen Introducción: El loxoscelismo es una patología frecuente en nuestro medio con un amplio espectro de presentaciones y diagnósticos diferenciales, con complicaciones potencialmente graves, e incluso con riesgo de muerte. A la fecha no existe un tratamiento estándar para estos pacientes. Objetivo: Describir las manifestaciones clínicas, principales complicaciones, manejo terapéutico y evolución de pacientes internados por loxoscelismo en un hospital terciario en Chile. Pacientes y Método: Se analizaron todos los pacientes consultantes e internados por loxoscelismo en el Hospital Clínico de la Pontificia Universidad Católica de Chile entre los años 2014 y 2017, evaluados en interconsulta por Dermatología. Revisión de los registros clínicos incluyendo semiología, imágenes, informes de laboratorio y tratamientos efectuados. Resultados: Se registraron 17 casos de loxoscelismo de manejo hospitalario, cuya presentación responde al patrón epidemiológico nacional. La mayoría de los casos fue manejada con antimicrobianos, corticosteroides sistémicos, antihistamínicos y dapsona. De ellos, 11,8% correspondieron a loxoscelismo cutáneo visceral, manejados exitosamente con medidas de soporte, corticosteroides sistémicos y antihistamínicos. El 59% presentó resolución de las lesiones al mes de tratamiento, con cicatriz residual leve o hiperpigmentación postinflamatoria, sin mortalidad en nuestra serie. Discusión: La mayoría de los casos de loxoscelismo cutáneo presentó excelente respuesta y rápida resolución del cuadro tras el tratamiento asociado de corticosteroides sistémicos, antimicrobianos y dapsona, sugiriendo que el uso de estas terapias podría detener la progresión de la necrosis cutánea y prevenir las complicaciones asociadas al loxoscelismo.

Background: Loxoscelism is a common pathology in our environment with a broad spectrum of differential diagnoses and presentations, with potentially serious complications, even to the point of death. To date, there is no standard treatment for these patients. Aim: To describe the clinical manifestations, main complications, therapeutic management, and evolution of loxoscelism in an inpatient setting from a tertiary hospital in Chile. Methods: All patients consulting and hospitalized in the hospital of the Pontificia Universidad Católica de Chile with diagnosis of loxoscelism between 2014 to 2017 and evaluated by dermatologist were included. Review of clinical files, including symptoms, images, laboratory parameters and treatment. Results: We evaluated seventeen inpatient with loxoscelism, whose presentation responds to the national epidemiological pattern. Most cases were managed with antibiotics, systemic corticosteroids, antihistamines, and dapsone. From these, 11.8% corresponded to viscerocutaneous loxoscelism, successfully managed with supportive measures, systemic corticosteroids and antihistamines. Fifty-nine percent healed their cutaneous lesions after one month of treatment, with slight residual scarring or post inflammatory hyperpigmentation, without associated mortality in our series. Discussion: Most cases of cutaneous loxoscelism presented excellent response and rapid resolution of the disease after combined therapy with systemic corticosteroids, antibiotics and dapsone, suggesting that the use of these therapies could stop the progression of cutaneous necrosis and prevent complications associated with loxoscelism.

Presentación de un protocolo efectivo para el tratamiento de la miodermonecrólisis por loxoscelismo cutáneo / Presentation of an eff ective protocol for the treatment of miodermonecrolisis by cutaneous loxoscelism

Las lesiones por mordedura de arácnidos del género Loxosceles producen lesiones locales y presentan pérdida de tejidos, con necrosis extensas que requieren cirugía reparadora. En algunos casos se observan lesiones sistémicas graves como hemólisis, coagulación intravascular diseminada e insufi ciencia renal aguda, que pueden desencadenar coma y muerte. Se aplicó un protocolo sistematizado basado en fasciotomías descompresivas, necrosectomías y posteriores coberturas con colgajos e injertos a pacientes que ingresaron con lesiones de aspecto necróticas con antecedente de contacto con arácnidos del género Loxosceles y clínica de miodermonecrólisis. Los casos tratados, evolucionaron favorablemente, con secuelas variables y sin comorbilidades importantes. Se presenta un modelo de protocolo actualizado, que permite efectivizar el tratamiento

