AUTHOR AND EDITOR INFORMATION

Section 1 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
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INTRODUCTION

Section 2 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Background

Envenomation by some rattlesnakes, such as the Mohave rattlesnake (formerly Mojave rattlesnake) (Crotalus scutulatus), may cause a different clinical presentation than that generally encountered after most rattlesnake bites. In addition, other species, such as the Southern Pacific rattlesnake Crotalus oreganus helleri, (formerly Crotalus viridis helleri), may cause signs and symptoms consistent with typical rattlesnake envenomation combined with signs and symptoms similar to Mohave rattlesnake envenomation. (See Snake Envenomations, Rattle for a more complete discussion of typical rattlesnake envenomation.)

Mohave rattlesnakes inhabit desert areas of the southwestern United States and central Mexico. Specimens with type A venom, which cause a different pattern of injury than other rattlesnakes, have been reported in southern California, Nevada, Utah, Arizona, Texas, and New Mexico. Populations with venom B and intergrades of types A and B venom have been found in south-central Arizona, around Phoenix and Tucson.

The Mohave rattlesnake may be difficult to distinguish from the western diamondback rattlesnake (Crotalus atrox), which inhabits an overlapping geographical range. Some Mohave rattlesnakes are greenish, but they may have a similar color as western diamondbacks. In the Mohave rattlesnake, the diamond pattern fades into bands along the caudal third of the back, whereas the diamonds continue to the tail in the western diamondback. The Mohave rattlesnake's white rings encircling the tail are much wider than the narrow black rings, whereas western diamondbacks have much more predominant black rings. The postocular stripe extends posteriorly above the mouth in the Mohave but intersects the corner of the mouth in the western diamondback. In Mohave rattlesnakes, supraocular scales are separated by fewer than 4 scales at their closest point. In western diamondbacks, at least 4 scales (usually >4) separate the supraocular scales.

Other rattlesnakes in the Mohave rattlesnake's range and niche are distinguishable by the absence of a dorsal diamond pattern with light margins, black and white tail rings, facial stripes, or by the same criteria used to distinguish Mohave rattlesnakes from western diamondbacks.

Pathophysiology

Venom A populations of Mohave rattlesnakes possess Mohave toxin, which has been experimentally shown to induce neurotoxic effects. Mohave toxin or a similar toxin has been detected in the venom of other rattlesnake species. This toxin impairs presynaptic acetylcholine release. Mohave toxin may cause severe neurologic effects clinically, although this presentation has been reported only a few times in the literature. Envenomation by several other species of rattlesnakes has been reported to cause serious neurologic signs and symptoms (eg, severe motor weakness, respiratory difficulty).

Venom A Mohave rattlesnakes cause less local injury and less hemorrhagic/proteolytic effects than other rattlesnakes. In contrast, venom B specimens cause local, proteolytic, and hemorrhagic effects typical of other rattlesnakes. Severe rhabdomyolysis with myoglobinuric renal failure has been reported with Mohave rattlesnake envenomation. This article focuses mainly on envenomation by venom A populations of Mohave rattlesnakes.

Mortality/Morbidity

Mohave toxin is one of the most lethal venom components found in US snakes.

• Venom B populations are less lethal than venom A populations.
• One death has been attributed to a Mohave rattlesnake in the Annual Report of the American Association of Poison Control Centers, although a number of deaths have been documented.
• Most documented deaths are associated with bites in which the bitten individual was intentionally interacting with the snake and when a delay occurred in seeking medical care.

Sex

Males are bitten more commonly than females.

Age

Young adults are most commonly bitten.

CLINICAL

Section 3 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

History

• In some cases, it may be helpful to know where the bite occurred (geographically) and whether venom A populations are known to occur in the area.
• Pain around the bite site
• Redness around the bite site
• Swelling (which may be less with Venom A Mohave rattlesnakes)
• Nausea, vomiting, or diarrhea
• Difficulty breathing
• Chest pain
• Neurologic symptoms
• • Weakness
  • Paresthesias
  • Syncope, near syncope

Physical

• Fang marks
• Edema and erythema (Generally, local tissue effects are much less pronounced than typically observed after rattlesnake envenomation.)
• Tenderness surrounding bite site
• Tachycardia
• Hypotension/shock
• Myokymia (muscle movement, fasciculations)
• Neurologic effects
• • Cranial nerve palsies
  • Ptosis
  • Diplopia
  • Dysphagia
  • Dysphonia
  • Motor weakness (severe, generalized)
  • Respiratory paralysis
  • Lethargy

Causes

A large percentage of bites occur when the snake is handled, kept as a pet, or abused. These bites are considered intentionally interactive.

