Report on envenomation by a Gila monster (Heloderma suspectum) with a discussion of venom apparatus, clinical findings, and treatment

Abstract

Human envenomations by Heloderma species are a rare but clinically important medical problem. We report a case of an adult male bitten on the left hand by a 50-cm male, captive specimen of Heloderma suspectum (Gila monster). Immediate signs and symptoms included pain at the bite site radiating into the arm and axilla and swelling of the hand and forearm. Systemic complaints of nausea, diaphoresis, and dizziness (without a decrease in blood pressure) lasted approximately 1 hour, and laboratory studies were normal. The patient's course was uneventful except for persistent hyperesthesia, which eventually abated. Two types of helodermatid bites produce distinct clinical pictures. The chewing bite potentially causes more envenomation than the slashing bite. The venom contains a number of protein and nonprotein components including serotonin, a bradykinin-releasing substance, protease, hyaluronidase, helodermin, and gilatoxin. The clinical presentation of a helodermatid bite can include pain, edema, hypotension, nausea, vomiting, weakness, and diaphoresis. No antivenin is commercially available. Treatment is supportive, and although first aid measures such as suction or compression may impede venom movement, they are unproved. Cryotherapy, tourniquet, and excision are dangerous and should not be used.

Mast cell chymase reduces the toxicity of Gila monster venom, scorpion venom, and vasoactive intestinal polypeptide in mice

“…In contrast to snake envenomation, human bites by lizards are relatively rare but appear to be increasing in parallel with improvements in captive-breeding techniques (13). Envenomation by the Gila monster is not ordinarily fatal to adult humans, but results in intense pain, edema, weakness, and nausea associated with hypotension or tachycardia and can even cause anaphylactic shock or myocardial infarction (13)(14)(15)(16)(17). These signs and symptoms probably reflect powerful physiological effects of the kallikrein-like peptides and other bioactive peptides in Helo-omation (18,23).…”

Gila Monster Envenomation: A Review for the Emergency Medicine Physician

“…7 In the United States, the Gila monster's habitat extends from southwestern Utah through southern Nevada, extreme southeastern California, most of Arizona and the south western portion of New Mexico . 5 However, cases of wild Gila envenomation have been reported as far east as Missouri. 8 In Mexico, the Gila monster mostly resides in Sonora.…”

“…The venom apparatus consists of a pair of venomous glands located along the anterior aspect of the mandible, venom ducts and edge teeth. 5,6 The venom gland is found along the anterior half of the lower jaw and can be noted by a swelling of the lower jaw. 5,6 It is encompassed by a capsule of fibrous tissue which terminates into septae that separate the gland into four major lobes.…”

“…5,6 The venom gland is found along the anterior half of the lower jaw and can be noted by a swelling of the lower jaw. 5,6 It is encompassed by a capsule of fibrous tissue which terminates into septae that separate the gland into four major lobes. 5,6 The venom is then passed through a network of ducts and stored in a reservoir, called the dental sac, adjacent to the teeth.…”

“…4 Local symptoms include intense pain and paresthesia while systemic symptoms include nausea, diaphoresis, dizziness and hypotension. 5 Treatment typically includes removal of the lizard, local wound care and aggressive resuscitation if…”