Arachnid Envenomation in Taiwan

Arachnid Envenomation in Taiwan S12Arachnid Envenomation in TaiwanShih-Wen Hung, MD; Tzong-Luen Wang, MD, PhDAbstractTaiwan is located at the juncture of tropical and subtropical regions. About 300 species of spidersin Taiwan are named. Among the variety of spiders, only two kinds of spiders are reported to doserious harm to people. They are Latrodectus hasselti (red back spider) and Macrothele species(include M. gigas, M. holsti and M. taiwanensis). Tarantula which is mainly imported for pettingwould also do harm to people. Until now, no mortality case after spider bite was reported inTaiwan. The treatments of spider bite in Taiwan are supportive treatments. It is important to educatepeople not to capture the spiders with hands and be aware of the spiders especially in the darkand wet environment. If bitten by a spider, it is important to search medical support as soon aspossible.(Ann Disaster Med. 2004;3 Suppl 1:S12-S17)Key words: Arachnid Envenomation; Taiwan; Disaster MedicineIntroductionMore than 35,000 species of spiders are namedthroughout the world and hundreds more thanthat have not yet been identified. Spiders arenotorious for the venomous bite especially thewell-known “black widow spider”. Manypeople over the world have the symptom of“arachnophobia”, which means the fear of thespiders. It is true that almost all spiders are venomousto their prey. However, most spidersare not harmful to people. Actually, there areonly 20 to 30 spiders over the world have thepossibility to cause serious damage to us. Mostspider bite would only cause itching anderythematous change and will recover spontaneouslyin 1 to 3 days. 1,2,3,4Taiwan is located at the juncture of tropicaland subtropical regions. It has a warm and humidclimate with abundant precipitation andfood, which coupled with the island’s diversevegetation and landscape, make it a suitable environmentfor many spider species. About 300species of spiders in Taiwan are named and almost3 to 4 times are not yet named. Amongthe variety of spiders, only two kinds of spidersare reported to do serious harm to people.They are Latrodectus hasselti (redback spider)and Macrothele species (include M. gigas, M.holsti and M. taiwanensis). Beside this two speciesof venomous spiders, there are also someimported venomous spiders which are feed aspets. The Tarantula is the most famous one. Untilnow, no mortality case after spider bite wasreported in Taiwan. 1,4 We will introduce theseFrom Department of Emergency Medicine, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, TaiwanAddress for reprints: Dr. Tzong-Luen Wang, Department of Emergency Medicine, Shin Kong Wu Ho-Su Memorial Hospital,No 95, Wen Chang Road, Taipei, TaiwanReceived: Sep 8 2004. Revised: Sep 28 2004. Accepted: Oct 3 2004.TEL: 886-2-28389425 FAX: 886-2-28353547 E-mail: M002183@ms.skh.org.twAnn Disaster Med Vol 3 Suppl 1 2004

Arachnid Envenomation in Taiwan S14mitter substance. It increases in frequency ofminiature endplate potentials at the neuromuscularjunctions and causes the depletion of acetylcholineand patchy paralysis of voluntarymuscle. It also causes release of othertransmitters, like catecholamines, and inducesstructural changes to sensory nerve terminals,similar to those occurring at motor endplates.Some study in mice showed that the toxin wouldrapidly disrupt Schwann cells. However, after48 hours, reinnervation would occur and becomecomplete normality in 8 days. 5,15,16Macrothele sp.The venoms of Macrothele are not wellcharacterized. But the toxins of their relatives,Sydney funnel web and Hadronyche versuta,were confirmed. The toxins of these two kindsof spiders are robustotoxin and versutoxin. Bothtoxins consist of 42 amino acid residues andthe clinical effects are similar. 