Lizard Envenomation Treatment & Management

No evidence-based recommendations have been determined for field management of lizard envenomation.

If the lizard remains attached to the victim, it immediately should be removed as soon as possible. Unfortunately mechanical methods for detaching the animal may facilitate injury to the animal including disloged teeth remaining in the wound. Briefly holding flame under the animal's chin/neck or submerging the lizard in cold water has been successful previously. Care should be exercised to prevent additional bites to the victim or rescuer as the lizard may feel threatened.

If possible, the wound should be washed quickly with copious running water. Place a dressing on the wound to control any active bleeding, and apply a splint to limit movement of the extremity. The limb can be kept at approximately heart level during transport to medical care.

No evidence to recommend the use of constrictive bands, compressive dressings, or suction is available. Tourniquets should not be used.

Do not make any incisions into the already damaged tissues.

Although ice has been used to reduce pain, it can exacerbate local vasospasm.

Victims showing evidence of shock should be kept in a supine position with legs elevated. If oxygen and intravenous fluids are available, these should be administered during transport to the hospital.

Closely monitor vital signs.

Immediately begin cardiac and pulse oximetry monitoring. ^[13]

Establish 2 IV lines with isotonic sodium chloride solution.

If hypotension occurs, begin aggressive fluid resuscitation. If vital signs fail to improve with adequate crystalloid infusion (eg, 20-40 mL/kg), vasopressor agents may be necessary.

Wound care

Clean the wounds with soap and water, and evaluate them for retained foreign bodies.

A local anesthetic, such as lidocaine (without epinephrine), can be injected at the bite site to aid in pain control and to assist in exploration of the wounds for retained teeth or damage to underlying structures. ^[14] Regional nerve blocks and judicious use of narcotics can be helpful in controlling pain. ^[15] A non–histamine-releasing narcotic, such as fentanyl, may be preferable.

The extremity should be splinted and kept at (or slightly above) the patient's heart level to reduce edema.

Because of the significant local tissue trauma, prophylactic broad-spectrum antibiotics may be administered for a few days, although this treatment is controversial and untested.

Tetanus immunization status should be updated as necessary.

Inpatient

Admit patients with a significant systemic reaction or with abnormal lab studies and/or ECG findings, to a monitored setting.

The bitten extremity should be placed in a well-padded splint and elevated to the patient's heart level or higher to reduce edema.

Institute standard daily wound care, including cleansing, topical antibiotic application, and dressing.

Physical therapy can help speed the return to full function.

Admission for pain control may be warranted.

Transfer

Transfer of victims with evidence of severe envenoming to a center with experience in dealing with these cases may be prudent. Consultation with an experienced provider is recommended (see Consultations).

Outpatient

All victims of helodermatid bites should be observed in the ED for at least 6 hours for development of systemic or severe symptoms.

Reliable patients who are relatively asymptomatic, with normal vital signs and lab findings, can be discharged with instructions to return for any worsening symptoms. A responsible adult should be available to help the patient return if necessary.

Provide instructions for wound care (eg, wash the wounds twice per day with soap and water; apply a topical antibiotic ointment and dressing).

Signs and symptoms of wound infection should be discussed with the patient.

Arrange a follow-up appointment for a wound check in 24-48 hours.

Give a prescription for antibiotics (eg, cephalexin) to patients who are being prophylactically treated.

A prescription for a narcotic analgesic, such as hydrocodone, may be appropriate.

 

Consult an expert in reptile envenomations to assist in management, as necessary. In the US, the local Poison Control Center (1-800-222-1222) can help direct or facilitate appropriate care.  An excellent resource for assistance is the University of Arizona Poison and Drug Information Center (telephone: 520-626-6016).