DIFFERENTIALS

Section 4 of 11  

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• Clinical
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• Follow-up
• Miscellaneous
• Multimedia
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WORKUP

Section 5 of 11  

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• Follow-up
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Lab Studies

• Rhabdomyolysis may occur from severe envenomations, but is best described after canebrake (Crotalus horridus atricaudatus) and Mohave (C scutulatus) rattlesnake envenomations. Rhabdomyolysis may lead to myoglobinuric renal failure and subsequent electrolyte abnormalities, such as hyper- or hypokalemia or hypocalcemia.
• • Creatine kinase (CK)
  • Electrolytes
  • Blood urea nitrogen (BUN) and creatinine
  • Calcium
  • Phosphorus
  • Urinalysis
• Mohave toxin has less effect on coagulation than other rattlesnake venoms. However, coagulopathies may occur. (See Snake Envenomations, Rattle for suggested laboratory tests.)
• For respiratory difficulty, consider arterial blood gas (ABG) measurements.
• Obtain laboratory and other diagnostic data on a case-by-case basis. Factors to consider may include severity of envenomation, physician preference, and cost.

Imaging Studies

• Radiographic findings may reveal teeth or fangs retained in the wound.

Other Tests

• Obtain an electrocardiogram (ECG), if indicated. Although cardiac enzymes may rise with severe rhabdomyolysis, current literature suggests that this does not reflect cardiac injury.
• Skin testing
• • Skin testing is not necessary before administering Crotaline Fab antivenom (CroFab) therapy.
  • Intracutaneous injection of 0.02-0.03 mL of a 1:10 dilution of horse serum or antivenom is recommended in the Antivenin Crotalidae Polyvalent package insert.
    • A positive test result is manifested by the development of a wheal within 5-30 minutes. However, skin testing is unreliable. False-positive and false-negative results may occur.
    • Using antivenom (further diluted to 1:100) rather than the horse serum control that is supplied may increase the sensitivity and specificity of the test.
    • Skin testing may be considered variably useful in predicting immediate hypersensitivity in cases of moderate envenomation when it is uncertain if the need for antivenom outweighs the risk of anaphylaxis.
    • Skin testing may sensitize individuals at risk for future exposures to antivenom, or it may precipitate anaphylaxis.
    • If antivenom is clearly indicated, begin administration as described below, without waiting to perform a skin test.

Procedures

• Central venous or interosseous access may need to be obtained. However, avoid placing a central line in a noncompressible site (eg, subclavian) because of the risk of bleeding from venom-induced coagulopathy.
• Fasciotomy probably is not indicated in Mohave (venom A) envenomation. If severe swelling is noted, suspect envenomation by a snake other than a venom A Mohave rattlesnake and treat accordingly (see Snake Envenomations, Rattle).

TREATMENT

Section 6 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Prehospital Care

Do nothing to injure the patient or impede travel to the ED.

• Provide general support of airway, breathing, and circulation per advanced cardiac life support (ACLS) protocol; use oxygen, monitors, 2 large-bore intravenous lines (but minimize sticks when possible), and fluid challenge. In addition, minimize activity (if possible), remove jewelry or tight-fitting clothes in anticipation of swelling, and transport the patient to the ED as quickly and as safely as possible. Mark and time the border of advancing tenderness and edema often enough to gauge progression. No benefit was demonstrated when a negative pressure venom extraction device (eg, The Extractor from Sawyer Products) was evaluated in recent studies. Incision across fang marks is not recommended. Mouth suction is contraindicated.
• Maintain the extremity in a neutral position of comfort.
• Lymphatic constriction bands and pressure immobilization techniques may inhibit the spread of venom, but whether they improve outcome is not clear. These techniques may actually be deleterious for pit viper envenomation if they increase local necrosis or compartment pressure. Special consideration of these techniques may be warranted for confirmed Venom A Mohave rattlesnake bites because local tissue injury is usually less. However, this application has not specifically been studied. Furthermore, it may not be possible to distinguish Venom A from Venom B snakes just by looking at the snake. The use of tourniquets is not recommended.
• First aid techniques that lack therapeutic value or are potentially more harmful than the snakebite include electric shock, alcohol, stimulants, aspirin, ice application, and various folk and herbal remedies. Cost and risk of acute adverse reactions generally preclude field use of antivenom.
• Although identification of the snake in suspected Mohave rattlesnake bites may be helpful, attempts to capture or kill the snake are not recommended because of the risk of additional injury. If the venomousness of a particular snake is uncertain, consider taking photographs of the snake from a safe distance of at least 6 feet away using a digital or Polaroid camera.

