Spiders & their toxins
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Transcript of Spiders & their toxins
Spiders & their toxinsSpiders & their toxins
Joe Alcock MD MS
Emergency Medicine, NM VAMC
UNM Dept Emergency Medicine
Joe Alcock MD MS
Emergency Medicine, NM VAMC
UNM Dept Emergency Medicine
21 year old woman in Sydney21 year old woman in Sydney
Cleaning out swimming pool trap Feels a sharp pain in her right hand Develops nausea, paresthesias, sweats
Cleaning out swimming pool trap Feels a sharp pain in her right hand Develops nausea, paresthesias, sweats
Sydney Funnel Web SpiderSydney Funnel Web Spider
Funnel Web SpiderFunnel Web Spider
Australasian funnel-web spiders
Suborder Mygalomorphae - includes tarantulas
Family Hexathelidae Sydney f.w.s Atrax
robustus Chelicerae (fangs)
contain venom apparatus 2 genera in Australia:
Atrax, Hadronyche
Australasian funnel-web spiders
Suborder Mygalomorphae - includes tarantulas
Family Hexathelidae Sydney f.w.s Atrax
robustus Chelicerae (fangs)
contain venom apparatus 2 genera in Australia:
Atrax, Hadronyche
Range & habitatRange & habitat
Eastern coast of Australia
Fws also found in New Guinea & Solomon Islands
Spiders construct a funnel shaped web and wait for prey to fall in.
Funnels constructed near rocks, logs
Diet consists of insects and small vertebrates
Eastern coast of Australia
Fws also found in New Guinea & Solomon Islands
Spiders construct a funnel shaped web and wait for prey to fall in.
Funnels constructed near rocks, logs
Diet consists of insects and small vertebrates
Scope of problemScope of problem
77 severe envenomations between 1999 and 2003
Deaths only recorded from Atrax robustus
No deaths since introduction of antivenom
77 severe envenomations between 1999 and 2003
Deaths only recorded from Atrax robustus
No deaths since introduction of antivenom
ToxicityToxicity 77 severe cases 1999 - 2003 Male spiders cause most bites 10-25% bites produce toxicity Spiders measure 5 cm, fangs can penetrate
fingernails Delta-Atracotoxins Presynaptic neurotoxins - open sodium
channels - inducing action potentials Autonomic storm - endogenous Ach
norepinephrine & epinephrine.
77 severe cases 1999 - 2003 Male spiders cause most bites 10-25% bites produce toxicity Spiders measure 5 cm, fangs can penetrate
fingernails Delta-Atracotoxins Presynaptic neurotoxins - open sodium
channels - inducing action potentials Autonomic storm - endogenous Ach
norepinephrine & epinephrine.
EnvenomationEnvenomation
Painful Bite - acidic pH, large size of fangs Onset rapid - median 28 min, 2 cases after 2
hours (pressure dressing) Early symptoms: periorbital paresthesias,
facial muscle twitching, vomiting, diaphoresis, salivation, dyspnea
Agitation, confusion, coma, hypertension, metabolic acidosis, mydriasis, fasciculations
Increased ICP - death
Painful Bite - acidic pH, large size of fangs Onset rapid - median 28 min, 2 cases after 2
hours (pressure dressing) Early symptoms: periorbital paresthesias,
facial muscle twitching, vomiting, diaphoresis, salivation, dyspnea
Agitation, confusion, coma, hypertension, metabolic acidosis, mydriasis, fasciculations
Increased ICP - death
Funnel Web TreatmentFunnel Web Treatment
Pressure immobilization bandage Antivenom purified rabbit IgG Developed in 1981 in Melbourne Fast acting and effective Hospitalization rates have changed
from 14 days to 3 days on average with no deaths since its availability.
Pressure immobilization bandage Antivenom purified rabbit IgG Developed in 1981 in Melbourne Fast acting and effective Hospitalization rates have changed
from 14 days to 3 days on average with no deaths since its availability.
First AidFirst Aid
Keep victim calm and still if possible
Immobilize the bitten area and keep it lower than the heart. Remove rings.
Pressure dressing - NOT tourniquet
Get patient to definitive care - antivenin - Sooner the better!
Keep victim calm and still if possible
Immobilize the bitten area and keep it lower than the heart. Remove rings.
Pressure dressing - NOT tourniquet
Get patient to definitive care - antivenin - Sooner the better!
Other Australian Mygalomorph spidersOther Australian Mygalomorph spiders Mouse Spider - local pain, local
paresthesias Trap door spider - minor effects only
Mouse Spider - local pain, local paresthesias
Trap door spider - minor effects only
60 yo m collecting yard waste next to house60 yo m collecting yard waste next to house Feels a sharp bite on forearm Noticed a medium sized spider with
prominent abdomen Red spot on underside of abdomen Hourglass shaped Should he worry?