9 The toxins areproteins that will bind to autonomic and motorneurons. Not only cause neurotransmittersrelease, they will inhibit neurologically mediatedneurotransmitter release. If the peripheral nervoussystems are involved, they will cause skeletalmuscle spasm, fasciculations and patchyweakness. Autonomic stimulation causes excessivesecretions, piloerection, tachycardia, hypertensionand cardiac arrhythmias. Hypotensionmay occur after hypertension due to catecholaminedepletion and/or impaired catecholaminerelease. After subcutaneousinjection, the venom will reach the circulationrapidly (approximately 2 minutes). 9,17TarantulaThe venom of tarantula is rarely toxic to humans.It usually cause painful sensation and is notdangerous. The typical effects are no more serousthan those of hymenopteran stings. Themost common reaction is a low-grade histamineresponse. Tarantula can also attack peopleby their hairs. The hairs discharged from theTarantula can penetrate several layers of skinor ocular tissue and cause mechanical irritation.Inhalation of urticating hairs may cause significantallergic rhinitis. Small mammals may suffocatewithin 2 hours if they exposure to someTaratula hairs. 9,17SymptomatologyRedback spiderSerious complications are seldom occurredwithin 3 hours after biting. The most bites areoccurred to the distal parts of the limbs. 5 Thebites may initially be unnoticed but the mostcommon effect of envenomation is still the intenselocal pain. The site may become hot,warm, red and swelling. If systemic envenomationoccurred, patient could have the symptomsof nausea, vomiting, generalized sweating,paraesthesias, mild pyrexia, insomnia, dizziness,headache and hypertension. Some uncommonsymptoms and signs have been reported, includingtitanic spasms, trismus, tingling teeth,swollen tongue, bite site infection, convulsions,thirst, diarrhea, anaphylaxis, blotchy rashes,patchy sweating, hemoptysis, dyspnea, dysuria,persistent anorexia, priapism, albuminuria,leukocytosis, periorbital edema andconjunctivitis. 5,15,16Macrothele sp.Because the fangs of the spider are large andenter with considerable force, the bite is verypainful and the pain will persist for hours to days.Perioral tingling usually occurs within 15 min-Ann Disaster Med Vol 3 Suppl 1 2004

S15 Arachnid Envenomation in Taiwanutes followed by tongue spasms, lacrimation,salivation, abdominal pain, nausea, vomiting,diaphoresis or severe dyspnea. Muscle fasciculationsand spasms are also common. Cardiacarrythmias and cardiac arrest may occur. Severepulmonary edema may occurs early andbe fatal. 9,17TaruntulaMild pain similar to a pinprick is the most complaintof Taruntula bite. However, some bitesmay cause severe pain, local swelling andnumbness. If the bite is near the joint, arthriticstiffness may last for several weeks. 12 Ocularexposure to tarantula hairs may lead to ocularinjury and the patient may have a red eye andassociated keratoconjunctivitis. Significant allergicrhinitis may be present in patients whohave inhaled hairs. Anaphylaxis is a rare complicationof Taruntula hair exposure. 12,18TreatmentRedback spiderDuring prehospital period, pressure-immobilizationbandaging is not recommended becausethe progression of envenomation is usually slow.Ice packing is an effective analgesic. Supportivetreatment with ACLS protocols is required.Tetenus prophylaxis should be done. The goalof therapy is to neutralize the toxin of the spiderbite with the antivenom. However, there is noantivenom available in Taiwan. Fortunately, theoutcome of Latrodectus species bite, even themost venomous black widow spider, is good.Most patients do not need hospitalization andneed only supportive treatments. The supportivetreatments focus on alleviating pain andmuscle cramping. The three main treatments arepain relievers such as narcotics, musclerelaxants, and intravenous calcium gluconate.The effect of calcium gluconate is not clear butit seems to reduce the mortality and morbidity.The dose of calcium gluconate is 1-2ml/Kg with10% solution as slowly intravenous route, notexceed 10 ml/dose. Antihistamine may be prescribedfor skin itching and antibiotics are nothelpful. Most patients will recover fully. 