Emergency Department Care

Adequate hydration with intravenous fluids is indicated. Patients with hypotension should be resuscitated first with 2 isotonic sodium chloride solution challenges (eg, 20 mL/kg). Treat persistent shock with colloids, followed by pressors as indicated.

• Patients with Mohave rattlesnake envenomation may present with predominantly systemic and laboratory abnormalities, with only mild local and no hematological effects.
• Administer antivenom for signs of envenomation progression or imminent risk of an acute complication of envenomation (see Complications).
• Because Crotaline Fab antivenom (CroFab) appears safer than Antivenin Crotalidae Polyvalent, it is indicated even if the envenomation is minimal mild. It should be given as a preventative measure if there are any signs of envenomation at all. Do not wait for it to get worse—permanent injury could result.
• Grading envenomations is a dynamic process; administer additional antivenom as indicated by a worsening clinical course. When considering the use of antivenom, weigh the risk of adverse reaction to antivenom against the benefits of reducing venom toxicity.
• Nonenvenomation, ie, dry bite (probably occurs in <10% of rattlesnake bites)
• • Local effects - Puncture wounds only
  • Systemic effects - None
  • Coagulation abnormalities - No laboratory evidence of coagulation abnormalities and no clinical evidence of abnormal bleeding or clotting
• Minimal or mild envenomation
• • Local effects - Swelling, pain, tenderness, and/or ecchymosis confined to the immediate bite area
  • Systemic effects - None
  • Coagulation abnormalities - No laboratory evidence of coagulation abnormalities and no clinical evidence of abnormal bleeding or clotting
• Moderate envenomation
• • Local effects - Swelling, pain, tenderness, and/or ecchymosis extending beyond the immediate bite area but involving less than the entire part
  • Systemic effects - Present but not life threatening; may include nausea, vomiting, oral paresthesias or unusual tastes, fasciculations (myokymia), mild hypotension (systolic blood pressure <90 mm Hg), mild tachycardia (heart rate <150 bpm), and tachypnea
  • Coagulation abnormalities - Laboratory evidence of coagulation abnormalities may be present, but no clinical evidence of abnormal bleeding or clotting exists; rattlesnake venom–induced coagulopathies commonly include thrombocytopenia, decreased fibrinogen, and/or elevated PT
• Severe envenomation
• • Local effects - Swelling, pain, tenderness, and/or ecchymosis extending beyond the entire extremity or threatening the airway
  • Systemic effects - May include severe hypotension or shock, severe tachycardia or tachypnea, respiratory insufficiency, and/or severe altered mental status
  • Coagulation abnormalities - Markedly abnormal with serious bleeding or severe threat of bleeding

Consultations

• The American Association of Poison Control Centers may assist in the management of envenomations.
• For assistance in treating snakebitten patients with crotaline Fab antivenom (CroFab), contact the CroFab hotline at 87-SERPDRUG (877-377-3784).

MEDICATION

Section 7 of 11  

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Be prepared to support the patient's cardiovascular and respiratory systems after a Mohave rattlesnake or similar envenomation.

Drug Category: Antivenom

This agent neutralizes toxins from snakebites. Two antivenoms are available: Crotaline Fab antivenom (CroFab) and Antivenin Crotalidae Polyvalent. CroFab has been available since December 2000. CroFab is manufactured by Protherics, Inc, Nashville, Tenn, and distributed by Fougera, Melville, NY (800-231-0206). Antivenin Crotalidae Polyvalent, manufactured by Wyeth-Ayerst, is still available on the shelves of many hospital pharmacies but is no longer being produced. Whether production of Antivenin will resume is unknown. Meanwhile, another antivenom (Antivipmyn, manufactured by Instituto Bioclon S.A. de C.V.) has been FDA approved for experimental use and is currently undergoing phase II clinical trials.

