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Background: Breast reconstruction following mastectomy is a critical component of breast cancer treatment, aimed at improving patient quality of life. However, the management is fraught with potential complications, including skin necrosis and wound dehiscence, which can significantly impact clinical outcomes. Case Presentation: We report a unique case of a patient, 5 years post-breast reconstruction following mastectomy and radiation therapy, who developed severe skin necrosis and wound dehiscence due to a brown recluse spider bite on the reconstructed breast. The complication necessitated the debridement of skin, removal of the implant, and further reconstruction with a latissimus flap. Discussion: The case underscores the unusual etiology of spider bite-induced necrosis in breast reconstruction and highlights the challenges and strategic considerations in managing such complications. Upon presentation, the patient's affected breast area showed signs of extensive necrosis and wound dehiscence, directly attributed to the cytotoxic effects of the brown recluse spider's venom. The venom's pathophysiology involves a complex cascade, leading to local and systemic effects. The local effects, marked by dermonecrosis, com- promised skin integrity in this instance. Systemic effects, not observed in this patient but potentially severe, can include hemolysis, coagulopathy, and acute renal failure, highlighting the seriousness of brown recluse spider bites. Conclusion: In conclusion, this case illustrates the complexities of managing breast reconstruction post-mastectomy complications, particularly those caused by external factors such as brown recluse spider bites. It highlights the need for meticulous attention to unusual etiologies of necrosis and dehiscence, demonstrating the importance of adaptable surgical strategies and a thorough understanding of venom pathophysiology in ensuring successful patient outcomes.

The aim of this case report is to highlight an uncommon diagnosis for necrotic wounds. Brown recluse spider bites are a challenging clinical diagnosis and need to be considered as part of differential diagnoses, especially with the spider's natural distribution altering due to the effects of climate change. We present a case of a 44-year-old female patient who developed systemic symptoms and wound necrosis from a presumed brown recluse spider bite. The patient had multiple risk factors for poor wound healing and necrotic skin infections. It is important to be able to recognise unique manifestations of this rare diagnosis in order to avoid delay of timely and effective intervention and treatment. Declaration of interest: The authors have no conflicts of interest. [ABSTRACT FROM AUTHOR]

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Spiders are eight-legged arthropods that belong tothe arachnids class and are found on every continentexcept Antarctica.1 As of 2020, there are over 48000recognized species of spiders with more than 5000in the Mediterranean area. Out of these, only twospiders, the Latrodectus tredecimguttatus and theLoxosceles rufescens are of medical significance in theMediterranean area.1 Although most spider bites arebenign; however, severe reactions and life-threateningenvenomation do occur.

Key Clinical Message: Clinicians should be aware of the occurrence of deep vein thrombosis following brown recluse spider bite. [ABSTRACT FROM AUTHOR]

Key Clinical Message Clinicians should be aware of the occurrence of deep vein thrombosis following brown recluse spider bite.

A brown recluse spider (BRS) bite is challenging to confirm, but can be clinically diagnosed by considering the location, the season of the year and the clinical manifestations. We described a 26-year-old male who presented after a BRS bite with a skin lesion, bruising, severe swelling and diffuse blisters on the right lower extremity after 3 days. This case should be considered in the differential diagnosis of necrotizing fasciitis. Although spider bite poisoning is rare, proper diagnosis and management are important because, in some cases, it can have devastating outcomes. [ABSTRACT FROM AUTHOR]

