Bites and Stings :Bites and Stings


Bites and Stings :Bites and Stings Arthropods Insects Spiders Scorpions Ticks Reptiles Pit Vipers Coral Snakes Venomous Marine Life


Phylum Arthropoda :Phylum Arthropoda Joint-legged animals At least 750,000 species Three times number of all other animal species combined Most successful life forms on earth Insects, spiders, scorpions, ticks, centipedes, etc.


Venomous Bites and Stings :Venomous Bites and Stings Parrish, 1950-59 Review of coroner’s records 460 deaths 50% insect sting 30% snake bite 14% spider bite 6% other


Hymenoptera :Hymenoptera Bees, wasps, hornets, yellowjackets, ants Problems Allergic reactions Anaphylaxis Toxic venom effects (rare) About 25 deaths/year Honeybees 50% Yellowjackets and other wasps 50%


Hymenoptera :Hymenoptera 0.4% of population at risk for serious allergic reaction Most give history of progressive severity of response Some deny prior stings or report only normal reactions 50% of 2006 sting patients experiencing allergic reaction had NO previous warning symptoms!


Hymenoptera :Hymenoptera Local reaction Sharp, burning pain Itching Edema Extensive reactions may involve entire extremity Stings to tongue/throat may cause loss of airway


Hymenoptera :Hymenoptera Systemic reactions Immediate Mild: Diffuse itching, urticaria, swelling distant from sting site, flushing Severe: Laryngeal edema, severe bronchospasms, profound hypotension


Hymenoptera :Hymenoptera Systemic reactions Delayed 1 to 48 hours after sting May be life threatening


Hymenoptera :Hymenoptera Treatment Immediate Remove stinger (scrape) Manage airway Oxygen Support BP with fluid Epinephrine Antihistamines Steroid


Hymenoptera :Hymenoptera Treatment Prevent subsequent sting Avoid exposure No bright clothing Avoid sweet fragrances Avoid eating sweets outdoors


Hymenoptera :Hymenoptera Treatment Self treatment Medic Alert Tags Anaphylaxis kit Hyposensitization therapy


Lepidoptera :Lepidoptera Pus caterpillar Larval form of the M. opercularis moth. Seasonal: one stage in June/July and one in October/November 1921 San Antonio , so abundant public schools were ordered to close while pest was brought under control.


Slide 14:Pus caterpillar


Slide 15:Pus caterpillar


Pus Caterpillar :Pus Caterpillar Distribution: widely throughout Southern states. Host plants: Citrus trees, hackberry, elm, plum, sycamore and oak. Stages: Adult--yellowish brown, wings have long wavy hairs with white streaks Larva--5 or 6 instars (molts), ~1 inch. Cocoon--Larva sheds hairs as it spins and are interwoven with the silk.


Pus Caterpillar :Pus Caterpillar Life history: First generation--Max number of grown larvae in June and July Second generation--Max number of grown larvae in September and October Stings: Caused by inadvertently pressing caterpillar against exposed part of body Severity of reaction varies among individuals and also depends on amount of pressure applied


Pus Caterpillar :Pus Caterpillar Toxicology Poorly understood Never been extensively studied 6 rows of spines underneath long hairs Spines contain toxin that is secreted into victim upon touch


Clinical Presentation :Clinical Presentation Intense local burning pain Erythema, swelling Severe proximally radiating pains Hemorrhagic lesion may develop forming grid-like pattern Swollen lymph nodes common Pain may last 24 hours to 5 days Allergic reactions unlikely


Slide 20:Grid-like pattern


Treatment :Treatment Application of adhesive tape is successful in removing spines Local wound care Intermittent ice application Morphine or meperidine may be required for pain control 10mL of 10% IV calcium gluconate was shone to provide pain relief in a small study. Hydrocortisone used empirically. Pruritus and urticaria -- Diphenhydramine


Spiders :Spiders 37,000 species All are venomous 50 U.S. species can bite humans 15 U.S. species will produce symptoms Only two are dangerous Black widow (Latrodectus mactans) Brown recluse (Loxosceles reclusa)