Feels a sharp bite on forearm Noticed a medium sized spider with
prominent abdomen Red spot on underside of abdomen Hourglass shaped Should he worry?
LatrodectusLatrodectus
HistoryHistory
Slight initial pain: pinch or pinprick
In 1 hour, systemic symptoms begin and may last for a few days.
Muscle cramping - local and large muscle groups - abdomen, back, thighs.
Nausea and vomiting Headache Anxiety
Slight initial pain: pinch or pinprick
In 1 hour, systemic symptoms begin and may last for a few days.
Muscle cramping - local and large muscle groups - abdomen, back, thighs.
Nausea and vomiting Headache Anxiety
PhysicalPhysical
Abnormal vital signs, Hypertension, Tachycardia
Diaphoresis: local or remote from site of envenomation
Tiny fang marks may be visible Bite appearance: small circle of
redness, swelling around immediate bite site. May have blanching with red border
Abnormal vital signs, Hypertension, Tachycardia
Diaphoresis: local or remote from site of envenomation
Tiny fang marks may be visible Bite appearance: small circle of
redness, swelling around immediate bite site. May have blanching with red border
Bite after 1 hourBite after 1 hour
Physical Exam - continuedPhysical Exam - continued
Abdominal rigidity - acute abdomen.
Neurotoxic effects, weakness, fasciculations, and ptosis
Latrodectus facies, with facial muscle spasm of, edematous eyelids, & lacrimation. Mimics an allergic reaction.
Abdominal rigidity - acute abdomen.
Neurotoxic effects, weakness, fasciculations, and ptosis
Latrodectus facies, with facial muscle spasm of, edematous eyelids, & lacrimation. Mimics an allergic reaction.
Grading BitesGrading Bites
Grade 1 - Mild envenomation, Localized pain at bitesite, Normal vitals
Grade 2 - Moderate envenomation: Muscle pain in the bitten arm or legMuscle pain may extend to abdomen if bitten on leg, or to the chest with bite on arm.Local diaphoresis of envenomation site or involved extremityNormal vital signs
Grade 1 - Mild envenomation, Localized pain at bitesite, Normal vitals
Grade 2 - Moderate envenomation: Muscle pain in the bitten arm or legMuscle pain may extend to abdomen if bitten on leg, or to the chest with bite on arm.Local diaphoresis of envenomation site or involved extremityNormal vital signs
Grade 3 LatrodectismGrade 3 Latrodectism
Severe envenomationGeneralized muscular pain in the back, abdomen, and chestDiaphoresis remote from envenomation siteAbnormal vital signs (blood pressure >140/90 mm Hg, pulse >100)Nausea and vomiting Headache
Severe envenomationGeneralized muscular pain in the back, abdomen, and chestDiaphoresis remote from envenomation siteAbnormal vital signs (blood pressure >140/90 mm Hg, pulse >100)Nausea and vomiting Headache
AntiveninAntivenin
Antivenin Latrodectus mactans - horse serum (Merck product)
Consider for patients with grade 2 or grade 3 envenomations in whom narcotics do not control pain and are low risk for allergic reactions
Rec for certain patient groups, such as children and elderly persons
skin testing for possible allergic reaction to the antivenom.
Antivenin Latrodectus mactans - horse serum (Merck product)
Consider for patients with grade 2 or grade 3 envenomations in whom narcotics do not control pain and are low risk for allergic reactions
Rec for certain patient groups, such as children and elderly persons
skin testing for possible allergic reaction to the antivenom.
Antivenin PrecautionsAntivenin Precautions
Mortality from widow spider envenomation is extremely rare, and some argue against administration of antivenom when treatment may be more dangerous than the injury
some recommend routine premedication with antihistamines (H1 and H2 blockers)
black widow spider envenomation is associated with abruptio placentae and fetal demise; benefits of antivenom administration in pregnancy must be weighed against risks
Mortality from widow spider envenomation is extremely rare, and some argue against administration of antivenom when treatment may be more dangerous than the injury
some recommend routine premedication with antihistamines (H1 and H2 blockers)
black widow spider envenomation is associated with abruptio placentae and fetal demise; benefits of antivenom administration in pregnancy must be weighed against risks
The dreaded brown recluseThe dreaded brown recluse Necrotic skin ulceration Spiders get a bad rap - blamed for
every little skin infection, folliculitis
Necrotic skin ulceration Spiders get a bad rap - blamed for
every little skin infection, folliculitis