Spiders of Loxosceles genus, or Brown spiders produce a potent venom with minimal volume and protein content. Among its toxins, phospholipases D (PLDs) are notable for causing primary local and systemic manifestations observed following envenomation. They degrade cellular phospholipids, mainly sphingomyelin and lysophosphatidylcholine. We present a robust and detailed analysis of PLD transcripts from venom glands of three major clinically relevant South American species-L. intermedia, L. laeta, and L. gaucho-using next-generation sequencing. Results confirmed that PLDs are the most highly expressed toxins, accounting for 65.4 % of expression in L. intermedia, 71.8 % in L. gaucho, and 50.4 % in L. laeta. These findings further support the idea that these enzymes form a protein family both within and across species. Eighteen contigs for PLDs were found for L. gaucho, 24 for L. intermedia, and 21 for L. laeta. A detailed analysis revealed that, although all contigs display conserved amino acid residues directly involved in catalysis, magnesium coordination, and substrate affinity, they also possess distinct primary sequences with important substitutions. Such data reinforces the hypothesis that these toxins may act synergistically. Furthermore, new PLD sequences were identified within the contigs. For L. intermedia, 14 potential new isoforms were identified; 16 for L gaucho; and 16 novel sequences for L. laeta. This indicates that there is still a wealth of undisclosed information about these toxins. These data will help identify structural and functional differences among these proteins, support future functional studies, and to the comprehensive understanding of the mechanism of action of PLDs., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Silvio Sanches Veiga reports financial support was provided by National Council for Scientific and Technological Development- Brazil. Silvio Sanches Veiga reports financial support was provided by Araucaria Foundation. Luiza Helena Gremski reports financial support was provided by National Council for Scientific and Technological Development - Brazil. Silvio Sanches Veiga reports a relationship with National Council for Scientific and Technological Development - Brazil that includes: funding grants. Silvio Sanches Veiga reports a relationship with Araucaria Foundation that includes: funding grants. Luiza Helena Gremski reports a relationship with National Council for Scientific and Technological Research that includes: funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Brown recluse spider bites can lead to severe reactions such as skin necrosis,hemolytic anemia, and multiorgan failure, which can be life-threatening. Therapeutic plasma exchange has been reported to provide clinical benefit for such cases. In thisreport, we present a case of a brown recluse spider bite that was successfully treated with therapeutic plasma exchange and compare it with previous case reports. [ABSTRACT FROM AUTHOR]

Objectives: To develop a sensitive and specific protocol for detecting preclinical hemolysis in patients with brown recluse spider (BRS) bites by comparing a large cohort of individuals with brown recluse spider (BRS) bites with and without hemolytic anemia.Methods: A cross-sectional, retrospective analysis of clinical features and laboratory values, including urinalysis (UA) and peripheral blood results, and timing of positive laboratory values prior to a significant drop in hematocrit was performed to evaluate effective predictors of clinically significant hemolysis.Results: In total, 275 patients with BRS bites were identified (64 with hemolytic anemia). Sensitivity and specificity of UA positive for blood (with and without microscopic hematuria) for detecting hemolysis were 72% and 75%, respectively. The combination of elevated serum total bilirubin (TB) and lactate dehydrogenase (LDH) had greater sensitivity (94%) and specificity (91%) for detecting patients developing hemolysis. When TB and LDH were evaluated prior to a significant decrease in hematocrit, they were positive in 82% of cases, while UA was positive for blood prior to a hematocrit decrease in 38% of cases.Conclusions: Serum TB and LDH levels are more effective at detecting preclinical hemolysis than UA and should be serially analyzed to triage patients with BRS bites before life-threatening hemolysis occurs. [ABSTRACT FROM AUTHOR]

We report an interesting clinical case of Acquired Haemophilia A (AHA) after a probable Loxosceles rufescens spider bite in a 73-year-old woman, admitted to an Emergency Department (ED) of Central Italy during April 2019. AHA is a rare disease, whose acute clinical manifestations are not widely known by most ED physicians; its prompt recognition and treatment are crucial to avoid fatal bleeding. In particular, the development of AHA after a violin spider bite (another rare and poorly characterized clinical condition) has never been described. Therefore, our case report could provide useful insight into the understanding and treatment of such unusual and possibly life-threatening conditions. [ABSTRACT FROM AUTHOR]

Background/Aim: Brown recluse spider bite releases hemolytic and cytotoxic phospholipase D to the wound that may cause necrosis or even death. We examined diethyl azelate (DEA), a plasma membrane fluidizer with a broad range of immunomodulatory activities, as a potential treatment for the brown recluse spider bite. Materials and Methods: Topical DEA was used in emergency to treat brown recluse spider bites in a human subject. We subsequently evaluated the effects of DEA on hemolysis induced by the brown recluse spider venom, recluse recombinant phospholipase D (rPLD), and venoms from honey bee and moccasin snake, and on phospholipase A2 activity in the bee and snake venoms and in human urine. Results: Topical DEA resolved the consequences of human brown recluse spider envenomation in two weeks. In vitro, DEA inhibited hemolysis caused by the brown recluse spider venom and rPLD and suppressed phospholipase A2 activity in a dosedependent manner. Conclusion: DEA is a promising novel therapy for the brown recluse spider bite and perhaps even unrelated envenomations involving PLDs. [ABSTRACT FROM AUTHOR]