Drug Name	Antivenin (Crotalidae) Polyvalent
Description	Manufactured by Wyeth-Ayerst. To mix antivenom, dissolve in 10 mL of warm saline by using gentle agitation. May take at least 20-90 min to dissolve. Further dilute it 1:2-4 (eg, mix 10 dissolved vials into a total dilution of 200 mL). Start the infusion at 1 mL/min for 10 min, closely monitoring for signs of allergic reaction. If no allergic reaction occurs, increase the rate to complete the infusion over 1 h. In children, run the infusion at 10 mL/kg/h. Diluting this antivenom in a greater volume of fluid and infusing it slowly may reduce the occurrence acute adverse reactions. Routine premedication with antihistamines (H1 and H2 blockers) is recommended. Pretreatment with epinephrine (1:1000) 0.25 mL SC was shown to reduce acute adverse reactions to antivenom in one series, although the risks of epinephrine should be considered. Pretreatment with steroids is unlikely to prevent immediate reactions but may be helpful later if continued antivenom is indicated despite allergic reaction.
Adult Dose	No envenomation: Do not administer Mild envenomation: Do not administer unless no alternative and it is determined through informed consent of the patient that the benefit likely exceeds the risk Moderate envenomation: 5-10 vials IV initially; administer more prn for progression of venom effects Severe envenomation: 15-20 vials IV initially; administer more prn if lack of improvement in severity
Pediatric Dose	Administer as in adults; higher doses for children have been recommended
Contraindications	Documented hypersensitivity; however, may administer in severe envenomation despite hypersensitivity, although risks, benefits, and alternatives should be considered
Interactions	None reported
Pregnancy	C - Safety for use during pregnancy has not been established.
Precautions	Because of presence of horse serum, agents for emergency treatment of anaphylaxis should be available

Drug Category: Immunizations

Patients should be immunized against tetanus.

Drug Category: Antibiotics

Prophylactic antibiotics are probably not indicated routinely, although they are widely prescribed. Common etiologic bacteria suspected in snakebite wound infections include Pseudomonas aeruginosa species, Enterobacteriaceae species, Clostridium species, and Staphylococcus epidermidis. For infected wounds, empiric therapy may include ciprofloxacin (contraindicated in pediatric patients and pregnant women) as a single agent or a combination of ceftriaxone plus amoxicillin-clavulanate, pending wound culture and sensitivity results. Retained foreign bodies (eg, fang, other tooth) are a common cause of wound infection.

Drug Category: Analgesics

Pain control is essential to quality patient care. It ensures patient comfort and promotes pulmonary toilet. Most analgesics have sedating properties, which are beneficial for patients with painful skin lesions. Use opiates with caution in unintubated patients because Mohave rattlesnake envenomation may cause respiratory difficulties.

Drug Category: Antihistamines

These agents are used to treat minor allergic reactions and anaphylaxis to antivenom or venom. Diphenhydramine may be used to pretreat patients with prior documentation of minor allergic reactions. Antihistamines are used for premedication to antivenom administration to reduce acute adverse reactions (not for direct treatment of snakebite).

FOLLOW-UP

Section 8 of 11  

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Further Inpatient Care

• Admit
• • Strongly consider admission for all Mohave rattlesnake envenomations. Because patients with severe Mohave envenomation may present with only minimal local tissue effects, underestimation of a significant injury can easily occur. Because of the relative infrequency of the injury, admitting all patients with suspected Mohave rattlesnake envenomations is probably prudent and cost effective.
  • Effects of Mohave rattlesnake envenomation may be prolonged and have been shown to improve with late administration of antivenom.
  • Anaphylaxis

Further Outpatient Care

• Discharge instructions should include the following:
• • Return immediately if swelling worsens or pain becomes severe.
  • Return immediately if any abnormal bleeding or bruising, dark tarry stools, or severe headache occur.
  • Return for signs of wound infection, such as swelling, excessive tenderness, redness or streaks, heat, or drainage (pus).
  • Return or follow up if a fever, itchy rash, joint pain, or swollen lymph nodes occur any time during the next few weeks.
  • Do not take nonsteroidal anti-inflammatory drugs (NSAIDS), such as aspirin, ibuprofen (Motrin, Advil), or naproxen (Naprosyn, Aleve) for 2 weeks after the snakebite. Acetaminophen (Tylenol) or a prescribed pain medication can be taken.
  • Do not participate in contact sports, undergo elective surgery, or have dental work for 2 weeks after the snakebite.
  • Drink plenty of liquids. Return if urine decreases in amount or becomes cola colored.
  • Referral to a physical therapist or surgeon may be indicated.
  • Wound check at the physician's discretion on a case-by-case basis. Return to the ED or follow up every 3 days for 2 weeks with repeat CBC, PT/INR, and fibrinogen. Laboratory studies may need to be rechecked more or less frequently or for a longer or shorter duration on a case-by-case basis.

