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

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).

It's Not a Spider Bite-It's MRSA!

Although there is an increased awareness of community-acquired methicillin-resistant Staphylococcus aureus (MRSA), there remains a bias of the public and health-care workers to blame spiders as a cause of skin and soft tissue infection when there is no valid incriminated evidence for this assumption. MRSA is a formidable infection and remains a threat to human health. Recognition and proper treatment by practitioners remain of utmost importance to improve patient outcomes.

Evolution in the choice of therapies used to treat latrodectism: Redback spider antivenom or standard analgesic medications. Nothing to rave about.

OBJECTIVES: Redback spider (RBS) antivenom (RBSAV) use appears to have decreased since the results of the RAVE-2 antivenom efficacy study were released. The aims of this study were to assess change in RBSAV use over time and compare responses to treatment for antivenom and other analgesics. METHODS: Retrospective audit of RBS bite referrals to a toxicology unit, from January 2010 to January 2022. Data included demographics, pain severity, treatment (analgesia or RBSAV), response to treatment, re-presentation rate, adverse events, change in antivenom use over time. RESULTS: Of 270 presentations, 157 with moderate or severe pain were included (RBSAV n = 51, analgesia n = 106). Median age was 39 years, n = 81 (51%) female. Those receiving antivenom were more likely to report severe pain n = 46/51 (84%) versus n = 68/106 (58%) (P = 0.006). Eighty-three percent of antivenom doses were administered between 2010 and 2013. Analgesia-only group received various combinations of paracetamol, NSAIDs, and opioids. In those receiving RBSAV, 17/48 (35%), 26/48 (54%), 5/48 (10%) reported a partial, complete or no reduction in pain, respectively, versus 30/77 (39%), 43/77 (58%) and 4/77 (5%), for analgesia-only group. Post-treatment pain was not recorded in three RBSAV and 28 analgesia-only patients. Pain reduction was no different for intravenous and intramuscular antivenom. Re-presentation for ongoing pain was more common in the analgesia-only group, 16/106 (15%) versus 1/51 (2%) for antivenom (P = 0.013). CONCLUSION: Antivenom use fell over the study period. There was no difference in pain relief between RBSAV and analgesia-only groups. RBSAV, regardless of route of administration, was no better than standard analgesics in pain reduction in the present study.

Impact of antivenom administration on the evolution of cutaneous lesions in loxoscelism: A prospective observational study.

BACKGROUND: Spiders of the genus Loxosceles are distributed throughout tropical and temperate regions worldwide. Loxosceles spp. bites may evolve to necrosis, with or without intravascular hemolysis. There is no consensus regarding the best treatment to prevent necrosis. The objective of this study was to evaluate the factors associated with the development of necrosis and the impact that antivenom administration has on the evolution of cutaneous loxoscelism. METHODOLOGY/PRINCIPAL FINDINGS: This was a prospective observational study carried out at a referral center for envenoming. Over a 6-year period, we included 146 patients with a presumptive or definitive diagnosis of loxoscelism. Depending on the symptom severity, a polyvalent anti-arachnid antivenom was administered or not-in 74 cases (50.7%) and 72 cases (49.3%), respectively. Cutaneous and systemic manifestations were assessed at admission and weekly thereafter. Adverse reactions to the antivenom were also evaluated. Cutaneous loxoscelism was observed in 141 cases (96.6%), and the spider was identified in 29 (19.9%). The mean time from bite to antivenom administration was 41.6 ± 27.4 h. After discharge, 130 patients (90.9%) were treated with corticosteroids, antihistamines and analgesics being prescribed as needed. The probability of developing necrosis was significantly lower among the patients who were admitted earlier, as well as among those who received antivenom (p = 0.0245). Among the 74 patients receiving antivenom, early and delayed adverse reactions occurred in seven (9.5%) and four (5.4%), respectively. Local infection was observed only in three (2.3%) of the 128 patients for whom that information was available. CONCLUSIONS/SIGNIFICANCE: Necrosis after a Loxosceles sp. bite appears to more common when hospital admission is delayed or when antivenom is not administered. In addition, the administration of a polyvalent anti-arachnid antivenom appears to be safe, with a relatively low rate of adverse reactions.

