ArticlePDF AvailableLiterature Review

Abstract and Figures

More than 40,000 species of spiders have been identified in the world. Spider bites is a common problem among people, however few of them are harmful but delay in treatment can cause death. Since the spider bites are risk full to human, they should be taken seriously, especially in endemic areas. Our objective in this review was to study about poisonous spiders and find out treatments of them. Therefore we collected related articles from PubMed database and Google Scholar. Three important syndromes caused by spider bites are loxoscelism, latrodectism and funnel web spider syndrome. Many treatments are used but much more studies should have done to decrease the mortality. In this review, we describes different venomous spiders according to their ap- pearance, symptoms after their bites and available treatments.
Content may be subject to copyright.
Copyright © 2014 Shahid Beheshti University of Medical Sciences. All rights reserved.
Downloaded from:
Emergency (2014); 2 (2): 54-58
Poisonous Spiders: Bites, Symptoms, and Treatment; an Educational Review
Farzad Rahmani1*, Seyed Mahdi Banan Khojasteh2, Hanieh Ebrahimi Bakhtavar3, Farnaz Rahmani4,
Kavous Shahsavari Nia5, Gholamreza Faridaalaee6
1. Department of Emergency medicine, Tabriz University of Medical Sciences, Tabriz, Iran
2. Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran
3. Department of Emergency Medicine, Ardabil University of Medical Sciences, Ardabil, Iran
4. Department of Psychiatric Nursing, School of Nursing and Midwifery, Tabriz University of Medical Sciences, Tabriz, Iran
5. Road Traffic Injury Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
6. Department of Emergency Medicine, Urmia University of Medical Sciences, Urmia, Iran
More than 40,000 species of spiders have been identified in the world. Spider bites is a common problem among
people, however few of them are harmful but delay in treatment can cause death. Since the spider bites are risk
full to human, they should be taken seriously, especially in endemic areas. Our objective in this review was to
study about poisonous spiders and find out treatments of them. Therefore we collected related articles from
PubMed database and Google Scholar. Three important syndromes caused by spider bites are loxoscelism,
latrodectism and funnel web spider syndrome. Many treatments are used but much more studies should have
done to decrease the mortality. In this review, we describes different venomous spiders according to their ap-
pearance, symptoms after their bites and available treatments.
Key words: Spiders, spider bites, spider venoms, black widow spider, emergency treatment
Cite This Article as: Rahmani F, Banan Khojasteh M, Ebrahimi Bakhtavar H, Rahmani F, Shahsavari Nia K, Faridaalaee GH.
Poisonous Spiders: Bites, Symptoms, and Treatment; an Educational Review. Emergency. 2014;2(2):54-8
piders belong to a branch of invertebrate animals
called arthropods. Arthropods have the largest
number of species. Along with ticks, mites and
scorpions, spiders fall into the subphylum chelicerata
and class of arachnids (1, 2). The arachnid class has
very diverse members in a way that more than 80,000
species belonging to that class have been identified to
date. Spiders are a large group of arachnids belonging
to the araneae order (1). More than 40,000 species of
spider have been identified to date but the real number
is estimated at 4 times more than that number (3). Ex-
cept for two small groups in the arachnid family, all spi-
ders have poison glands and release their secretions
into their venom sacs near their chelicerae. However,
the majority of spiders do not bite humans and except
for a few cases, they are not harmful to the human being
or other mammals (2).Spider bites are common but the
majority of species create little clinical presentations
(3). There is only one aggressive spider named funnel-
web in Australia which attacks the human being with-
out provocation. The majority of venomous spiders are
found in Latin America. These large spiders are quite
*Corresponding Author: Farzad Rahmani, MD; Emergency Medicine Depart-
ment, Imam Reza Hospital, Tabriz University of Medical Sciences, Golgasht
Avenue, Tabriz, Iran. Postal code: 5166614756.
Phon/Fax: 00984113352078. Email:
Received: 7March 2014; Accepted: 27 Ma rch 2014
aggressive and their venom is pharmacologically highly
toxic. Their bite results in severe pain, neurotoxic ef-
fects, diaphoresis, severe allergic reaction and priapism
(1). Other spiders normally exhibit aggressive behavior
after being trapped, injured or provoked. The severity
of reactions to spider venom depends on factors such as
its amount, site of biting and its duration and also age
and health condition. Mortality due to spider bite is rare
(2). Spider venom includes different peptides and sub-
stances affecting sodium, calcium and potassium chan-
nels in neurons and also glutamate and acetylcholine
receptors (4).Spider bite victims develop symptoms
such as pain and swelling in the site of biting, necrosis,
pyrexia, pulmonary edema, respiratory distress, hyper-
tension, kidney dysfunction and death. Treatment pro-
tocol in the case of critically ill patients includes sup-
portive measures and antivenom injection. Respiratory
support and monitoring the hemodynamic status of
these patients are of fundamental importance (5). High-
ly venomous spiders, funnel-web in Australia and ar-
madeiras (armed spiders) in South America require
antivenom and intensive therapeutic interventions (6).
