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Ann Emerg Med 2019 Mar 26. Epub 2019 Mar 26.

Rocky Mountain Poison and Drug Center, Denver Health and Hospital Authority, Denver, CO.

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') antibody fragments. Read More

Toxicol Lett 2018 Dec 24;299:67-75. Epub 2018 Sep 24.

Faculdade de Farmácia, Universidade Federal da Bahia, Salvador, BA, Brazil; Instituto Gonçalo Moniz FIOCRUZ, Salvador, BA, Brazil. Electronic address:

The present study was undertaken to characterize the behavioral manifestations of nociception and the local mechanisms involved with the nociceptive response elicited by Latrodectus curacaviensis venom (LCV) in mice. After the intraplantar LCV inoculation, spontaneous nociception, mechanical and thermal nociceptive thresholds, motor performance, edema and cytokine levels were evaluated using von Frey filaments, hot/cold plate, rota-rod, plethismometer and ELISA, respectively. Analysis of LCV was performed by SDS-PAGE and chromatography. Read More

Am J Emerg Med 2018 Jun 6;36(6):998-1002. Epub 2017 Nov 6.

Denver Health and Hospital Authority, Rocky Mountain Poison and Drug Center, Denver, CO, USA; Department of Emergency Medicine, University of Colorado School of Medicine at Anschutz Medical Center, Aurora, CO, USA.

Background: Black widow species (Latrodectus species) envenomation can produce a syndrome characterized by painful muscle rigidity and autonomic disturbances. Symptoms tend to be more severe in young children and adults. We describe black widow spider exposures and treatment in the pediatric age group, and investigate reasons for not using antivenom in severe cases. Read More

Clin Toxicol (Phila) 2018 Jun 26;56(6):433-435. Epub 2017 Oct 26.

a Venom Systems & Proteomics Lab, School of Natural Sciences , National University of Ireland Galway , Galway, Republic of Ireland.

Objective: The noble false widow Steatoda nobilis is the only medically significant spider known to occur in the British Isles and Ireland, with a single case of steatodism ever reported from Great Britain. We present here five new cases of envenomations by S. nobilis, three from Ireland and two from Great Britain and describe symptoms not previously reported for the genus Steatoda. Read More

CJEM 2018 07 16;20(4):640-642. Epub 2017 Oct 16.

§Arnprior Hospital,Arnpior,ON.

Latrodectism following Black Widow envenomation is rare in Canada. We present the case of a previously healthy 50 year old male who presented with an acute abdomen, hypertension, and urinary retention. After a thorough work up it was determined to be as a result of a Black Widow spider bite. Read More

Toxins (Basel) 2017 04 21;9(4). Epub 2017 Apr 21.

Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Melbourne 3800, Australia.

Latrodectism or envenomation by widow-spiders is common and clinically significant worldwide. Alpha-latrotoxin is the mammalian-specific toxin in the venom that results in toxic effects observed in humans. Symptoms may be incapacitating and include severe pain that can persist for days. Read More

Toxicon 2017 May 27;130:63-72. Epub 2017 Feb 27.

Primera Cátedra de Toxicología, Facultad de Medicina, Universidad de Buenos Aires, Argentina.

"Black widow" spiders belong to the genus Latrodectus and are one of the few spiders in the world whose bite can cause severe envenomation in humans and domestic animals. In Argentina, these spiders are distributed throughout the country and are responsible for the highest number of bites by spiders of toxicological sanitary interest. Here, we studied the toxicity and some biochemical and immunochemical characteristics of eighteen venom samples from Latrodectus spiders from eight different provinces of Argentina, and the neutralization of some of these samples by two therapeutic antivenoms used in the country for the treatment of envenomation and by a anti-Latrodectus antivenom prepared against the venom of Latrodectus mactans from Mexico. Read More

J Egypt Soc Parasitol 2016 Apr;46(1):167-78

Spider bites are uncommon medical events, since there are limited number of spiders world-wide with fangs strong enough to pierce human skin, and most spiders bite humans only as a final defense when being crushed between skin and another object. Thus, most lesions attributed to spider bites are caused by some other etiology. The spiders that can cause medically significant bites include widow and false widow spiders (worldwide), recluse spiders (mostly North and South America), Australian funnel web spiders (eastern coastal Australia) and Phoneutria spiders (Brazil). Read More

Neurologia 2016 May 21;31(4):215-22. Epub 2015 Aug 21.

Servicio de Urgencias Pediátricas, Hospital Infantil del Estado de Sonora, Hermosillo, Mexico.