Introduction: Systemic loxoscelism is the most severe complication of loxoscelism. The management of the cadre by health personnel presents a high variability due to factors that are currently unknown. There is no standard of reference or a clinical prediction model that can guide our decisions when approaching a spider bite patient. Objective: Develop and validate a clinical prediction rule for systemic loxoscelism. Methods: An observational study of derivation and validation of a clinical prediction model was carried out with diagnostic test validation based on a historical single-arm cohort in patients treated at Vitarte Hospital between 2007 and 2016 and international clinical reports published. Results: Systemic loxoscelism occurred only in 32.9% (n = 24) of cases. For the bivariate analysis, the variables that showed a statistically significant association (P

This case report has the main objective of providing education surrounding the presentation, evaluation, diagnosis, and treatment of Loxosceles reclusa envenomation and presenting a case of loxoscelism that occurred in an adult that subsequently presented to the emergency department. A secondary objective of this case report is to add to the literature of images bite wound images associated with loxoscelism that resulted in inpatient admission and treatment for acute hemolytic anemia., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Laxton et al.)

The brown recluse spider ( Loxosceles reclusa ) is endemic to the southcentral Midwest and the Southern United States. A bite from a brown recluse spider may result in symptoms that range from local skin necrosis to systemic complications such as acute haemolytic anaemia, disseminated intravascular coagulopathy, rhabdomyolysis and death. Although rare, systemic loxoscelism is a clinical diagnosis of exclusion that should be considered in a patient with acute autoimmune haemolytic anaemia. We describe a case of a young man with autoimmune haemolytic anaemia secondary to systemic loxoscelism successfully treated with intravenous immunoglobulin and steroids., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

In recent years, several endemic species of Loxosceles , violin spiders, have been described from the North-Central Chile biodiversity hotspot, some of which have ambiguous placement within the species groups of the genus. In a recent expedition to the Atacama region, we collected male specimens representing new records of two recently described species: Loxoscelesvicentei Taucare-Ríos, Brescovit & Villablanca, 2022 and Loxoscelesvallenar Brescovit, Taucare-Ríos, Magalhaes & Santos, 2017 (Araneae, Sicariidae). Males of the latter are hitherto unknown and are here described for the first time. Examination of the morphology of these species revealed characters such as an embolic keel and digitiform median receptacles, which suggest they do not belong in the laeta species group, but rather in the spadicea species group, which is briefly re-diagnosed. With carapace lengths smaller than 2 mm, the newly discovered males of L.vallenar are the tiniest members of the genus. In addition, males of this species bear strong macrosetae in the clypeus, a sexually dimorphic character not previously reported in Loxosceles ., Competing Interests: The authors have declared that no competing interests exist., (Ivan L. F. Magalhaes, Hernán A. Iuri, Antonio D. Brescovit, Jaime Pizarro-Araya.)

The Loxosceles genus represents one of the main arachnid genera of medical importance in Brazil. Despite the gravity of Loxosceles-related accidents, just a handful of species are deemed medically important and only a few have undergone comprehensive venom characterization. Loxosceles amazonica is a notable example of a potentially dangerous yet understudied Loxosceles species. While there have been limited reports of accidents involving L. amazonica to date, accidents related to Loxosceles are increasing in the North and Northeast regions of Brazil, where L. amazonica has been reported. In this work, we provide a complementary biochemical and immunological characterization of L. amazonica venom, considering its most relevant enzymatic activities and its immunorecognition and neutralization by current therapeutic antivenoms. Additionally, a cDNA library enriched with phospholipase D (PLD) sequences from L. amazonica venom glands was built and subsequently sequenced. The results showed that L. amazonica venom is well immunorecognised by all the tested antibodies. Its venom also displayed proteolytic, hyaluronidase, and sphingomyelinase activities. These activities were at least partially inhibited by available antivenoms. With cDNA sequencing of PLDs, seven new putative isoforms were identified in the venom of L. amazonica. These results contribute to a better knowledge of the venom content and activities of a synanthropic, yet understudied, Loxosceles species. In vivo assays are essential to confirm the medical relevance of L. amazonica, as well as to assess its true toxic potential and elucidate its related pathophysiology., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.)