Three important syndromes are caused by spider bites:
latrodectism, loxoscelism, and funnel-web spider syn-
drome (7). Here, we discuss about poisonous spiders
and find out treatments of them.
Copyright © 2014 Shahid Beheshti University of Medical Sciences. All rights reserved.
Downloaded from:
Rahmani et al
Figure 1: Flowchart of study
Introduction of venomous spiders
This section describes different venomous spiders ac-
cording to their appearance, symptoms after their bites
and available treatments. Therefore we collected relat-
ed articles from PubMed and Google scholar (Figure 1).
a) The brown recluse spider
The brown recluse spider is recognized by the violin-
shaped marking on its back (Figure 2). This spider takes
rest during the day and is not aggressive but it will at-
tack in the case of provocation. Patients are usually bit-
ten by wearing clothes and shoes with spiders in them
Loxoscelism syndrome is the symptoms caused by the
bite of the brown recluse spider. This spider's bite is
usually painless but it later becomes an inflammatory,
hemorrhagic and painful lesion (8). Necrosis spreads a
few days following the bite and loxoscelism syndrome
results in dermatitis necrosis in the site of biting,
around which becomes red, white and blue, respective-
ly (9). The venom of this spider contains hyaluronidase
and sphingomyelinase D enzymes and results in necro-
sis. Moreover, neutrophil activity and platelet aggrega-
tion and thrombosis exacerbate necrosis (8). Local
manifestations of the bite of this spider include edema,
inflammation, hemorrhage, damage to the vessel wall,
thrombosis, and necrosis (10) but systematic symptoms
including acute renal failure, rhabdomyolysis and intra-
vascular hemolysis have also been reported (11). In
some cases, severe coagulopathy can result in stroke
(7).Considering extensive differential diagnosis for skin
necrosis, the standard criteria for the diagnosis of lox-
oscelism syndrome is capturing the spider during biting
or capturing it in the place where biting occurred and
its confirmation by a reliable arachnologist(12).
Dapsone, antihistamines, colchicine, corticosteroids and
hyperbaric oxygen have been used for treatment.
Treatment with dapsone can alleviate bite marks and
symptoms (8, 13). Antivenom reduces the size of the
necrotic area. The faster the antivenom is administered,
the less the manifestations. It has been proven useful
during the first 4 hours after the bite but according to
an investigation, it was useful even after 12 hours (14).
The bite-induced necrosis spreads in a few days and is
completed in a few weeks. Treatments include initial
debridement and in later stages, after improvement of
the inflammation, graft is used in case of severity (9).
b) Hobo spider
Hobo spider is a brown-colored spider with gray marks
along its body (Figure 3). The reason for its name is its
aggressive behavior following slight provocation. Symp-
toms induced by its bite are similar to those of the
brown recluse spider but necrosis is rare and perma-
nent scar is probable on the site of biting (12). The
cause of necrosis is the hemolytic property of the ven-
om or transmission of pathogenic bacteria inside the
site of biting (15). The systemic symptoms of biting are
reportedly cephalalgia and in some rare cases anaphy-
laxis and death. The treatment is similar to that of the
brown recluse spider. Moreover, resection should not
be conducted before the completion of the necrosis
process (8).
c) Black widow spider
Black widow spiders have a black hairless body. Males
are smaller than females. Its major characteristic is a
red marking on its abdomen similar to an hourglass
(Figure 4). It is not aggressive under normal circum-
stances but attacks if disturbed, especially while pro-
tecting its egg sacs. Moreover, it is the most important
venomous spider in North America and Australia (2, 3).
Its venom is alpha-latrotoxin (neurotoxic venom) which
results in the exocytosis of synaptic vesicles from para-
sympathetic terminals due to the stimulation of calci-
um-dependent mechanisms, releasing catecholamines
and acetylcholine (8).
The symptoms induced by the bite of this spider are
called latrodectism. The pain from its bite is similar to
that of a pinprick. A lesion similar to the target lesion
can be observed in the site of biting (16).Latrodectism
starts in a few minutes with the development of pain th-
Studies include in qualitative synthesis
Observational 10
Review 7
Book 2
Case report 2
Randomized clinical trial 1
Case series 1
Photo quiz 1
Guideline 1
Excluded by published in other
language (except English or Persian)
and/or full text review: 21 records
Excluded by abstract and/or full text
review: 211 records
Duplicate records: 6 records
Studies that we couldn’t access
abstract or full text of them: 9 records
Total search result:
272 records
Additional records identified in
Google Scholar: 2 records
Primary Search result:
270 records
Copyright © 2014 Shahid Beheshti University of Medical Sciences. All rights reserved.
Downloaded from:
Emergency (2014); 2 (2): 54-58
Figure 2: Brown Recluse Spider. Photograph by Richard
S.Vetter.Reproduced with permission
Figure 3: Eratigena-Agrestis (Hobo) Spider. Reproduced
with permission
Figure 4: Black Widow Spider (Photograph by Eric R.