In/Out Patient Meds

• Administer antihistamines and steroids if serum sickness develops.

Transfer

• All hospitals should have enough antivenom to treat at least one patient. However, antidote stocking varies and shortages do occur. Therefore, if antivenom is not available at the presenting hospital, patients should be transferred to a facility where antivenom may be administered. However, if it is available, antivenom may be necessary to optimize stabilization of a patient prior to transfer.

Deterrence/Prevention

• Never handle a rattlesnake, even if it is believed to be dead. Serious, even fatal, envenomations have been documented to occur after handling the decapitated head of a rattlesnake up to 90 minutes after it was severed.
• Do not reach or step into places outdoors that are not visible.
• At home, remove debris in which snakes might hide (eg, log piles). Remove items, such as bird feeders, that might attract snakes—seeds that fall from bird feeders attract rodents, which attract snakes.
• Heavy clothing (such as hiking boots) may retard some strikes.
• Young children should be closely supervised, and older children should be educated to avoid snakes.
• Keep garage doors closed to prevent rattlesnakes from seeking shelter in garages.

Complications

• Rhabdomyolysis
• Infection
• Respiratory difficulty
• Death (rare)
• Antivenom-associated complications:
• • Anaphylaxis is a type I (immediate) hypersensitivity reaction that may be life threatening. It is characterized by urticaria, wheezing laryngeal edema, and shock. Some degree of anaphylaxis may occur in as many as 25% of patients given Antivenin (Crotalidae) Polyvalent. Risk factors include previous exposure to horse serum or antivenom or a history of reactive airways. Anaphylaxis is treated with epinephrine, antihistamines, steroids, and ventilatory/circulatory support. Although experience is limited, immediate hypersensitivity is less common after treatment with CroFab.
  • Serum sickness is a type III (delayed) hypersensitivity reaction. It is characterized by fever, urticaria, lymphadenopathy, and arthritis and may occur 5 days to 3 weeks after Antivenin (Crotalidae) Polyvalent administration in as many as 50% of patients. Serum sickness is dose related and almost always occurs when more than 8 vials of antivenin (Crotalidae) polyvalent are administered. Although serum sickness can be an uncomfortable experience, it is usually benign and self-limited and is treated with steroids and antihistamines. Delayed hypersensitivity is much less common after treatment with CroFab, although experience with this relatively new medication is limited.

Prognosis

• Full recovery is usually anticipated.
• Before antivenom, estimates of mortality rates ranged from 5-25%.
• Because of the development of antivenom, rapid EMS transport, and emergency/intensive care, mortality rates have improved to 0.28% (or better) when antivenom is administered and to 2.6% when antivenom is not administered.

Patient Education

• Call professionals, such as animal control, to move snakes (if it is necessary to move the snake).
• Never attempt to handle, possess, or kill venomous reptiles.
• For patient education resources, visit eMedicine's Bites and Stings Center. Also, see eMedicine's patient education article Snakebite.

MISCELLANEOUS

Section 9 of 11  

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• Clinical
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• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Medical/Legal Pitfalls

• Medicolegal problems may occur when a patient is sent home with a diagnosis of mild or no envenomation but subsequently returns with significant envenomation and requires antivenom and/or admission.
• Discharging patients too quickly has particular pertinence in Mohave rattlesnake envenomations, in which severe envenomation may occur with little or no local tissue effects.
• Failure to treat with antivenom, when indicated, is a pitfall.
• Delays from the time the patient seeks medical care and the time the patient is treated are often cited in litigation.
• If possible, obtain informed consent before administering antivenom.
• Inform the patient that loss of tissue or function may result from rattlesnake envenomation and that antivenom and/or surgery may not prevent it.

Special Concerns

• Mohave rattlesnake (C scutulatus) envenomation is among the most controversial topics in envenomation medicine.
• • Presentation is extremely variable, and few reports of clinical effects of envenomation exist.
  • Generally, envenomation is an uncommon occurrence with an extremely variable presentation, ranging from no ill effects to multisystem failure and death.
  • Treatment of envenomation often is based on speculation and anecdote, and much of the literature is contradictory.
  • The authors have attempted to keep recommendations in agreement with the most current standards of care.
  • These are guidelines, and the clinician should use judgment for individual patient encounters.

