Lizard bites

Background

Glia monster.

Mexican Beaded Lizard.

• Only two venomous lizard species in the world
• Venom secreted from glands in mucosa of lower jaw
• ~70% of bites involve envenomation
• Dislodged teeth are common
• Tenacious biters that frequently involve forceful removal

Gila Monster

• Species: Heloderma suspectum
• Geographic Distribution: Southwestern United States and Northwestern Mexico

Mexican Beaded Lizard

• Species: Heloderma horridum
• Geographic Distribution: Central and Southern Mexico

Clinical Features

• Initial symptoms include localized throbbing and burning pain with progressive edema
• Systemic symptoms can include gastrointestinal distress, diaphoresis, paresthesia and dyspnea
• Bradykinin release can cause tachycardia and hypotension

Differential Diagnosis

Envenomations, bites and stings

• Hymenoptera stings (bees, wasps, ants)
• Mammalian bites
  • Closed fist infection (Fight bite)
  • Dog bite
• Marine toxins and envenomations
  • Toxins (ciguatera, neurotoxic shellfish poisoning, paralytic shellfish poisoning, scombroid, tetrodotoxin
  • Stingers (stingray injury)
  • Venomous fish (catfish, zebrafish, scorpion fish, stonefish, cone shells, lionfish, sea urchins)
  • Nematocysts (coral reef, fire coral, box jellyfish, sea wasp, portuguese man-of-war, sea anemones)
  • Phylum porifera (sponges)
  • Bites (alligator/crocodile, octopus, shark)
• Scorpion envenomation
• Reptile envenomation
  • Snake bites
    • Crotaline (Pit Vipers)
    • Elapidae (Coral Snakes)
  • Lizard bites
• Spider bites
  • Black widow
  • Brown recluse
  • Tarantula
  • Funnel-web spider bite
  • Armed spider bite

Evaluation

Workup

• CBC, BMP, and coagulation studies to rule out DIC
• Consider EKG
• X-ray of site to rule out retained tooth fragment

Diagnosis

• Typically a clinical diagnosis

Management

• Removal of lizard
  • Lizards have very tenacious bites and need active detachment
  • Place under running hot water or use tongs or a stick
• IV Fluids as needed; if persistent hypotension, consider vasopressors
• Explore, clean and irrigate wound
• Tetanus prophylaxis
• Daily dressing changes with topical antiseptic
• Antibiotics not routinely needed

Disposition

• If normal vitals and labs, can be discharged home after ED observation
• Observation is recommended if patient has any vital sign or lab abnormalities suggestive of envenomation

See Also

• Envenomations, bites and stings