Eaton. Reproduced with permission from
Figure 5: Phoneutria, commonly known as Brazilian wan-
dering spider or armed spider. Image
rough the whole body and symptoms such as emesis,
respiratory failure, delirium, partial paralysis of limbs,
abdominal muscle cramps, hypertension, pyrexia, fas-
ciculation and muscle spasm are developed within a
few hours (17). Symptoms may be mistaken with acute
abdomen. Mortality following biting is less than 1 %
and the risk of death following biting is high in two age
spectrums. Bites usually occur during warm months
(7). The chelicerae of this spider rarely leave a mark.
Following the bite, erythema, diaphoresis and piloerec-
tion are observed around the site of bite in 25 % of the
cases (3). Diagnosis is based on the patient's history.
While it can be difficult in children, hypertension, dis-
tress, diaphoresis and irritability can suggest diagnosis
in these cases (18).
The treatment of these patients consists of using muscle
relaxants, narcotics, analgesics, intravenous calcium
and antivenom. Narcotics and benzodiazepines relieve
muscle spasms. Antivenom treatment is recommended
for children, pregnant women the elderly and also pa-
tients with severe local symptoms, severe pains neces-
sitating repeated administration of narcotics and sys-
tematic symptoms (3). In the case of IV administration,
the antivenom should be diluted and injected slowly
(17). However, some centers have recommended IM
administration in order to reduce its complications. In
the case of IM administration, the effect is delayed and
symptoms take longer to improve (3) (within 1-5 days).
Some may suffer from chronic pains even after proper
antivenom treatment (18).
d) Armadeiras (armed spiders)
Armed spiders have long arms. Since they often hide in
banana boxes, they are known as banana bunch spiders
by locals (Figure 5).The symptom of its bite is severe
Copyright © 2014 Shahid Beheshti University of Medical Sciences. All rights reserved.
Downloaded from:
Rahmani et al
Figure 6:Funnel Web Spider (Reproduced with permission
Figure 7:Tarantula Spider (Mexican Red Legged Tarantu-
la) Photograph byRicBolzan. Reproduced with permission
pain which is observed in 96 % of patients (18). The
bite of this spider can cause respiratory failure and
death at both ends of the age spectrum (8). Its venom is
neurotoxic thus stimulates the autonomic nervous sys-
tem (tachycardia, hypertension, diaphoresis and saliva-
tion), priapism, dizziness and visual disturbances (19).
This venom is recommended to be used for controlling
permanent pathological pains due to its different com-
pounds and also its effect on pain neurons (20).
Patients receive supportive treatment including pain
and symptom control. There is antivenom for the
treatment of these patients but it is used in few cases
(21). With regard to the probability of respiratory fail-
ure in these patients, it is contradictory to use narcotics
for pain control. Therefore, local nerve block anesthesia
is recommended (8).
e) Funnel-web spider
Funnel-web spider, the most dangerous spider in the
world, is aggressive in the absence of provocation
(Figure 6) (3). The structure of this spider’s web is fun-
nel-shaped, hence the name (8).The venom of this spi-
der is neurotoxin and contains a large amount of pep-
tides (22, 23). Delta atracotoxin, one of the peptides in
the venom, delay the activation of voltage-dependent
sodium channels resulting in repeated stimulation and
release of massive neurotransmitters in nerve endings
(24). Robustoxin is another toxin in the venom of this
spider which is a fatal peptide and can be used for im-
munization (25).
Local symptoms include pain, diaphoresis, hives and
piloerection. Systemic symptoms include stimulation of
the parasympathetic system (nausea, emesis, salivation,
sialorrhea and tearing), cardiovascular system (hyper-
tension, mostly tachycardia and in some rare cases
bradycardia and hypotension), nervous system (fas-
ciculation and perioral paresthesia), non-cardiac pul-
monary edema (more prevalent in children), agitation,
and cephalalgia(3).
Treatment includes supportive measures, elastic band-
age for blocking lymph flow, limb immobilization and
rapid transportation to the hospital. Antivenom is the
definite cure and should be administered up to 15
minutes after opening the bandage. In the case of uncer-
tainty about the bite and exhibition of the first systemic
symptoms, 2 vials of antivenom are administered and in
the case of severe symptoms 4 vials are administered.
Other therapeutic measures include hemodynamic sup-
port, ventilatory support and the administration of tet-
anus vaccine. These measures reduce the risk of neuro-
logical complications and mortality and improve the
performance of patients after being discharged (7).
f) Tarantula
Tarantula is recognized by its hairy 3-inch brown or
black colored body (Figure 7). This type of spider is
kept as pet (8). Its venom is not dangerous for the hu-
man being and merely creates lesions without any spe-
cific systemic reaction except for pyrexia. Tarantula’s
defense mechanism is the hair on its body which stands
out and moves when alarmed (2). If these hairs enter
the eye, they can result in the inflammation of all of the
layers of the eye. Eye wash and topical corticosteroids
are recommended in the case of uveitis (8).