Spiders :Spiders Parrish, 1950-59 65 spider bite deaths in U.S. Brown recluse 2 Black widow 63


Black Widow :Black Widow Throughout U.S. As far north as Oregon, New York Common in South, Southwest Irregular webs in wood piles, under rocks, in trash dumps, in outdoor structures Occasionally in houses Females rarely leave web Only females can bite humans


Black Widow :Black Widow Neurotoxic venom More potent than pit viper venom Binds to nerve-ending calcium channels Triggers neurotransmitter release Blocks neurotransmitter re-uptake Inhibits normal nerve impulse transmission Produces low serum calcium


Black Widow :Black Widow Immediate sharp, stinging pain Muscle cramping in 15 minutes to 2 hours Upper extremity: pleuritic chest pain Lower extremity/genitalia: abdominal pain, rigidity


Black Widow :Black Widow Muscle twitching, weakness, paralysis, drooping eyelids Sweating, tearing, salivation, increased bronchial secretions Anxiety, headache, restlessness, dizziness, nausea, vomiting, hypertension (? hypertensive crisis) Edema, skin rash, conjunctivitis, itching Shock, respiratory depression


Black Widow :Black Widow Symptoms peak in a few hours, then diminish Usually last < 24 hours Some symptomatic up to 4 days 5% have delayed hypersensitivity 2 to 3 days post-bite Mortality rate unknown Most recover completely


Black Widow :Black Widow Treatment Local cold application Relieve muscle cramping Calcium gluconate Methocarbamol (Robaxin) Diazepam Narcotics


Black Widow :Black Widow Treatment Antivenin indicated for: Very young Very old Hypertensive reactions Acute respiratory distress


Black Widow :Black Widow Admit if: Treated with antivenin Very young Very old Persistent symptoms develop


Brown Recluse :Brown Recluse Southeast and South Central U.S. Related species in desert Southwest Shy, nocturnal Dark closets, basements May live on floors, behind furniture in houses Incidence of bite unknown


Brown Recluse :Brown Recluse Local effects Tissue necrosis Leukocyte infiltration of bitten area Edema Hemorrhage Thrombosis


Brown Recluse :Brown Recluse Systemic effects Breakdown of red cells Elevated white cell count Decreased platelet count


Brown Recluse :Brown Recluse Local signs and symptoms No pain or only mild stinging Within 2 hours: Local pain, blue-gray constrictive halo 12 to 18 hours: Bleb formation, growing ischemic zone 5 to 7 days: Aseptic necrosis, eschar formation, necrotic ulcer Severe lesions up to 30 cm in diameter


Brown Recluse :Brown Recluse Mild systemic signs and symptoms Fever, chills Malaise Nausea, vomiting Joint pain


Brown Recluse :Brown Recluse Severe systemic effects (rare) Disseminated intravascular coagulation Renal failure Convulsions Heart failure Death


Brown Recluse :Brown Recluse Prehospital management Local cold application Wound cleansing Padded splint, bulky dressing


Brown Recluse :Brown Recluse Hospital management Supportive and symptomatic care Debride full thickness lesions with subsequent grafts Dapsone may improve outcomes Antivenin under development Outcomes NOT improved by Early excision Steroids


Scorpions :Scorpions 40 U.S. species Only one potentially lethal (Centuroides sculpturatus) Primarily in Arizona Occasionally in western New Mexico, southeast California, northern Mexico, far West Texas 1929-48: More deaths in Arizona than any other venomous animal No deaths since 1969


Centuroides sculpturatus :Centuroides sculpturatus Neurotoxic venom Acts on neuronal synapse and neuro-muscular junction Increased neuron sodium permeability Neurotransmitter release at synapses Increased acetylcholine release at neuromuscular junction


Centuroides sculpturatus :Centuroides sculpturatus Local signs, symptoms No local swelling or inflammation Local pain with hyperesthesia


Centuroides sculpturatus :Centuroides sculpturatus Systemic signs, symptoms Extreme restlessness, agitation Roving eye movements Poor coordination, slurred speech, difficulty swallowing Salivation, wheezing, stridor Tachycardia, tachypnea, hypertension, nausea, vomiting