Introduction: Envenomation by black widow spiders manifests clinically with signs of neurotoxicity in paediatric patients.

Objective: Identify typical neurological signs and symptoms in paediatric patients of different ages, and describe treatment and outcomes in a paediatric hospital in northwest Mexico.

Material And Methods: We reviewed 70 clinical records of patients hospitalised due to black widow spider bite between 1978 and 2014. Read More

CJEM 2015 Sep 24;17(5):571-5. Epub 2015 Jul 24.

†Department of Emergency Medicine,School of Medicine,Loma Linda University,Loma Linda,CA.

Black widow spider envenomation generally results in self-limiting pain that can be treated in the emergency department (ED) with analgesics and benzodiazepines, usually with no further intervention. Occasionally, a patient has to be admitted or treated with antivenom for refractory pain or a venom-induced complication. We present the case of an 84-year-old man who presented to our ED with chest pain and dyspnea after being bitten on the foot by a western black widow spider (Lactrodectus hesperus). Read More

J Venom Anim Toxins Incl Trop Dis 2015 9;21:11. Epub 2015 May 9.

Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.

Background: The brown widow spider (Latrodectus geometricus Koch, 1841) has colonised many parts of the world from its continent of origin, Africa. By at least 1841, the species had successfully established populations in South America and has more recently expanded its range to the southern states of North America. This highly adaptable spider has been far more successful in finding its niche around the world than its famous cousins, the black widow, Latrodectus mactans, found in the south-eastern states of North America, and the red-back, Latrodectus hasselti, found mostly in Australia, New Zealand and Japan. Read More

Perm J 2014 ;18(4):e155-8

Epidemiologist in the Emergency Operation Center at the Hellenic Center for Disease Control and Prevention in Athens, Greece.

During the summer period 2011-2012, seven widow spider bites in Greece were reported to the Hellenic Center for Disease Control and Prevention. Widow spiders (in the genus Latrodectus) are found all over the world, including Europe, Asia, Africa, Australia, and the US. Alpha-latrotoxin (main mammalian toxin) causes the toxic effects observed in humans. Read More

Pediatr Emerg Care 2014 Oct;30(10):723-4

From the *Department of Pediatric Emergency Medicine, Children's Healthcare of Atlanta and †Emory University School of Medicine, Atlanta, GA.

Priapism, although uncommon in preadolescent children, is considered a true emergency. Envenomation by a black widow spider bite has been reported to induce priapism as a manifestation of its toxicity. Early recognition and timely administration of antivenin have been reported to be effective in relieving priapism. Read More

J Emerg Nurs 2014 Mar;40(2):193-4

Washington, DC. Electronic address:

Wilderness Environ Med 2014 Mar 10;25(1):80-1. Epub 2014 Jan 10.

Department of Emergency Medicine, Loma Linda University School of Medicine, Loma Linda, CA.

Priapism in children after a black widow spider bite is a rare phenomenon with only a few case reports noted in the literature. Black widow bites are commonly associated with pain, muscle cramping, hypertension, and tachycardia. Initial treatment includes pain control with opiate or opioid medications and benzodiazepines, with antivenom reserved for severe cases of envenomation manifested by uncontrolled pain or hypertension. Read More

Crit Care Nurs Clin North Am 2013 Jun;25(2):205-23

Department of Entomology, University of California, Riverside, Riverside, CA 92521, USA.

In North America, spider envenomation is perceived to be a greater threat than in actuality; however, it still is a valid source of morbidity and, very rarely, mortality. Only 2 groups (widows, recluses) are medically important on this continent. Widow bites affect the neuromuscular junction, have minor dermatologic expression, and are treated with analgesics and antivenom. Read More

Clin Toxicol (Phila) 2013 Mar;51(3):191-2

Ann Emerg Med 2013 Apr 4;61(4):458-67. Epub 2013 Feb 4.

Denver Health and Hospital Authority/Rocky Mountain Poison & Drug Center, Denver, CO, USA.

Study Objective: Black widow spider antivenom has never been tested in a randomized clinical trial, to our knowledge. We explore various efficacy measures for a novel F(ab)2 antivenom in patients with moderate to severe pain caused by black widow spider envenomation.

Methods: A randomized, placebo-controlled, double-blind, clinical trial was conducted in 12 academic emergency departments. Read More

Mol Biol Evol 2013 May 21;30(5):999-1014. Epub 2013 Jan 21.

Department of Biological Sciences, University of Massachusetts, Lowell, USA.