Recommendations for future
The human being has always been frightened of spiders
but few of them are venomous and thus real threat to
human health. However, since venomous spiders are
sometimes fatal, bites are recommended to be taken
care of. Moreover, it is recommended to be adequately
familiar with necessary treatments. With regard to the
identification of venomous spiders in our country in-
cluding widow spider which exists in the majority of
provinces, healthcare personnel must be familiar with
Copyright © 2014 Shahid Beheshti University of Medical Sciences. All rights reserved.
Downloaded from:
Emergency (2014); 2 (2): 54-58
the symptoms of the bites of venomous spiders and also
it is essential to prepare antivenoms in the country for
the treatment of spider bites. Finally, further domestic
investigations are necessary on the distribution of ven-
omous spiders and suspected cases of spider bite
should be reported to related centers to reduce the
damages caused by biting.
We acknowledge Managers of;www. aus-;; and ww
w.wikipedia.orgsites for let us to use their own images.
Conflict of interest:
Funding support:
Authors’ contributions:
All authors passed four criteria for authorship contribu-
tion based on recommendations of the International
Committee of Medical Journal Editors.
1. Hickman C, Roberts L, Keen S, Larson A, I’Anson H, Eisenh-
our D. Integrated principles of zoology. 14 ed. China: McGraw-
Hill; 2008. p. 402-12.
2. Diaz JH, Leblanc KE. Common spider bites. Am Fam
Physician. 2007;75(6):869-73.
3. Braitberg G, Segal L. Spider bites: assessment and manage-
ment. Aust Fam Physician. 2009;38(11):862-7.
4. Rajendra W, Armugam A, Jeyaseelan K. Toxins in anti-noci-
ception and anti-inflammation. Toxicon. 2004;44(1):1-17.
5. Ahmed KZ, Bushra R. Antivenom therapy of spider bite en-
venomation. Pak J Pharmacol. 2008;25(2):39-45.
6. Vetter RS, Isbister GK. Medical aspects of spider bites. Annu
Rev Entomol. 2008;53:409-29.
7. Garcia H, Tanowitz H, Del Brutto O. Neurological effects of
venomous bites and stings: snakes, spiders, and scorpions.
Neuroparasitology and Tropical Neurology: Handbook of Clin-
ical Neurology Series (Editors: Aminoff, Boller, Swaab).
8. Tintinalli JE, Stapczynski JS, Ma OJ, Cline D, Cydulka R,
Meckler G. Tintinalli's emergency medicine: a comprehensive
study guide: McGraw-Hill Medical; 2011. p. 1344-54.
9. Garza Ocañas L, Mifuji RM. Cutaneous Loxoscelism. N Engl J
Med. 2013;369(5):495-500.
10. Isbister GK, Fan HW. Spider bite. The Lancet.
11. Malaque C, Santoro ML, Cardoso JLC, et al. Clinical picture
and laboratorial evaluation in human loxoscelism. Toxicon.
12. Bennett RG, Vetter RS. An approach to spider bites.
Erroneous attribution of dermonecrotic lesions to brown
recluse or hobo spider bites in Canada. Can Fam Physician.
13. Bogdán S, Barabás J, Zacher G, et al. Total upper lip
necrosis and loxoscelism caused by violin spider bite. Orv
Hetil. 2005;146(45):2317-21.
14. Pauli I, Minozzo JC, Henrique da Silva P, Chaim OM, Veiga
SS. Analysis of therapeutic benefits of antivenin at different
time intervals after experimental envenomation in rabbits by
venom of the brown spider (Loxosceles intermedia). Toxicon.
15. Gaver-Wainwright MM, Zack RS, Foradori MJ, Lavine LC.
Misdiagnosis of spider bites: bacterial associates, mechanical
pathogen transfer, and hemolytic potential of venom from the
hobo spider, Tegenaria agrestis (Araneae: Agelenidae). J Med
Entomol. 2011;48(2):382-8.
16. Shlamovitz GZ. Man With Back Pain. Ann Emerg Med.
17. Nordt SP, Clark RF, Lee A, Berk K, Lee Cantrell F. Examin-
ation of adverse events following black widow antivenom use
in california. Clin Toxicol. 2012;50(1):70-3.
18. Monte AA, Bucher-Bartelson B, Heard KJ. A US perspective
of symptomatic Latrodectus spp. envenomation and treatm-
ent: a national poison data system review. Ann Pharmacother.
19. Gewehr C, Oliveira SM, Rossato MF, et al. Mechanisms
involved in the nociception triggered by the venom of the
armed spider phoneutria nigriventer. PLoS Negl Trop Dis.
20. Souza AH, Ferreira J, Cordeiro Mdo N, et al. Analgesic
effect in rodents of native and recombinant Ph alpha 1beta
toxin, a high-voltage-activated calcium channel blocker isolat-
ed from armed spider venom. Pain. 2008;140(1):115-26.
21. Isbister GK, Graudins A, White J, Warrell D. Antivenom
treatment in arachnidism: antivenoms. Clin Toxicol.