Loxosceles rufescens is a spider that may bite humans. To describe the clinical manifestations and treatment of patients with bites caused by L. rufescens, and present scanning electron microscopy of the spider. Twelve patients are described, seven with a confirmed aetiological diagnosis as a sample of the spider was captured. In one case, scanning electron microscopy of the spider was performed. Seven patients presented with a single necrotic ulcer of varying morphology, with a purulent-necrotic bed, located on the neck (one patient), buttock (one patient), thigh (one patient), legs (three patients) and foot (one patient). All patients complained of burning and pain. No systemic symptoms were observed. All patients were treated with sodium hypochlorite solution packs, an equine catalase gel, and polyhexamethylene biguanide cream. Oral analgesics were added. In one patient, oral prednisone was prescribed. Two patients with bacterial superinfections were treated with i.v. piperacillin/tazobactam or i.m. ceftriaxone. All patients recovered within eight weeks, however, a scar developed in five of six patients. The sequence of cutaneous manifestations due to L. rufescens bites is typical. At first, erythema and oedema forms, followed by a vesicle, blister or pustule and, finally, an eschar and scar. Systemic symptoms and signs are rare. To consider this spider as an aetiological agent of necrotic ulcers, it is necessary to capture a sample of the spider, dead or alive, which should then be identified by an expert. Corticosteroids, antibiotics and analgesics are frequently used. Surgery is often necessary.

Background: Envenomation from the brown recluse spider (Loxosceles reclusa) is described to cause both local and systemic symptoms. We report a case of an adolescent boy who developed severe systemic loxoscelism, and his clinical course was complicated by myocarditis, which has not been previously reported in association with loxoscelism. Case Report: A 16-year-old boy presented with non-specific symptoms and forearm pain following a suspected spider bite, which subsequently evolved into a necrotic skin lesion. During his clinical course, he developed a characteristic syndrome of systemic loxoscelism with hemolysis, disseminated intravascular coagulopathy, and severe systemic inflammatory response syndrome, necessitating transfer to the Intensive Care Unit. The diagnosis was confirmed with an enzyme-linked immunosorbent assay that detected Loxosceles venom in the wound. Additionally, he developed pulmonary edema and cardiogenic shock secondary to myocarditis, which was confirmed with cardiac magnetic resonance imaging. Steroids and plasmapheresis were initiated to manage the severe inflammatory syndrome, and the myocarditis was treated with intravenous immunoglobulins, resulting in resolution of symptoms and improvement of cardiac function. Conclusions: This is the first reported case of myocarditis associated with loxoscelism, providing evidence for Loxosceles toxin-associated cardiac injury, which has been previously described in animal models only. Furthermore, this case provides further support for the use of confirmatory testing in the clinical diagnosis of loxoscelism. [ABSTRACT FROM AUTHOR]

Brown recluse spiders, also known as Loxosceles reclusa, are endemic to the Southwest and Central Midwestern United States. A bite from this spider can cause a range of clinical manifestations, anywhere from a painless papular lesion to life-threatening reactions. We report a possible spider bite presenting as leukostasis initially suspected to be acute leukemia. A 22-year-old female patient presented to the emergency department with confusion and right upper arm pain, redness, and swelling after a suspected spider bite. Initial labs showed WBC count of 103.5x10e3/µL, hemoglobin of 3.3 g/dL, positive Direct Coombs' test, creatinine of 1.8 mg/dL, transaminitis, and lactic acid of 20 mmol/L. Acute leukemia with leukostasis was suspected. She was started emergently on hydroxyurea in conjunction with prophylaxis for tumor lysis syndrome. However, peripheral smear showed left-shifted granulocytosis with lymphocytosis, monocytosis, and no blast cells or evidence of myelodysplasia. Bone marrow aspirate showed mildly hypercellular marrow with myeloid hyperplasia and no myelodysplasia. Flow cytometry analysis confirmed a left-shifted myeloid maturation pattern with 0.3% myeloblasts. BCR-ABL1 and JAK2 testing was negative. Hence, she had no evidence of leukemia but rather had leukostasis from a spider bite. Hydroxyurea was stopped and follow-up labs normalized. Sphingomyelinase D in the brown recluse spider venom is unique to Loxosceles and Sicarius and may be responsible for the unique clinical presentation of loxoscelism. The presentation of hyperleukocytosis complicated by shock with an unclear history poses a diagnostic challenge. In diagnostic uncertainty, consider delaying chemotherapy until a diagnosis can be confirmed to avoid potential harm. [ABSTRACT FROM AUTHOR]