Black widow spiders (members of the genus Latrodectus) are widely feared because of their potent neurotoxic venom. α-Latrotoxin is the vertebrate-specific toxin responsible for the dramatic effects of black widow envenomation. The evolution of this toxin is enigmatic because only two α-latrotoxin sequences are known. Read More

J Fam Pract 2012 Nov;61(11):694-5

Valley Family Medicine Residency, Renton, WA, USA.

Opioids relieve pain and benzodiazepines ease muscle spasms in most patients with latrodectism-widespread, sustained spasms-resulting from envenomation by a black widow spider. Read More

J Med Entomol 2012 Jul;49(4):947-51

Department of Entomology, University of California, Riverside, CA 92521, USA.

The brown widow spider, Latrodectus geometricus C. L. Koch, has become newly established in southern California during the first decade of the 21st century. Read More

Wilderness Environ Med 2012 Jun 10;23(2):158-60. Epub 2012 Apr 10.

Department of Neurology, Wake Forest Baptist Health, Winston-Salem, NC, USA.

Horner's syndrome involves a triad of eyelid ptosis, miosis, and facial anhidrosis that results from disruption of the oculosympathetic pathway. Acquired Horner's syndrome is associated with a variety of medical conditions including Pancoast tumor and carotid dissection. We report the unique case of a 47-year-old man presenting with Horner's syndrome 4 weeks after black widow spider envenomation. Read More

Curr Pharm Biotechnol 2012 Aug;13(10):1935-9

Division of Toxicology, Rocky Mountain Poison & Drug Center, 990 Bannock St., Denver, CO 80204, USA.

Black widow spider (Latrodectus mactans) envenomation has been recognized since antiquity. The syndrome, latrodectism, is characterized by painful muscle rigidity and autonomic disturbances such as tachycardia, hypertension, and diaphoresis. Symptoms typically last for 1-3 days. Read More

Case Rep Med 2012 26;2012:794540. Epub 2012 Jan 26.

Medical Intensive Care Unit, Ibn Sina University Hospital, 10000 Rabat, Morocco.

Black widow spiders can cause variable clinical scenarios from local damage to very serious conditions including death. Acute myocardial damage is rarely observed and its prognostic significance is not known. We report a rare case of a 35-year-old man who developed an acute myocarditis with cardiogenic pulmonary edema requiring mechanical ventilation caused by black widow spider's envenomation. Read More

Clin Toxicol (Phila) 2012 Jan 19;50(1):70-3. Epub 2011 Dec 19.

Department of Emergency Medicine, Keck School of Medicine, University of Southern California, Section of Toxicology, Los Angeles County-USC Medical Center, 1200 North State Street, Los Angeles, USA.

Objectives: Following widow spider (Latrodectus sp.) envenomation, local pain, erythema, abdominal pain, rigidity, hypertension, and diaphoresis can be seen. While an effective specific antivenom (AV) is available, its use is limited due to concern of possible severe allergic reaction. Read More

Ann Pharmacother 2011 Dec 24;45(12):1491-8. Epub 2011 Nov 24.

School of Medicine, University of Colorado Denver, Aurora, CO, USA.

Background: Black widow spider (Latrodectus spp.) envenomation remains the most clinically significant spider envenomation in the US. The syndrome is characterized by painful muscle rigidity and autonomic disturbances. Read More

Perm J 2011 ;15(3):76-81

Black widow spiders (Latrodectus mactans) are found throughout the US. Though bites are relatively uncommon, they pose a significant health problem with over 2500 reported to American poison control centers annually. Black widow spider bites cause a characteristic envenomation syndrome consisting of severe pain, muscle cramping, abdominal pain, and back pain. Read More

J Med Toxicol 2011 Dec;7(4):317-21

Department of Emergency Medicine, Carolinas Medical Center, Charlotte, NC 28232, USA.

Latrodectus mactans antivenin is a safe and effective therapy for severe black widow spider envenomations when given to most patients. We report a case of a 37-year-old male with a history of asthma that was given L. mactans antivenin for symptoms related to a black widow envenomation and developed a severe anaphylactic reaction resulting in cardiac arrest. Read More

Biochem Pharmacol 2012 Jan 5;83(1):170-83. Epub 2011 Oct 5.

Neurotoxin Research Group, School of Medical & Molecular Biosciences, University of Technology, Sydney, NSW, Australia.