22. Liu J, Gao J, Yun Y, Hu Z, Peng Y. Bioaccumulation of mer-
cury and its effects on survival, development and web-
weaving in the Funnel-Web spider agelena labyrinthica (Aran-
eae: Agelenidae). Bull Environ Contam Toxicol.
23. Palagi A, Koh J, Leblanc M, et al. Unravelling the complex
venom landscapes of lethal Australian funnel-web spiders
(Hexathelidae: Atracinae) using LC-MALDI-TOF mass spectr-
ometry. J Proteomics. 2013;80:292-310.
24. Pineda SS, Wilson D, Mattick JS, King GF. The lethal toxin
from Australian funnel-web spiders is encoded by an intronl-
ess gene. PLoS One. 2012;7(8):e43699.
25. Comis A, Tyler M, Mylecharane E, Spence I, Howden M.
Immunization with a synthetic robustoxin derivative lacking
disulphide bridges protects against a potentially lethal chall-
enge with funnel-web spider (Atrax robustus) venom. J Biosci.
... (5,7) In this regard, all spider bites have a variety of signs and symptoms that can be divided into local and systemic. (5,7,8) In cases of latrodectism and steatodism, the clinical manifestations are similar (Table 1), although the latter is usually less severe. (7,9) Local manifestations include pain, pruritus, edema and erythema, whereas systemic symptoms can include abdominal or thoracic pain, nausea, diaphoresis, malaise, fever and headache. ...
... (7,9) Local manifestations include pain, pruritus, edema and erythema, whereas systemic symptoms can include abdominal or thoracic pain, nausea, diaphoresis, malaise, fever and headache. (5,7,8) Other species of spiders can cause blisters, ulcers, necrosis and more severe organ involvement (for example Loxosceles spp.). (5,7,8) Source: Own elaboration based on (10), (11), (12), (13), (14), (15) and (16). ...
... (5,7,8) Other species of spiders can cause blisters, ulcers, necrosis and more severe organ involvement (for example Loxosceles spp.). (5,7,8) Source: Own elaboration based on (10), (11), (12), (13), (14), (15) and (16). ...
Full-text available
Introduction: Accidents involving spiders bites usually cause mild medical reactions that lead to local symptoms and, less commonly, systemic effects. The most medically significant spiders belong to the genera Latrodectus and Loxosceles. This paper presents a possible case of steatodism in a young woman and her pet. Case description: 26-year-old female patient, who reports a clinical history characterized by paresthesia, malaise, fever, diarrhea and a painful papule in the left cheek after being bitten by a spider. Immediately after being bit, the patient hit the spider with the back of her hand and it fell to the ground, where her dog swallowed it. The dog presented with vomiting and general discomfort after ingestion. Symptomatic therapy was given for comfort, and neither the patient nor the dog required antivenin therapy. Both evolved favorably. Discussion: The relevance of this case is the involvement of two mammals (a human and her dog) due to the accidental contact with a spider, possibly of the genus Latrodectus or Steatoda. Conclusion: Two possible cases of steatodism are described. Since spider bites are a relatively frequent reason for medical consultation in Colombia, it is important to diagnose and manage them properly.
... Although more than 40,000 species of spiders have been identified all over the world, only a few are venomous 1 . Spiders belong to the class Arachnida in the phylum Arthropoda. ...
... Spiders belong to the class Arachnida in the phylum Arthropoda. Except for a few groups in the arachnid family, all others have venom glands, but a majority do not bite, because most spider fangs are too small to penetrate human skin 1 ...
Full-text available
Spiders belong to the class Arachnida in the phylum Arthropoda. Although the bite of the spider is feared as much as that of venomous snakes in Sri Lanka, spider bite related deaths are not reported in this country. A 43-year-old patient presented with local swelling, pain, bleeding from puncture site and muscle cramps after a Poecilotheria subfusca (Ivory-billed ornamental or montane tiger spider) bite; and a 45-year-old patient presented with numbness, burning pain and muscle cramps after a Poecilotheria fasciata (Ceylon Hunting Spider/Ornamental Tarantula) bite. Both patients recovered completely without residual effects.
... A bite is often painful, and is followed by redness, swelling and discomfort which can last for a few hours or more before it subsides (Fig. 9). In humans, anaphylaxis or an allergic reaction caused by a tarantula bite is extremely rare (Ahmed et al., 2009;Hauke & Herzig, 2017;Matabuey, 2016;Rahmani et al., 2014). Tarantula bites should be cleaned with antiseptic to reduce the transference of any pathogens, such as Staphylococcus aureus. ...
Technical Report
Full-text available
The purpose of this guide is to assist enforcement officers by providing the information required to identify specimens of tarantula species that are listed in the Appendices of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). The identifying characters of one species of Aphonopelma, 16 species of Brachypelma, and two species of Sericopelma are described in text and accompanying photographs. Collectively, these species comprise all of the tarantula species that are listed on the Appendices of CITES (at the time of writing). Common names, scientific synonyms and distribution summaries are also provided. In addition, information is provided on basic tarantula morphology, and anticipated changes to Brachypelma taxonomy is discussed. Safe handling techniques are also reviewed for officers who may be required to inspect shipments of tarantulas, or otherwise interact with live specimens.