The lesions for the arachnid's bite of the genus Loxosceles produce local lesions and present tissue loss whit extensive necrosis and required restorative surgery. In some cases, presents severe systemic lesions such as hemolysis, disseminated intravascular coagulation and acute renal failure can develop coma and death. Patients admitted with necrotic lesions with antecedent of contact with arachnids of the genus Loxosceles and clinic of miodermoncrelisis. A systematized protocol was applied based on decompressive fasciotomies, necrosectomies and posterior fl ap and graft coverage. The treated cases evolved favorably, without major comorbidities. An updated protocol model is presented, which allows eff ective treatment

Long time not seen: Expanding the records of Loxosceles amazonica (Araneae: Sicariidae) in the Amazonas state, Brazil / Muito tempo sem ver: Expansão dos registros de Loxosceles amazonica (Araneae: Sicariidae) para o estado do Amazonas, Brasil

Spiders of the genus Loxosceles, commonly known as brown recluse spiders, can cause serious accidents in humans. Their venom has a powerful proteolytic and hemolytic action. Each year these spiders are the cause of a great number of araneism in Brazil. This work presents new records of Loxosceles amazonica for the municipal districts of Manaus and Iranduba, Amazonas, Brazil.

As aranhas do gênero Loxosceles, conhecidas como aranhas marrons, podem causar sérios acidentes em humanos. O veneno destas aranhas possui potente ação proteolítica e hemolítica. A cada ano estas aranhas são responsáveis pelo maior número de araneísmos no Brasil. Este trabalho apresenta novos registros de Loxosceles amazonica para o estado do Amazonas, Brasil.

Evolución clínica de pacientes con loxoscelismo sistémico y dermonecrótico en un hospital de tercer nivel / Clinical evolution of patients with systemic and dermonecrotic loxoscelism in a third level hospital

Resumen ANTECEDENTES: el loxoscelismo es una intoxicación por la mordedura de la araña Loxosceles reclusa, cuyo veneno contiene esfingomielinasa-D, causante de hemólisis y necrosis. Se reporta una serie de casos que describen su evolución clínica y respuesta al tratamiento. OBJETIVO: describir la evolución y características clínicas de pacientes con loxoscelismo sistémico y dermonecrótico, su respuesta al tratamiento y las complicaciones. PACIENTES Y MÉTODO: estudio que incluyó el análisis descriptivo de pacientes tratados en el servicio de Medicina Interna, Unidad Médica de Alta Especialidad Dr. Antonio Fraga Mouret, Centro Médico Nacional La Raza, de 2010 a 2015. RESULTADOS: se atendieron ocho hombres (67%) y cuatro mujeres (33%), con edad media de 39.4 años (16-83 años). El sitio de mordedura en cinco casos (42%) fue el miembro pélvico izquierdo; cuatro casos en el miembro torácico derecho (33%), dos en la cara (17%) y uno en el miembro torácico izquierdo (9%). Nueve casos provenían del Estado de México, dos de la Ciudad de México y uno de Hidalgo. Manifestación clínica: flictenas (cinco casos), edema y eritema (tres), placa liveloide (tres) y necrosis (un caso). Nueve (75%) pacientes se trataron inicialmente en la unidad de cuidados intensivos. Se reportaron las siguientes complicaciones sistémicas: renales (67%), pulmonares con administración de aminas (33%) y hematológicas (8%). Diez casos recibieron faboterápico, con media de 1.5 viales (0 a 4); cinco casos (42%) recibieron dapsona y cuatro de ellos (33%) padecieron metahemoglobinemia; once (92%) pacientes requirieron lavado-desbridación y 7 (58%) injerto cutáneo; cuatro pacientes (33%) tuvieron infección agregada de la herida. El promedio de estancia hospitalaria fue 16.2 días (3 a 40 días). CONCLUSIÓN: la evolución y pronóstico de esta afección depende de una sospecha inicial, diagnóstico y tratamiento oportunos. El loxoscelismo debe incluirse en los diagnósticos diferenciales de lesiones necróticas y progresivas, con o sin afección sistémica.