The venom of the European black widow spider Latrodectus tredecimguttatus (Theridiidae) contains several high molecular mass (110-140 kDa) neurotoxins that induce neurotransmitter exocytosis. These include a vertebrate-specific α-latrotoxin (α-LTX-Lt1a) responsible for the clinical symptoms of latrodectism and numerous insect-specific latroinsectoxins (LITs). In contrast, little is known about the expression of these toxins in other Latrodectus species despite the fact that envenomation by these spiders induces a similar clinical syndrome. Read More

Lancet 2011 Dec 15;378(9808):2039-2047. Epub 2011 Jul 15.

Centro de Desenvolvimento Cultural, Instituto Butantan, São Paulo, Brazil.

Spiders are a source of intrigue and fear, and several myths exist about their medical effects. Many people believe that bites from various spider species cause necrotic ulceration, despite evidence that most suspected cases of necrotic arachnidism are caused by something other than a spider bite. Latrodectism and loxoscelism are the most important clinical syndromes resulting from spider bite. Read More

Am J Emerg Med 2012 Jun;30(5):836.e1-2

Rocky Mountain Poison and Drug Center, Denver Health, Denver, CO 80204, USA.

Black widow spider envenomation is commonly reported to poison centers. Black widow spider envenomation produces a clinical syndrome, known as latrodectism, characterized by headache, nausea, vomiting, several muscle cramping and pain, joint stiffness, hypertension, and regional diaphoresis. Black widow spider antivenom (Merck & Co, Inc, West Point, PA USA) is an effective and relatively safe treatment option. Read More

J Matern Fetal Neonatal Med 2011 Jan 12;24(1):122-6. Epub 2010 May 12.

Department of Obstetrics and Gynecology, Division of Maternal Fetal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131-0001, USA.

Objective: Little data exist regarding the optimal treatment and outcomes of pregnancies complicated by black widow spider envenomation. Our objective is to evaluate the clinical effects, medical outcomes, and treatment differences between pregnant and nonpregnant women.

Methods: This observational study is based on a review of the database maintained by the American Association of Poison Control Centers from 2003 to 2007. Read More

Am Fam Physician 2009 Oct;80(8):793-802

Women's and Children's Hospital, North Adelaide, South Australia, Australia.

About 4,000 to 6,000 venomous snakebites occur each year in the United States. Although these envenomations (also known as envenomings) are rarely fatal, about 70 percent require antivenom therapy. Few evidence-based guidelines are available for the management of envenomation. Read More

Am J Emerg Med 2009 Jul;27(6):759.e1-2

Department of Emergency Medicine, Maricopa Medical Center, Phoenix, AZ 85008, USA.

Ann Fr Anesth Reanim 2009 Mar 19;28(3):260-1. Epub 2009 Mar 19.

Clin Toxicol (Phila) 2009 Apr;47(4):356-7

Metro Health/Michigan State University College of Osteopathic Medicine Program in Emergency Medicine, Grand Rapids, USA.

A 17-year-old male was envenomated on the right forearm by a black widow spider that had presumably traveled in a packaged dishwasher and been shipped from Mexico to Michigan. The patient experienced vomiting and severe pain in his abdomen and chest approximately 30 min after being bitten. He received 6000 units (1 vial) of Latrodectus antivenin intravenously about 7 h after he was envenomated. Read More

South Med J 2008 Dec;101(12):1269-70

Mississippi Department of Health, and the Mississippi State University Extension Service, Jackson, MS 39215, USA.

The brown widow, Latrodectus geometricus, is one of five species of Latrodectus in the United States, and is reported to be one of the least dangerous. However, we report a previously healthy patient bitten by a brown widow, resulting in a serious reaction requiring hospitalization. Symptoms included severe pain, cramps, nausea/vomiting, and fasciculations in the pectoral and quadriceps muscles. Read More

Am J Emerg Med 2008 Jun;26(5):630.e1-3

Department of Cardiology, Gaziantep University School of Medicine, Gaziantep TR-27310, Turkey.

The black widow spider (BWS), which is a member of the arthropod family, is widely distributed on earth. Black widow spider bites can cause a wide variety of signs or symptoms in humans, but the cardiovascular manifestations are relatively rare except hypertension/hypotension and bradycardia/tachycardia. We report on a 65-year-old man who experienced myocarditis after BWS envenomation, which is extremely rare. Read More

Toxicon 2008 Mar 23;51(4):547-54. Epub 2007 Nov 23.

Institute of Microbiology, Catholic University, Rome, Italy.