... Latrodectism is a condition that results from envenoming by species belonging to the genus Latrodectus (Araneae: Theridiidae) [1]. It is associated with dramatic discharge of neurotransmitter, particularly in the autonomic system [2]. ...
Full-text available
Te frst case of envenoming by Latrodectus geometricus in Egypt is described. Te accident occurred at the victim’s home, in Tookh El-Kheil, Minia governorate. Te 29-year-old female victim was bitten on the right forearm. She developed a hyperactive state of the central, autonomic and peripheral nervous systems, respiratory distress, severe abdominal colic with minor local symptoms. Later on, the patient developed paralytic ileus. Unfortunately, due to the lack of the antivenin in Egypt, the patient was treated symptomatically. By the 5th day, she was completely clinically free and discharged the next day.
Background Rhabdomyolysis after spider bite has been reported in a small number of patients, and myocarditis in even fewer. However, arrhythmia associated with latrodectism in children has not been described in the literature to date. Case summary A girl presented approximately 4.5 h after being bitten on the left ankle by a black spider. Two unifocal premature ventricular contractions (PVCs) were observed on the electrocardiogram. In laboratory tests, creatine kinase was elevated. On day 2, levels of troponin, pro-brain and natriuretic peptide were elevated. Electrocardiogram revealed inverted and biphasic T waves. Echocardiography revealed mild left ventricular dilation, mitral and aortic valve regurgitation. Holter electrocardiogram showed PVCs. Her laboratory and echocardiography findings completely normalized after discharge, and no arrhythmia was observed on the Holter electrocardiogram during outpatient follow-up. Conclusion Although spider bites are uncommon, they can cause serious systemic effects. These patients should be evaluated for arrhythmia, rhabdomyolysis and myocarditis.
Envenomation is the exposure to a poison or toxin resulting from a bite or sting from an animal. The medically important venomous animals consist of snakes, spiders, scorpions, hymenoptera (bees, wasps, and ants), and marine animals (fish and cnidarians, such as jellyfish, anemones, and corals). There is a lack of information about envenomations in pregnancy, its treatment, and effects. Symptoms from an envenomation produce characteristic reactions depending on the animal involved, which may be the same or may be more pronounced during pregnancy due to physiologic maternal changes. Pharmacologic therapy is directed at symptomatic and supportive care, and specific therapy if available. Decisions to use a specific antidotal therapy (antivenom) must take into account the potential for allergic reactions, either Type 1 (anaphylaxis) or Type 3 (serum sickness) and the risk–benefit assessment in pregnancy includes the potential for adverse effects on the fetus. Antivenoms, currently available for some snakes, spiders, and scorpions, are generally indicated when there is (1) evidence of systemic envenomation or (2) severe local envenomation effects. Consultation with a poison center and its medical toxicologist is recommended when treating pregnant patients. Concerns about pregnancy and pregnancy-related risks may prompt providers to observe envenomated patients longer or to admit them to the hospital for monitoring or additional treatment. Little data exist, and in the United States, there are few reports of adverse pregnancy outcomes with envenomations. Regardless, before discharge from a health facility, patients should be coherent, tolerate oral intake, have no progression of symptoms, and any pain should be adequately controlled with oral analgesics. More long-term evaluations of individual cases are encouraged to better characterize the results of specific envenomations in pregnancy and determine additional strategies other than standard therapies.
Visual hallucinations (VHs) are extremely rare in snakebites. We report a case of Russell’s viper bite in an otherwise healthy 55-y-old woman who presented to a hospital in south India with established clinical features of systemic and local envenomation, including coagulation failure, without any neurologic manifestations on admission. She reported simple VH on the third day, which abruptly stopped on the fifth day without any specific medications. Clinical, laboratory, imaging, and electrophysiological studies did not reveal any neuropsychiatric disorders. Including this case, only 5 cases of VH are documented in the literature, 2 following cobra and viper bites and 1 after a sea snake bite. Two cases were reported from Australia and 1 each from the United States, Iran, and India.
Full-text available
Bed bug infestation rate has gone through an unforeseen increase in the past decades worldwide. Their resurgence is a consequence of numerous factors, including growing population density, increased international travel and the spread of insecticide resistance. Bed bug infestation is often revealed by skin symptoms appearing after their bite in sensitive patients. Medical professionals encountering patients with bed bug bites have responsibility for recognizing the condition and for instructing patients about the necessary measures for eradication. Setting the correct diagnosis, however, is not unequivocal as several skin diseases with autoimmune, immune-mediated aetiology or other arthropod stings and bites may present with similar symptoms. In this review we provide a differential diagnostic guide and an atlas of clinical pictures assigned to the diagnoses. We highlight those dermatological findings where the possibility of bed bug bite arises and identify key elements that help in the differentiation so as to avoid unnecessary diagnostic tests and force early start of extermination.