MULTIMEDIA

Section 10 of 11  

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• Differentials
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• Follow-up
• Miscellaneous
• Multimedia
• References

Media file 1:  Mohave rattlesnake (Crotalus scutulatus). Note the diamond pattern fades into bands along the caudal third of the back and the white tail rings are wider than the black. Photo by Sean Bush, MD.
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Media file 2:  This is the typical appearance of a southern California Mohave rattlesnake bite site. Photo by Sean Bush, MD.
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Media file 3:  Mohave rattlesnake (Crotalus scutulatus). Photo by Sean Bush, MD.
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Media file 4:  A red diamond rattlesnake (Crotalus ruber). The postocular light stripe extends above the angle of the mouth in Mohave rattlesnakes. Photo by Sean Bush, MD.
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Media file 5:  This is a juvenile Mohave rattlesnake (postmortem). Note that the diamondback pattern fades into bands along the latter part of the snake`s dorsum. Photo by Sean Bush, MD.
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Media file 6:  A western diamondback rattlesnake (Crotalus atrox). Photo by Sean Bush, MD.
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REFERENCES

Section 11 of 11

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

• Bush SP, Jansen PW. Severe rattlesnake envenomation with anaphylaxis and rhabdomyolysis. Ann Emerg Med. Jun 1995;25(6):845-8. [Medline].
• Bush SP, Cardwell MD. Mojave rattlesnake (Crotalus scutulatus scutulatus) identification. Wilderness Environ Med. Spring 1999;10(1):6-9. [Medline].
• Bush SP, Hegewald KG, Green SM, et al. Effects of a negative pressure venom extraction device (Extractor) on local tissue injury after artificial rattlesnake envenomation in a porcine model. Wilderness Environ Med. Fall 2000;11(3):180-8. [Medline].
• Bush SP, Green SM, Laack TA, et al. Pressure immobilization delays mortality and increases intracompartmental pressure after artificial intramuscular rattlesnake envenomation in a porcine model. Ann Emerg Med. Dec 2004;44(6):599-604. [Medline].
• Bush SP, Green SM, Moynihan JA, et al. Crotalidae polyvalent immune Fab (ovine) antivenom is efficacious for envenomations by Southern Pacific rattlesnakes (Crotalus helleri). Ann Emerg Med. Dec 2002;40(6):619-24. [Medline].
• Bush SP. Snakebite suction devices don't remove venom: they just suck. Ann Emerg Med. Feb 2004;43(2):187-8. [Medline].
• Carroll RR, Hall EL, Kitchens CS. Canebrake rattlesnake envenomation. Ann Emerg Med. Jul 1997;30(1):45-8. [Medline].
• Clark RF, Williams SR, Nordt SP, Boyer-Hassen LV. Successful treatment of crotalid-induced neurotoxicity with a new polyspecific crotalid Fab antivenom. Ann Emerg Med. Jul 1997;30(1):54-7. [Medline].
• Farstad D, Thomas T, Chow T, et al. Mojave rattlesnake envenomation in southern California: a review of suspected cases. Wilderness Environ Med. May 1997;8(2):89-93. [Medline].
• French WJ, Hayes WK, Bush SP. Mojave toxin in venom of Crotalus helleri (Southern Pacific Rattlesnake): molecular and geographic characterization. Toxicon. Dec 1 2004;44(7):781-91. [Medline].
• Glenn JL, Straight RC. Intergradation of two different venom populations of the Mojave rattlesnake (Crotalus scutulatus scutulatus) in Arizona. Toxicon. 1989;27(4):411-8. [Medline].
• Hardy DL. Fatal rattlesnake envenomation in Arizona: 1969-1984. J Toxicol Clin Toxicol. 1986;24(1):1-10. [Medline].
• Hardy DL. Envenomation by the Mojave rattlesnake (Crotalus scutulatus scutulatus) in southern Arizona, U.S.A. Toxicon. 1983;21(1):111-8. [Medline].
• Jansen PW, Perkin RM, Van Stralen D. Mojave rattlesnake envenomation: prolonged neurotoxicity and rhabdomyolysis. Ann Emerg Med. Mar 1992;21(3):322-5. [Medline].
• Wingert WA, Chan L. Rattlesnake bites in southern California and rationale for recommended treatment. West J Med. Jan 1988;148(1):37-44. [Medline].

Article Last Updated: May 24, 2006