5,15,16,19Macrothele sp.The prehospital care is mainly supportive treatmentswith ACLS protocols. Most bites do notresult in envenomation and pain is the most commoncomplaint. When envenomation occurs,standard life support measures and antivenintherapy are necessary. However, there is noantivenum available in Taiwan and supportivetreatment is the main way. Tetanus immunizationmust be prescribed. Victims may be dischargedsafely in one day or so if they responsewell to antivenin. If antivenum is unavailable,the patient may need to stay more days in intensivecare unit. Hypertension may be treatedwith alpha-blocker. Ventilator is indicated if respiratoryfailure is noted. 9,17,19,20TarantulaSupportive care is needed in prehospital stage.Eye protective shield may be needed followingocular exposure to prevent the patient from rubbingthe eyes and driving the hairs deeper. Inhospital, it is most important to relieve thesymptoms. Antihistamine and analgesics may beused to relieve itching sensation and pain. Tetanusimmunization is indicated. The ophthalmologistshould be consulted for orbital involvementsand topical broad-spectrum antibiotic may behelpful. Following up in ophthalmologist departmentis recommended. If anaphylaxis occurs,Ann Disaster Med Vol 3 Suppl 1 2004

Arachnid Envenomation in Taiwan S16admission is indicated. Chronic local dermatitiscaused by urticating hair could be controlledby oral steroid and antihistamine. 12,18,22,23Education, prevention and supportive care arethe main management strategies for such kindof animal injury.Case report in Taiwan 4There is only one case report about spider envenomationin Taiwan. In May 2000, a fouryear-oldboy was bitten over left middle toe bya hidden spider in his shoes when he was wearingthem. About 10 minutes later, severe painover left foot and muscle cramping over leftlower leg with mild claudication were noted.There was an obvious red line extended fromthe wound to inguinal area and abdominal painwas also noted. Two hours later, generalweakness, poor appetite, drowsiness, drooling,vomiting and chills happened. He was sent toemergency department ten hours later. Physicalexamination showed tachycardia ,a targetlesion over left middle toe and rigidity over leftlower leg. Bilateral inguinal lymph nodes enlargementand mild abdominal tenderness werenoted. Lab data showed leukocytosis and mildhypoglycemia. 10% Calcium gluconate, glucose-containingfluid, antihistamine and prophylacticantibiotics were prescribed. Patient wasdischarged under stable condition 48 hours later.The spider was finally confirmed as Macrothelesp.ConclusionOf 300 species in Taiwan, only two kinds ofspiders are reported to do serious harm topeople. They are Latrodectus hasselti (redback spider) and Macrothele species (includeM. gigas, M. holsti and M. taiwanensis). Tarantulawhich is mainly imported for pettingwould have the same effects. There is still nomortality case after spider bite in Taiwan.References1. Chen SH. A guide to common spiders ofTaiwan:64-672. Allen C. Arachnid envenomations. EmergMed Clin North Am 1992;10:269-983. Saucier JR. Arachnid envenomation. EmergMed Clin North Am 2004;22:405-224.Medical digest 2000;31:244-495. Hampton Roy, Sr, MD. spider bites. Availableat: URL: http://www.emedicine.comassessed at June 6 th , 20046. Wilson DC, King LE. Spiders and spiderbites. Dermatol Clin 1990;8:277-867. Simon GA Brown, MD. SpiderEnvenomations, Redback. Available at:URL:http://www.emedicine.com assessedat June 6 th , 20048. Jelinek GA, Banham ND, Dunjey SJ. Redbackspider-bites at Fremantle Hospital,1982-1987. Med J Aust 1989;150:693-59. Simon GA Brown, MD: SpiderEnvenomations, Funnel Web. Available at:URL:http://www.emedicine.com assessedat June 6 th , 200410. Dieckmann J, Prebble J, McDonogh A, etal. Efficacy of funnel-web spider antivenomin human envenomation by Hadronychespecies. Med J Aust 1989;151:706-711.2003:239-4112.Fell SD, Kukula CL. SpiderEnvenomations, Tarantula. URL:http://www.emedicine.comAnn Disaster Med Vol 3 Suppl 1 2004