Abstract BACKGROUND: Loxoscelism is a poisoning caused by the bite of Loxosceles recluse spider, whose venom contains sphingomyelinaseD, causing hemolysis and necrosis. We report a case series describing their clinical course and response to treatment. OBJECTIVE: To describe the evolution and clinical characteristics of patients with systemic and dermonecrotic loxoscelism, their response to treatment and complications. PATIENTS AND METHOD: A descriptive analysis of patients treated in the Internal Medicine Service, Centro Médico Nacional La Raza, from 2010 to 2015. RESULTS: A total of 8 men (67%) and 4 women (33%) were included. Mean age was 39.4 years (16-83 years). Bite site was left pelvic limb in 5 cases (42%), 4 in the right forelimb (33%), 2 in the face (17%) and 1 in left forelimb (9%). Nine cases came from Estado de México, 2 from Mexico City and 1 from Hidalgo. Initial manifestations included blisters (five cases), edema and erythema (three cases), liveloide plate (three cases) and necrosis (one case). Nine (75%) patients were initially managed in ICU. Systemic complications were renal (67%), lung with use of amines (33%) and hematological (8%). Ten cases were treated with fabotherapy, with an average of 1.5 vials (0-4). Five cases (42%) received dapsone and 4 of them (33%) developed methemoglobinemia. Eleven (92%) required surgical washing and debridement and 7 (58%) skin graft; four patients (33%) had secondary wound infection. Average hospital stay was 16.2 days (3-40 days). CONCLUSIONS: The evolution and prognosis depends on initial suspicion early diagnosis and treatment. Loxoscelism should be included in the differential diagnosis of progressive necrotic lesions, with or without systemic involvement.

Highlights in the knowledge of brown spider toxins

Abstract Brown spiders are venomous arthropods that use their venom for predation and defense. In humans, bites of these animals provoke injuries including dermonecrosis with gravitational spread of lesions, hematological abnormalities and impaired renal function. The signs and symptoms observed following a brown spider bite are called loxoscelism. Brown spider venom is a complex mixture of toxins enriched in low molecular mass proteins (4-40 kDa). Characterization of the venom confirmed the presence of three highly expressed protein classes: phospholipases D, metalloproteases (astacins) and insecticidal peptides (knottins). Recently, toxins with low levels of expression have also been found in Loxosceles venom, such as serine proteases, protease inhibitors (serpins), hyaluronidases, allergen-like toxins and histamine-releasing factors. The toxin belonging to the phospholipase-D family (also known as the dermonecrotic toxin) is the most studied class of brown spider toxins. This class of toxins single-handedly can induce inflammatory response, dermonecrosis, hemolysis, thrombocytopenia and renal failure. The functional role of the hyaluronidase toxin as a spreading factor in loxoscelism has also been demonstrated. However, the biological characterization of other toxins remains unclear and the mechanism by which Loxosceles toxins exert their noxious effects is yet to be fully elucidated. The aim of this review is to provide an insight into brown spider venom toxins and toxicology, including a description of historical data already available in the literature. In this review article, the identification processes of novel Loxosceles toxins by molecular biology and proteomic approaches, their biological characterization and structural description based on x-ray crystallography and putative biotechnological uses are described along with the future perspectives in this field.(AU)