Centuroides sculpturatus :Centuroides sculpturatus Treatment Symptomatic, non-specific Antivenin Analgesia Narcotics, benzodiazepines safe in SMALL doses Large sedative, narcotic doses may cause respiratory depression


Ticks :Ticks Rocky mountain spotted fever First identified in Idaho, Montana Most cases now in: Carolinas Virginia Georgia Tennessee Maryland Oklahoma


Ticks :Ticks Rocky mountain spotted fever 95% of cases in spring, summer Caused by: Rickettsia rickettsii Tick species responsible: West: wood tick (Dermacentor andersoni) Southeast: dog tick (Dermacentor variabilis)


Rocky Mountain Spotted Fever :Rocky Mountain Spotted Fever Signs, symptoms Fever Headache 2nd to 6th day: Pink, spotty rash near ankles, wrists Over 6 to 12 hours: Rash spreads to armpits, buttocks, trunk, neck, face


Rocky Mountain Spotted Fever :Rocky Mountain Spotted Fever Mild cases recover in 20 days Untreated mortality: 8 to 20% Treated mortality: 4% Antibiotic therapy: Chloramphenicol Tetracycline


Ticks :Ticks Lyme disease Originally identified in Lyme, Connecticut Incidence may approach that of Rocky Mountain Spotted Fever Caused by Borrelia burgdorferi Responsible ticks: Ixodes species Amblyomma americanum


Lyme Disease :Lyme Disease Phase one: Large circular lesions (Erythema chronica migrans) Pain in muscles, joints Fatigue Headache Fever Malaise Swollen lymph nodes Diffuse erythema Conjunctivitis Periorbital edema


Lyme Disease :Lyme Disease Phase two (weeks to months later) Pericarditis Myocarditis AV conduction problems Meningoencephalitis Cranial, peripheral neuropathies Phase three: Chronic, recurrent arthritis


Lyme Disease :Lyme Disease Antibiotic therapy during phase one prevents later stages of disease Agents Adults: tetracycline Children: penicillin or erythromycin


Tick Paralysis :Tick Paralysis Neurotoxin in saliva of pregnant female hard ticks Blocks acetylcholine release at neuromuscular junction Weakness, decreased reflexes, ascending paralysis May progress to respiratory paralysis in 12 to 24 hours


Tick Paralysis :Tick Paralysis Usually in summer months Typically female child with long hair Locate, remove ticks


Whipscorpions :Whipscorpions Live under logs, rocks, bark Active at night Mastigoproctus giganteus (Vinegaroon) Can pinch Sprays vinegar when surprised 84% acetic acid Can blister human skin


Tarantulas :Tarantulas Large, wandering predatory spiders About 30 U.S.species Relatively docile Rarely bite Bite produces local pain, edema, lymph node swelling Flick irritating abdominal hairs if bothered


Solifugids :Solifugids Sun spiders, wind spiders, Child of the Earth Over 100 species in Southwest Active during day Large chelicerae (mouth parts) Non-venomous, but can pinch


Snakes :Snakes 45,000 bites per year in U.S. 8,000 bites from venomous snakes 25% are dry strikes 10 deaths


Venomous Snakes :Venomous Snakes Types of U.S.venomous snakes Pit vipers (Crotalidae) Rattlesnakes Copperheads Water moccasins (cotton mouth) Coral snakes (Elapidae)


Venomous Snakes :Venomous Snakes Pit vipers Heavy bodies Diamond-shaped heads Vertical, elliptical pupil Heat sensing pit on upper lip between eye and nostril Erectile fangs Venom primarily hemotoxic, necrotoxic (exception: Mojave rattler)


Venomous Snakes :Venomous Snakes Rattlesnakes 13 Species 7,000 bites/year 9 to 10 fatalities Most deaths are from western diamondback or eastern diamondback


Venomous Snakes :Venomous Snakes Copperhead Agkistrodon contortrix Deaths VERY rare Minimal edema and pain