Background: Breast reconstruction following mastectomy is a critical component of breast cancer treatment, aimed at improving patient quality of life. However, the management is fraught with potential complications, including skin necrosis and wound dehiscence, which can significantly impact clinical outcomes., Case Presentation: We report a unique case of a patient, 5 years post-breast reconstruction following mastectomy and radiation therapy, who developed severe skin necrosis and wound dehiscence due to a brown recluse spider bite on the reconstructed breast. The complication necessitated the debridement of skin, removal of the implant, and further reconstruction with a latissimus flap., Discussion: The case underscores the unusual etiology of spider bite-induced necrosis in breast reconstruction and highlights the challenges and strategic considerations in managing such complications. Upon presentation, the patient's affected breast area showed signs of extensive necrosis and wound dehiscence, directly attributed to the cytotoxic effects of the brown recluse spider's venom. The venom's pathophysiology involves a complex cascade, leading to local and systemic effects. The local effects, marked by dermonecrosis, com- promised skin integrity in this instance. Systemic effects, not observed in this patient but potentially severe, can include hemolysis, coagulopathy, and acute renal failure, highlighting the seriousness of brown recluse spider bites., Conclusion: In conclusion, this case illustrates the complexities of managing breast reconstruction post-mastectomy complications, particularly those caused by external factors such as brown recluse spider bites. It highlights the need for meticulous attention to unusual etiologies of necrosis and dehiscence, demonstrating the importance of adaptable surgical strategies and a thorough understanding of venom pathophysiology in ensuring successful patient outcomes., Competing Interests: None., (© 2024 The Authors.)

Broadly-neutralizing monoclonal antibodies are becoming increasingly important tools for treating infectious diseases and animal envenomings. However, designing and developing broadly-neutralizing antibodies can be cumbersome using traditional low-throughput iterative protein engineering methods. Here, we present a new high-throughput approach for the standardized discovery of broadly-neutralizing monoclonal antibodies relying on phage display technology and consensus antigens representing average sequences of related proteins. We showcase the utility of this approach by applying it to toxic sphingomyelinases from the venoms of species from very distant orders of the animal kingdom, the recluse spider and Gadim scorpion. First, we designed a consensus sphingomyelinase and performed three rounds of phage display selection, followed by DELFIA-based screening and ranking, and benchmarked this to a similar campaign involving cross-panning against recombinant versions of the native toxins. Second, we identified two scFvs that not only bind the consensus toxins, but which can also neutralize sphingomyelinase activity of native whole venom in vitro. Finally, we conclude that the phage display campaign involving the use of the consensus toxin was more successful in yielding cross-neutralizing scFvs than the phage display campaign involving cross-panning., (© 2024 The Authors. Protein Science published by Wiley Periodicals LLC on behalf of The Protein Society.)