Diethyl Azelate for the Treatment of Brown Recluse Spider Bite, a Neglected Orphan Indication.

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 dose-dependent manner. CONCLUSION: DEA is a promising novel therapy for the brown recluse spider bite and perhaps even unrelated envenomations involving PLDs.

Redback spider bites in children in South Australia: A 10-year review of antivenom effectiveness.

OBJECTIVE: To describe the South Australian paediatric redback spider bite experience and to examine the hypothesis that redback antivenom (RBAV) treatment in children is clinically effective. METHODS: Retrospective chart review of all children under 18 years of age presenting to the EDs of the three major paediatric or mixed hospitals in Adelaide, South Australia, with a discharge diagnosis of redback spider envenomation between 1 January 2010 and 31 March 2020. The main outcome measures include: patient and bite demographics; presenting symptoms and signs; treatment provided; clinical effects at 2 h post RBAV administration on pain, diaphoresis, blood pressure, heart rate and systemic features; overall clinical impression of RBAV effectiveness and resolution of symptoms prior to discharge. RESULTS: There were 256 patient encounters involving 235 patients. Latrodectism was described in one-third (34%) of the cases. Sixty-one patients received RBAV and in 57 (93%) patients the RBAV had good clinical effect. Two hours post RBAV administration, pain resolved in 71%, hypertension resolved in 62%, diaphoresis resolved in 43% and tachycardia resolved in 82%. There were no cases of urticaria or anaphylaxis and one case of serum sickness. CONCLUSIONS: This retrospective review of redback spider envenomation in South Australian children over a 10-year period has demonstrated clinical effectiveness of RBAV in paediatric patients across all age groups, observed in both clinician perceived results and measurable outcomes. RBAV remains an effective treatment for redback envenomation in children.

Picadura de la araña reclusa / Bite of recluse spider

No disponible

A Review of Black Widow (Araneae: Theridiidae) Envenomation, Epidemiology, and Antivenom Utilization in Canada.

Two species of black widow spider (BWS-Latrodectus hesperus Chamberlin & Ivie and Latrodectus variolus Walckenaer) naturally occur in Canada and are capable of causing deleterious envenomation to humans. No Canadian literature exists on the frequency of envenomations by these species or the use of antivenom in the treatment of those patients. A review of primary Canadian arachnology data was undertaken to identify BWS populations. A retrospective review of the Health Canada Special Access Program records generated epidemiology and the utilization of antivenom for BWS envenomations in Canada. The geographical distribution of BWS species is limited to along the southern Canadian border. From January 2009 to December 2015, there were five BWS envenomations that required treatment with antivenom and all cases occurred in British Columbia. An average patient age of 41 yr ± 21 SD (range 7-59) was observed, along with three of the five patients being female. The average number of vials used for treatment was 2 ± 1 SD (range 1-3). BWS Antivenin was also obtained by facilities in Alberta, Ontario, and Nova Scotia, but not used in any of these jurisdictions. Further investigation is necessary to determine the annual incidence of BWS envenomations and if treatment with BWS antivenin is required.

Latrodectus geometricus (Aranea: Theridiidae) envenoming: Rapid resolution of symptoms following F(ab')2 antivenom therapy.

The Brown Widow spider (Latrodectus geometricus) is an invasive species whose geographic range has been expanding worldwide. It is a relative species of the Black Widow and Red-backed spiders of the genus Latrodectus. Despite its broad geographic distribution cases of Brown Widow envenomation have rarely been documented. The venom of L. geometricus is similar to the venom of L. mactans with the primary venom component being alpha-latrotoxin, and consequent envenoming by L. geometricus to humans has resulted in symptoms similar to those reported for other Latrodectus spp. Specific FDA approved Latrodectus antivenom (IgG) available in North America has been effectively used in treating venom-induced symptoms following L. mactans envenoming. The patient reported here involved a confirmed L. geometricus envenoming who was efficaciously treated with an alternately available F(ab')2 antivenom from Mexico.

Latrodectism in Italy: First report of successful treatment of L. tredecimguttatus envenomation using L. mactans antivenom from North America.