Venomous Snakes :Venomous Snakes Water moccasin Agkistrodon piscivorus leucostoma Causes an average of one death a year Produces mild systemic symptoms, potential for severe local tissue injury and necrosis


Epidemiology :Epidemiology 25% are dry bites 25-75% of venom is discharged in a bite Replenished in 3 to 4 weeks Extremities are most common bite site Most common victims: Children Intoxicated adults Snake handlers and collectors


Epidemiology :Epidemiology Risk Factors Tequila Testosterone Tattoo Teeth (more missing = greater chance) Trailer park T-shirt (Heavy Metal Band)


Pit Viper Envenomation :Pit Viper Envenomation Pain, swelling at bite site Progressive edema of bitten extremity Bruising of bitten area Formation of blood-filled vesicles


Pit Viper Envenomation :Pit Viper Envenomation Weakness, sweating, nausea, vomiting Tachycardia Hypotension, shock Prolonged clotting times Bleeding gums Hematemesis, melena, hematuria


Pit Viper Envenomation :Pit Viper Envenomation Numbness, tingling, and neurological symptoms may develop Mojave rattlesnake Produces few local effects May cause a systemic intoxication syndrome Decreased level of consciousness Cranial nerve dysfunction Respiratory paralysis


Grading of Pit Viper Envenomation :Grading of Pit Viper Envenomation Dry Bite Local abrasion or bite mark without severe pain or swelling Normal vital signs Normal coagulation studies Normal platelet count


Grading of Pit Viper Envenomation :Grading of Pit Viper Envenomation Mild Envenomation Local pain and swelling Normal vital signs Normal to mildly abnormal coagulation studies Platelet count >100,000


Grading of Pit Viper Envenomation :Grading of Pit Viper Envenomation Moderate Envenomation Local pain and moderate swelling Normal vital signs Abnormal coagulation studies (doubling of pT and pTT) Thrombocytopenia (platelets <100,000)


Grading of Pit Viper Envenomation :Grading of Pit Viper Envenomation Severe Envenomation Initial presentation consistent with shock Altered mental status with or without normal vital signs and/or poor peripheral perfusion Abnormal coagulation studies (unmeasurable pT and pTT) Thrombocytopenia (platelets <20,000)


Venomous Snakes :Venomous Snakes Coral snake Thin-bodied Small, rounded head Brightly colored Small, non-erectile fangs Injects venom by chewing Venom primarily neurotoxic


Venomous Snakes :Venomous Snakes Coral snake Two species Arizona coral snake Non-aggressive No recorded human deaths Eastern coral snake Several bites reported annually (mostly Florida, Texas) About one death every 5 years


Coral Snake Envenomation :Coral Snake Envenomation Little, no pain Little, no swelling Paresthesias around bitten area Muscular incoordination, weakness


Coral Snake Envenomation :Coral Snake Envenomation Increased salivation Difficulty swallowing, talking Visual disturbances Respiratory distress, failure Shock, cardiovascular collapse Most deaths occur from respiratory arrest within 36 hours


Snakebite Management :Snakebite Management Calm victim Oxygen, monitor, IV Proximal constricting band ( + ) Clean, bandage wound Immobilize bitten area, keep dependent Watch constricting bands, bandages, splints carefully for vascular compromise 2o to edema Transport


Snakebite Management :Snakebite Management Do NOT Apply ice Apply arterial tourniquet Cut and suck Use electrical shock Actively attempt to locate a venomous snake Bring a live venomous snake to the hospital


Venomous Marine Life :Venomous Marine Life Jellyfish, Portuguese man-of-war, fire corals Stinging cells (nematocysts) in tentacles Intense, burning pain Red, hemorrhagic lesions Nausea, vomiting Fever, chills Respiratory distress, wheezing, stridor Hypotension, shock Cardiovascular collapse Kill stinging cells with alcohol or vinegar


Venomous Marine Life :Venomous Marine Life Venomous Fish Sting ray Scorpionfish (Lion fish, Stonefish) Immerse stung area in hot water


Venomous Marine Life :Venomous Marine Life Sea Urchins Immerse injured area in hot water Use acetic acid to dissolve embedded spines Larger spines may require surgical removal