Exposure to a wide range of toxic agents that induce nephrotoxicity is a public health problem, specifically in developing countries. The interactions and mechanisms between these substances and the body could produce relevant disorders such as toxic acute kidney injury (AKI). Ingestion or inhalation of nephrotoxic substances is the primary way of community-acquired AKI. Poisoning by plants, animals, medications, chemicals, and illicit drugs induces AKI and has different mechanisms of nephrotoxicity. The recognition of toxic mechanisms in different acute poisonings and envenomation is crucial to plan effective treatment. In this chapter, we focus on the most relevant causes of toxic-AKI due to drugs, self-poisoning with pesticides, toxic plants, chemicals such as laundry detergents, herbal medicines, and snakebite envenomation, and the use of extracorporeal therapies for some toxic agents.
Black widow spiders are found across the United States and worldwide. Building webs in uninhabited dark places such as barns, garages, fences, and woodpiles, these spiders only bite when unexpectedly disturbed. Black widow spider bites cause local pain with minimal swelling, and may present with greater systemic severity, including autonomic dysfunction and abdominal rigidity. The prognosis is good, and mortality is rare. Treatment is generally supportive and focuses on pain control, but the clinical presentation warrants ruling out other concerning diagnoses.
Full-text available
Background The frequency of accidental spider bites in Brazil is growing, and poisoning due to bites from the spider genus Phoneutria nigriventer is the second most frequent source of such accidents. Intense local pain is the major symptom reported after bites of P. nigriventer, although the mechanisms involved are still poorly understood. Therefore, the aim of this study was to identify the mechanisms involved in nociception triggered by the venom of Phoneutria nigriventer (PNV). Methodology/Principal Findings Twenty microliters of PNV or PBS was injected into the mouse paw (intraplantar, The time spent licking the injected paw was considered indicative of the level of nociception. injection of PNV produced spontaneous nociception, which was reduced by arachnid antivenin (ArAv), local anaesthetics, opioids, acetaminophen and dipyrone, but not indomethacin. Boiling or dialysing the venom reduced the nociception induced by the venom. PNV-induced nociception is not dependent on glutamate or histamine receptors or on mast cell degranulation, but it is mediated by the stimulation of sensory fibres that contain serotonin 4 (5-HT4) and vanilloid receptors (TRPV1). We detected a kallikrein-like kinin-generating enzyme activity in tissue treated with PNV, which also contributes to nociception. Inhibition of enzymatic activity or administration of a receptor antagonist for kinin B2 was able to inhibit the nociception induced by PNV. PNV nociception was also reduced by the blockade of tetrodotoxin-sensitive Na+ channels, acid-sensitive ion channels (ASIC) and TRPV1 receptors. Conclusion/Significance Results suggest that both low- and high-molecular-weight toxins of PNV produce spontaneous nociception through direct or indirect action of kinin B2, TRPV1, 5-HT4 or ASIC receptors and voltage-dependent sodium channels present in sensory neurons but not in mast cells. Understanding the mechanisms involved in nociception caused by PNV are of interest not only for better treating poisoning by P. nigriventer but also appreciating the diversity of targets triggered by PNV toxins.
Full-text available
This study investigated the bioaccumulation and effects of mercury (Hg) in funnel-web spiders, Agelena labyrinthica, following exposure to sublethal concentrations of Hg(NO(3))(2) in their drinking water. The results showed that the Hg content in adult A. labyrinthica increased rapidly with the number of days exposed to the Hg(NO(3))(2) solution, and the mortality of adult spiders within 30 days increased with increased concentrations of Hg(NO(3))(2) in the drinking water. The total developmental duration of A. labyrinthica exposed to Hg(NO(3))(2) was significantly longer than in the control spiders, but there were no significant differences in the total developmental duration of spiders among the three treatment groups (exposed to 10, 20 and 50 mg/L Hg(NO(3))(2) solution). We also compared the web-weaving of the control and treated spiders, and found no significant differences in shape, structure, color, or size of the webs between the control and treated spiders; however, there was a significant difference in web placement between the treatment and control groups. The spiders in the control group appeared to have an episodic-like memory, choosing to weave their five webs in the same corner in the five time periods allowed.
Full-text available
Australian funnel-web spiders are generally considered the most dangerous spiders in the world, with envenomations from the Sydney funnel-web spider Atrax robustus resulting in at least 14 human fatalities prior to the introduction of an effective anti-venom in 1980. The clinical envenomation syndrome resulting from bites by Australian funnel-web spiders is due to a single 42-residue peptide known as δ-hexatoxin. This peptide delays the inactivation of voltage-gated sodium channels, which results in spontaneous repetitive firing and prolongation of action potentials, thereby causing massive neurotransmitter release from both somatic and autonomic nerve endings. Here we show that δ-hexatoxin from the Australian funnel-web spider Hadronyche versuta is produced from an intronless gene that encodes a prepropeptide that is post-translationally processed to yield the mature toxin. A limited sampling of genes encoding unrelated venom peptides from this spider indicated that they are all intronless. Thus, in distinct contrast to cone snails and scorpions, whose toxin genes contain introns, spiders may have developed a quite different genetic strategy for evolving their venom peptidome.