Background: Brown recluse spider (BRS) (Loxosceles reclusa) envenomation can cause local dermonecrotic lesions, constitutional symptoms, and potentially fatal hemolysis (i.e., cutaneous-hemolytic loxoscelism). As the incidence of hemolysis is low and the spider habitat is limited, little is known regarding the clinical course of cutaneous-hemolytic loxoscelism. Methods: We performed a retrospective observational study of patients following BRS envenomation over an eight-year period. Demographics, clinical course, laboratories, and interventions were assessed. Wilcoxon rank-sum tests and Pearson chi-square tests were used in the univariate analyses. Logistic regression assessed the independent contribution of symptoms in a multivariate analysis. Results: Of the 97 patients, 40.2% (n = 39) developed hemolysis; the majority (66.7%) were 18 years old or younger. Univariate analysis revealed that constitutional symptoms were associated with hemolysis, but multivariate analysis showed only myalgia (aOR: 7.1; 95% CI: 2.2–22.7; p <.001) and malaise (aOR: 12.76; 95% CI: 1.4–119.9; p =.026) were independently associated with hemolysis. The median time to hemolysis onset was 1.0 days (IQR: 1.0–2.5) and all occurred within a week of envenomation. Hemolysis durations were longer in patients DAT positive for IGG antibodies (7.5 vs. 4.0 days; p =.042). Most (76.9%) of hemolyzing patients received blood. In patients with cutaneous-hemolytic loxoscelism, hematuria occurred in 32.4%, rhabdomyolysis occurred in 60.9%, and elevated transaminases with normal hepatic synthetic function occurred in 29.4% but all of these patients developed rhabdomyolysis. Hemolysis was both intravascular and extravascular. Complications (hyperkalemia, INR ≥2.0, metabolic acidosis requiring bicarbonate, hypotension requiring vasopressors, and hypoxia requiring intubation) occurred only in patients with profound hemolytic anemia (hemoglobin <4 g/dL); one patient died. Conclusions: Constitutional symptoms occur in both cutaneous and cutaneous-hemolytic loxoscelism, although they occur more frequently in patients who develop hemolysis. Children may be at a higher risk of hemolysis after envenomation. Renal involvement (as evidenced by hematuria) and rhabdomyolysis may occur more frequently than has been previously reported. Hemolysis was both intravascular and extravascular. [ABSTRACT FROM AUTHOR]

We present the first record for Loxosceles gaucho Gertsch, 1967 in the Amazonian region of Brazil. Four males, fifteen females and forty-nine immatures were collected in different places in Manaus, Amazonas, Brazil. This is the third species of Loxosceles reported in the Amazon region along with L. amazonica Gertsch, 1967, and L. similis Moenkhaus, 1898. This is the first record of an invasive species of a venomous animal in the state of Amazonas, Brazil, which is noteworthy due to its synanthropic habit, which increases the risk to the local population. [ABSTRACT FROM AUTHOR]

We conducted a two-year mark-recapture study of a synanthropic population of the brown recluse spider Loxosceles reclusa Gertsch & Mulaik, 1940 in northwestern Illinois. We used joint live encounter and dead recovery models to estimate adult survival, recapture, and dead recovery probabilities. To estimate adult abundance, we used fulllikelihood closed-population models. Monthly survival was constant between sexes (0.73, 95% CI ¼ 0.66-0.78), but males were less likely to be recaptured and an additive effect of time revealed highest recapture probabilities in September. The probability of recovering a marked adult that died during the study was 0.13 (95% CI¼0.07-0.24). Average life expectancy for adults was 94 days, much lower than in prior laboratory studies. Causes of observed mortality were predation by conspecifics and cobweb spiders (Parasteatoda tepidariorum (C.L. Koch, 1841)) or undetermined. A likely source of mortality for this sit-and-wait predator is starvation. Model averaging of full likelihood closed-population models resulted in adult abundance estimates that were similar between males (28, 95% CI ¼ 20-63) and females (28, 95% CI ¼ 26-38). However, the total population of adults including those hidden in harborage (boxes, furniture, crevices etc.) was undoubtedly much higher. Based on count data, immature spiders were as abundant as adults early in the year, gradually increasing to a peak three times greater by mid-summer. Male spiders moved longer distances than females and were less likely to exhibit site fidelity. The average tenure of a female at a specific site was nearly 8 days. [ABSTRACT FROM AUTHOR]