INTRODUCTION: Latrodectism is a rare, but potentially severe, clinical syndrome caused by spider of the genus Latrodectus. L. tredecimguttatus is widespread in Italy and its bite cause the injection of α-latrotoxin that cause depletion of acetylcholine at motor nerve endings and release of catecholamines at adrenergic nerve endings. We describe the first clinical case of L. tredecimguttatus poisoning successfully treated with L. mactans antivenom from North America. CASE REPORT: A healthy 60-year-old patient was admitted to the emergency department after unknown insect sting or arachnid/snake bite. In the early morning, the patient was working in the countryside when he felt a sting-like pain in the medial area of the right lower leg, associated with an intense burning sensation. An hour later he developed agitation, hoarseness, sweating, abdominal distress and intense pain in his right leg. In the emergency room vital signs showed a hypertensive crisis, tachycardia and peripheral oxygen desaturation. ECG was normal and ABE showed mixed acid-base disorder. Blood tests showed leukocytosis with neutrophilia, high levels of myoglobin, with normal coagulation and normal plasmatic cholinesterase. Neck, thorax and abdomen CT scan, with and without contrast medium, was negative. Four hours after admission hypertension worsened with board like rigid abdomen and onset of fasciculations, tremors, miosis and intense regional sweating. The definitive diagnosis of poisoning by L tredecimguttatus was based on the clinical picture. Within short time the antidote was provided by the Poison Centre and administered. A marked improvement of the symptomatology was noted after 30 minutes, and 1 hour later all symptoms were under control. The patient was discharged after 2 days. CONCLUSIONS: The clinical presentation of a patient suffering from latrodectism places the clinician in front of a challenging differential diagnosis. Following the suspicion, the first-line doctor is invited to discuss the case with a toxicologist, in order to confirm or exclude the diagnosis and implement all therapeutic measures. In our clinical case, the absence of organic lesions, laboratory tests not suggestive for other causes, and the presence of typical clinical feature suggested the diagnosis of L tredecimguttatus poisoning. This hypothesis was then supported by the close temporal relation between antivenom administration and symptoms improvement. With this case, we report the first use of L mactans antivenom from North America to treat L.tredecimguttatus poisoning and we confirm its effectiveness in counteracting latrodectism caused by this spider.

Forty Years of the Description of Brown Spider Venom Phospholipases-D.

Spiders of the genus Loxosceles, popularly known as Brown spiders, are considered a serious public health issue, especially in regions of hot or temperate climates, such as parts of North and South America. Although the venoms of these arachnids are complex in molecular composition, often containing proteins with distinct biochemical characteristics, the literature has primarily described a family of toxins, the Phospholipases-D (PLDs), which are highly conserved in all Loxosceles species. PLDs trigger most of the major clinical symptoms of loxoscelism i.e., dermonecrosis, thrombocytopenia, hemolysis, and acute renal failure. The key role played by PLDs in the symptomatology of loxoscelism was first described 40 years ago, when researches purified a hemolytic toxin that cleaved sphingomyelin and generated choline, and was referred to as a Sphingomyelinase-D, which was subsequently changed to Phospholipase-D when it was demonstrated that the enzyme also cleaved other cellular phospholipids. In this review, we present the information gleaned over the last 40 years about PLDs from Loxosceles venoms especially with regard to the production and characterization of recombinant isoforms. The history of obtaining these toxins is discussed, as well as their molecular organization and mechanisms of interaction with their substrates. We will address cellular biology aspects of these toxins and how they can be used in the development of drugs to address inflammatory processes and loxoscelism. Present and future aspects of loxoscelism diagnosis will be discussed, as well as their biotechnological applications and actions expected for the future in this field.

The Efficacy of Antivenin Latrodectus (Black Widow) Equine Immune F(ab')2 Versus Placebo in the Treatment of Latrodectism: A Randomized, Double-Blind, Placebo-Controlled, Clinical Trial.