Full-text available
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. Treatment has ranged from symptomatic care to administration of specific antivenom. Declining antivenom availability and, possibly, the fear of hypersensitivity allergic reactions, has limited antivenom use in the US. To describe Latrodectus spp. exposures and the subsequent treatment reported to US poison centers; the secondary objective was to identify factors associated with shorter duration of symptoms (<24 hours). All Latrodectus spp. exposures reported to the National Poison Data System (NPDS) between January 1, 2000, and December 31, 2008, were reviewed. Cases with at least minor clinical effects due to Latrodectus spp. exposure were extracted. Descriptive statistics were generated. The probability that symptom duration was less than 24 hours was modeled, using logistic regression. From 2000 through 2008, a total of 23,409 Latrodectus spp. exposures were reported in 47 states; 9872 cases had at least minor clinical effects and were included in the subsequent analysis. Exposures peaked in September and fell to a nadir in January and February. Fifty-eight percent of the cases involved males, and the mean (SD) age was 31.5 (17.4) years. Sixty-five percent of the patients had minor clinical effects, 33.5% had moderate effects, 1.4% had major effects, and there were no deaths. Antivenom use was associated with symptom duration of less than 24 hours in moderate and major outcome groups. There was no evidence of shorter symptom duration in patients who received benzodiazepines or calcium. Adverse drug reactions were more common in patients receiving benzodiazepines and antivenom. In the US, most symptomatic Latrodectus spp. exposures reported to the NPDS are minor. Few patients receive antivenom, although antivenom is associated with shorter symptom duration among moderate and major outcomes.
Snake and spider bites, as well as scorpion sting envenoming, are neglected diseases affecting millions of people all over the world. Neurological complications vary according to the offending animal, and are often directly related to toxic effects of the venom, affecting the central nervous system, the neuromuscular transmission, the cardiovascular system, or the coagulation cascade. Snake bite envenoming may result in stroke or muscle paralysis. Metalloproteinases and other substances (common in vipers and colubrids) have anticoagulant or procoagulant activity, and may induce ischemic or hemorrhagic strokes. The venom of elapids is rich in neurotoxins affecting the neuromuscular transmission at either presynaptic or postsynaptic levels. The clinical picture of scorpion sting envenoming is dominated by muscle weakness associated with arterial hypertension, cardiac arrythmias, myocarditis, or pulmonary edema. These manifestations occur as the result of release of catecholamines into the bloodstream or due to direct cardiac toxicity of the venom. Cerebrovascular complications have been reported after the sting of the Indian red scorpion. Intracranial hemorrhages occur in the setting of acute increases in arterial blood pressure related to sympathetic overstimulation, and cerebral infarctions are related to either cerebral hypoperfusion, consumption coagulopathy, vasculitis, or cardiogenic brain embolism. Three main syndromes result from spider bite envenoming: latrodectism, loxoscelism, and funnel-web spider envenoming. Latrodectism is related to neurotoxins present in the venom of widow spiders. Most cases present with headache, lethargy, irritability, myalgia, tremor, fasciculation, or ataxia. Loxoscelism is caused by envenoming by spiders of the family Sicariidae. It may present with a stroke due to a severe coagulopathy. The venom of funnel-web spiders also has neurotoxins that stimulate neurotransmitter release, resulting in sensory disturbances and muscle paralysis. Proper management of the envenomed patient, including prompt transport to the hospital, correction of the hemostatic disorder, ventilatory support, and administration of antivenom, significantly reduce the risk of neurological complications which, in turn, reduce the mortality and improve the functional outcome of survivors.
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. We performed the current study to determine rate of adverse effects and the efficacy of AV in patients treated for widow spider envenomation. Observational case series of the California Poison Control System electronic database from January 1999 to December 2009. All cases of widow spider envenomation treated with AV were included. Age, gender, signs, and symptoms, adjunctive therapy, number of vials of AV given, and adverse reaction to AV were recorded. Descriptive statistical methods were used. Ninety-six patients received AV, mean age 26 years (0.12-74 years), 76% male. Following widow spider envenomation generalized pain was reported in 91%, erythema at site in 57%, hypertension (≥ 140/90 mmHg) in 43%, muscle rigidity/cramping in 43%, abdominal pain in 41%, tachycardia (≥ 100 bpm) in 23% and diaphoresis in 21%. No patient required more than one vial of AV. One patient developed urticaria to AV halfway through infusion which was immediately discontinued. Another patient developed generalized flushing following completion of infusion but had no other effects. Two other patients reported myalgia and paresthesia. There were no deaths in any patients receiving AV. There was no shortness of breath or respiratory distress, no hypotension or chest pain following AV administration. All patients reported pain relief with AV and did not require additional AV doses. Our results suggest that Black Widow Spider Antivenin® (Merck) administration is relatively safe with mild to moderate adverse effects seen in only a small percentage of patients. There were no deaths, or severe allergic reactions identified. The retrospective use of poison control system data is a limitation of our study. Further prospective studies are needed to validate our findings and elucidate the full safety profile on this antivenom.