Highlights in the knowledge of brown spider toxins

Abstract Brown spiders are venomous arthropods that use their venom for predation and defense. In humans, bites of these animals provoke injuries including dermonecrosis with gravitational spread of lesions, hematological abnormalities and impaired renal function. The signs and symptoms observed following a brown spider bite are called loxoscelism. Brown spider venom is a complex mixture of toxins enriched in low molecular mass proteins (440 kDa). Characterization of the venom confirmed the presence of three highly expressed protein classes: phospholipases D, metalloproteases (astacins) and insecticidal peptides (knottins). Recently, toxins with low levels of expression have also been found in Loxosceles venom, such as serine proteases, protease inhibitors (serpins), hyaluronidases, allergen-like toxins and histamine-releasing factors. The toxin belonging to the phospholipase-D family (also known as the dermonecrotic toxin) is the most studied class of brown spider toxins. This class of toxins single-handedly can induce inflammatory response, dermonecrosis, hemolysis, thrombocytopenia and renal failure. The functional role of the hyaluronidase toxin as a spreading factor in loxoscelism has also been demonstrated. However, the biological characterization of other toxins remains unclear and the mechanism by which Loxosceles toxins exert their noxious effects is yet to be fully elucidated. The aim of this review is to provide an insight into brown spider venom toxins and toxicology, including a description of historical data already available in the literature. In this review article, the identification processes of novel Loxosceles toxins by molecular biology and proteomic approaches, their biological characterization and structural description based on x-ray crystallography and putative biotechnological uses are described along with the future perspectives in this field.

Loxoscelismo cutáneo predominantemente edematoso: a propósito de un caso / Cutaneous loxoscelism mainly edematous: a case report

In Chile, loxoscelism is caused by the bite of the Loxosceles laeta spider. The clinical presentation has two different forms: cutaneous loxoscelism (CL) and vicero-cutaneous loxoscelism, which is less frequent. Cutaneous loxoscelism includes an uncommon clinical variation (4%), called CL with edematous predominance (CLEP). We present a 5-year-old patient with sudden pain and edema on his right eyelid associated with fever, which progressed rapidly involving the right hemifacial area, frontal region, and left eyelid. Angioedema and pre-orbital cellulitis were discarded and CLEP was suspect. Cutaneous loxoscelism with an edematous predominance is self-limited, benign and with little or no necrotic injury due to the edema, which dilutes the toxin-induced enzymatic process causing necrosis. As in the reported cases it usually responds well to medical treatment and does not cause visceral involvement.

El loxoscelismo en Chile es un cuadro producido por la mordedura de la araña Loxosceles laeta. Las formas de presentación son: loxoscelismo cutáneo (LC) y loxoscelismo cutáneo-visceral (LCV), el último menos frecuente. Dentro del LC existe una variante poco común (4%) conocida como loxoscelismo cutáneo predominantemente edematoso (LCPE). Nuestro caso es un paciente de 5 años que consultó por cuadro de inicio súbito de dolor y edema palpebral derecho, asociado a fiebre el cual evolucionó con rápida progresión extendiéndose en la hemicara derecha, región frontal y párpado izquierdo. Se descartó un angioedema y una celulitis periorbitaria, sospechándose un LCPE. Se manejó con hidrocortisona y clorfenamina. El LCPE es un cuadro benigno, autolimitado, en que no está presente la lesión necrótica o ésta es insignificante. Predomina el edema, el cual abortaría la necrosis al diluir el proceso enzimático producido por el veneno. Tiene buena respuesta al tratamiento médico, con ausencia de compromiso visceral.

Acidente loxoscélico / Loxoscelic accident

Os acidentes com aranhas do gênero Loxosceles podem apresentar variadas evoluções clínicas, dificultando a realização do diagnóstico e a escolha correta de uma medida terapêutica. Este artigo de revisão tem como objetivo abordar os mais importantes mecanismos de evolução, principais desfechos e os tratamentos de escolha para o acidente loxoscélico (AU)

Accidents with Loxosceles genus spiders may have different clinical outcomes, hindering the diagnosis and the correct choice of a therapeutic measure. This review article aims to address the main mechanisms of evolution, main outcomes and treatments of choice for loxoscelic accident (AU)