Alpha-latrotoxin (alpha-ltx), a component of the venom of black widow spiders (BWSV), binds to higher vertebrates presynaptic nerve terminals, stimulating massive neurotransmitter release. This neurotoxic protein is responsible for most of the symptoms elicited in men by the bite of black widow spider (BWS), i.e. Read More

J Med Toxicol 2006 Mar;2(1):46-7

Annu Rev Entomol 2008 ;53:409-29

Department of Entomology, University of California, Riverside, CA 92521, USA.

Spiders have been incriminated as causes of human suffering for centuries, but few species worldwide cause medically significant envenomation. Widow spiders (Latrodectus spp.) occur worldwide and cause latrodectism, which is characterized by pain (local and generalized) associated with nonspecific systemic effects, diaphoresis, and less commonly other autonomic and neurological effects. Read More

Ann Saudi Med 1999 Jan-Feb;19(1):15-9

King Fahad Hospital at Al Baha, Al Baha, Saudi Arabia.

Background: The purpose of this study was to highlight the clinical features of spider bite envenomation, a subject which has not, to our knowledge, been previously published in Saudi Arabia.

Patients And Methods: Ten patients (8 males and 2 females) aged between 13 and 75 years (mean 36.8) were hospitalized at King Fahad Hospital, Al Baha, with the diagnosis of spider bites during the 9-year period from June 1988 to May 1997. Read More

Clin Tech Small Anim Pract 2006 Nov;21(4):187-90

Reid Veterinary Hospital, 933 SW Queen Avenue, Albany, OR 97321, USA.

Black widow spiders are found throughout the continental United States and north into the southern Canadian provinces. Male black widow spiders are of little medical importance. Female black widow spiders can be 20 times larger than males. Read More

Presse Med 2006 Dec;35(12 Pt 1):1825-7

Centre Antipoison, Hôpital Salvator, Marseille.

Introduction: Cobweb spiders (genus Steatoda) are small species closely related to black widow spiders and their bites can induce envenomation known as steatodism.

Case: A 46-year-old man in the Gard district in southern France was sleeping in his bed when a spider (identification Steatoda triangulosa) bit him. Clinical manifestations included local signs together with systemic neurological symptoms resembling low-grade latrodectism (black widow envenomation). Read More

Gac Med Mex 2006 Mar-Apr;142(2):103-8

Servicio de Medicina Interna, Hospital Infantil del Estado de Sonora, Hermosillo, Sonora, Mexico.

Introduction: Poisoning caused by "black widow" spider bite, is not commonly observed during childhood, it is not exempt from complications, and must be treated in time or the patient can die. In Mexico we do not have accurate data on the exact number of accidents due to this condition.

Objective: Identify the signs and characteristic symptoms of children treated at the Children's Hospital from the state of Sonora with the aim of starting early treatment. Read More

Presse Med 2005 Jan;34(1):49-56

Centre antipoison, hôpital Salvator, Marseille.

LIMITED RISKS: Although most species of spiders are venomous, only ten or so are able to induce human envenomations. From a systematic point of view, it is possible to distinguish the araneomorph spiders - or "true" spiders - from the mygalomorph spiders. Dangerous species for humans can be found in both groups. Read More

Pediatrics 2004 Jul;114(1):e128-9

Division of Critical Care, Children's Healthcare of Atlanta at Egleston, Atlanta, Georgia 30322, USA.

Black widow spider envenomation (BWSE) is commonly associated with severe abdominal pain, muscle cramping, and hypertension. Treatment is primarily symptomatic with the use of opiates and benzodiazepines. Priapism is a complication of BWSE that has only rarely been reported. Read More

Air Med J 2004 Jul-Aug;23(4):24-6

Vanderbilt Lifeflight, Nashville, Tenn., USA

A request to transport a patient with an arachnid envenomation may not be one of the most common calls the transport team receives, yet an understanding of how to care for such patients can decrease complications and prevent morbidity and mortality. This case outlines a systemic reaction from a black widow spider bite and discusses its subsequent management from initial assessment in the referring emergency department (ED) to discharge. Read More

Emerg Med Clin North Am 2004 May;22(2):405-22, ix

University of Vermont School of Medicine, Burlington 05405, USA.

This article focuses on the medically relevant arachnid species found in North America and selected other arachnids from around the world. While it is largely still true that the geographic location of the envenomation assists in determining the species responsible, the booming trade in arachnids as exotic pets should prompt the clinician to inquire into this possibility. Expert advice should be sought in either case; species identification is critical in determining the need for and proper type of antivenom therapy. Read More