During the winter of 2014-15 in southern California, attempts were made to accelerate immature brown recluse spiders, Loxosceles reclusa Gertsch & Mulaik, 1940, to maturity for a pest control experiment in early spring. Despite food offerings, spiders stopped molting after October although they were maintained at 25° C and had swollen, well-nourished abdomens. It was surmised that decreased filtered daylight from a paper-covered window might be suppressing molting. Feeding was halted in January 2015; 88 spiderlings were checked weekly for molts. Molting resumed during late March 2015 and continued through May 2015 despite no feedings. To more thoroughly elucidate photoperiod effects on molting, during the week of the September 2015 equinox, three cohorts of 10 immatures of both brown and Chilean recluses, L. laeta (Nicolet, 1849), were exposed to three light regimes: 14:10 L:D, natural, 10:14 L:D. Through November 2015 to late March 2016 for brown recluses, there was no molting in the 10:14 regime, 3 of 10 spiders molted in the natural light regime, and 8 of 10 spiders molted in the 14:10 L:D regime. Additionally, fifteen newly-emerged brown recluse spiderlings split into three cohorts of 5 spiders each in November exhibited more molting in the 14:10 L:D compared to natural and 10:14 L:D light cycles. Chilean recluses showed no differences in molting across the three photoperiod regimes. This species difference may be explained in that brown recluses are native to temperate zones where winters can be fatal; Chilean recluses are tropical where short photoperiods may have little significance for survival. [ABSTRACT FROM AUTHOR]

The genus Loxosceles Heinecken & Lowe, 1832 has 91 representatives in the New World. Despite medical relevancy, the taxonomy of the genus is poorly understood. South American Loxosceles were divided into four groups of species: laeta, spadicea, gaucho and amazonica; this last one has a single species, Loxosceles amazonica Gertsch, 1967. More recently, the natural occurrence of L. amazonica in the New World has been questioned, due to the strong morphological resemblance and close phylogenetic relationship with Old World species, mainly with Loxosceles rufescens (Dufour, 1820). Herein, L. amazonica is rediagnosed and its morphological variation and natural distribution discussed. Two new species closely related to it from northeastern Brazil are also described, Loxosceles willianilsoni sp. n., from the state of Rio Grande do Norte, and Loxosceles muriciensis sp. n., from the state of Alagoas. The relationships of these new species with L. amazonica and L. rufescens are discussed. [ABSTRACT FROM AUTHOR]

Key Clinical Message The true danger of the spider bite stems from misdiagnosis and resultant delay in proper treatment of entities that, unlike spider bites, are not self-limited. Obtaining a complete exposure and travel history is central to the development of an accurate and appropriate differential diagnosis. [ABSTRACT FROM AUTHOR]

Background: The best-known dangerous spiders belong to the six genera. The genus Loxosceles or violin spiders are well known for their ability to cause skin necrosis or loxoscelism. All Loxosceles species have medical im- portance due to their necrotizing venom. The present article reports the occurrence of L. rufescens in Charkhab Cave, south of Iran (Larestan). Methods: The specimens were collected from the Charkhab Cave using handling forceps, paintbrush and aspirator and preserved in 96% ethanol. Results: Loxosceles rufescens, a medically important spider, is recorded from Charkhab Cave in Fars Province (southwest of Iran). Identification of L. rufescens was performed based on external morphology and the features of male genitalia. Conclusion: Presence of L. rufescens in south of Iran especially in a cave confirmed that this species is a widely distributed species in Iran. Therefore, cavers or cave visitors should be aware of this poisonous spider in caves. [ABSTRACT FROM AUTHOR]

A brown recluse spider (BRS) bite is challenging to confirm, but may be clinically diagnosed by considering the location, the season of the year, and the clinical manifestations. Here, the case of a 26-year-old male who presented after an insect bite with a skin lesion, bruising, severe swelling, and diffuse blisters on the right lower extremity after three days, is described. Following clinical examination, patient history assessment, and consideration of other relevant factors, the patient received a differential diagnosis of necrotizing fasciitis caused by BRS bite. Although spider bite poisoning is rare, proper diagnosis and management are important because, in some cases, the outcomes may be devastating.

The recluse spider Loxosceles rufescens (Dufour, 1820) was recorded for the first time from Ninawa, North of Iraq by Reimoser (1913). Now it is recorded for the second time from the locality of Abu-Alkhaseeb in Basrah south of Iraq. Both males and females were collected, their general habitus and genitalia are illustrated. New locality data of this species are also given. [ABSTRACT FROM AUTHOR]