STUDY OBJECTIVE: The antivenom currently available for treatment of systemic black widow envenomation (latrodectism) is composed of equine whole immunoglobin. Although considered effective, it has been associated with anaphylaxis and 2 reported fatalities. We test the efficacy and safety of new equine antivenom composed of purified F(ab')2 antibody fragments. METHODS: A randomized, double-blind, placebo-controlled trial was conducted at 16 sites across the United States. Subjects aged 10 years or older with moderate to severe pain because of black widow spider envenomation received F(ab')2 antivenom or placebo. The primary outcome measure was treatment failure, which was defined as failure to achieve and maintain clinically significant reduction in pain for 48 hours posttreatment. Secondary measures of pain intensity differences and summed pain intensity difference were computed. Adverse events were recorded. RESULTS: Sixty patients were treated (29 antivenom and 31 placebo). The mean age was 39 years and 68% were male. There were 15 treatment failures in the antivenom group and 24 in the placebo group (P=.019). Differences in pain intensity difference between groups were lower at each postbaseline point, and the mean summed pain intensity difference was greater for the antivenom group (difference 2,133; 95% confidence interval 177 to 4,090). No deaths or serious drug-related adverse events were detected. CONCLUSION: The F(ab')2 antivenom met the predefined primary outcome of reduced treatment failures. Secondary outcomes of pain intensity difference and summed pain intensity difference also supported efficacy. The rate of symptom improvement in the placebo group was higher than expected, which may be related to enrollment criteria or placebo effect.

Targeting Loxosceles spider Sphingomyelinase D with small-molecule inhibitors as a potential therapeutic approach for loxoscelism.

Loxosceles spiders' venoms consist of a mixture of proteins, including the sphingomyelinases D (SMases D), which are the main toxic components responsible for local and systemic effects in human envenomation. Herein, based on the structural information of SMase D from Loxosceles laeta spider venom and virtual docking-based screening approach, three benzene sulphonate compounds (named 1, 5 and 6) were identified as potential Loxosceles SMase D inhibitors. All compounds inhibited the hydrolysis of the sphingomyelin substrate by both recombinant and native SMases D. Compounds 5 and 6 acted as SMases D uncompetitive inhibitors with Ki values of 0.49 µM and 0.59 µM, respectively. Compound 1 is a mixed type inhibitor, and presented a Ki value of 0.54 µM. In addition, the three compounds inhibited the binding of SMases D to human erythrocytes and the removal of glycophorin C from the cell surface, which are important events in the complement-dependent haemolysis induced by Loxosceles venom. Moreover, compounds 5 and 6 reduced the binding of SMases to human keratinocytes membrane and the venom induced cell death. Importantly, compounds 5 and 6 also controlled the development of the necrotic lesion in an in vivo model of loxoscelism. Together, our findings indicate that the novel SMase D inhibitors presented here are able to suppress both local and systemic reactions induced by Loxosceles venoms. Since the number of Loxosceles envenomation accidents is currently growing worldwide, our results indicate that both inhibitors are promising scaffolds for the rational design of new drugs targeting SMases D from these spiders.

Brown Recluse Spider Bites in Patients With Neutropenia: A Single-institution Experience.

Brown recluse spider bites can cause local and systemic signs, including rash, dermonecrosis, edema, hemolysis, and acute kidney failure. These are mostly attributed to sphingomyelinase D, the main toxin. To evaluate the severity of the disease in pediatric patients with and without neutropenia, we retrospectively reviewed records of patients treated at St. Jude Children's Research Hospital between 1970 and 2015 and identified 19 patients who met the inclusion criteria. Variables of interest included the type of underlying illness, presence of neutropenia, number of days of hospitalization, disease signs and outcome of the bite, and treatments administered. We used descriptive statistics to summarize the manifestations and severity of spider bites in patients with and without neutropenia. Six patients experienced pain from the bite, 11 had erythema, 7 developed edema, and 5 had fever. The response to spider bites in neutropenic patients was no milder than that in non-neutropenic individuals. Six patients developed systemic complications. Compared with non-neutropenic patients, neutropenic patients had antibiotics prescribed more often and experienced longer hospital stays. Spider bites do not seem to have a different clinical course in neutropenic patients. Therefore, a conservative approach may be best for these patients, with close monitoring and local wound care.