How do you identify a coral snake. What are the symptoms of a coral snake bite. What is the proper treatment for a coral snake envenomation. Why are coral snake bites so dangerous. How effective is antivenom for coral snake bites. What should you do if bitten by a coral snake.

Coral Snake Identification: The Key to Prevention

Coral snakes are known for their distinctive colorful banding, but identifying them correctly can be a matter of life and death. The old rhyme “Red touch yellow, kills a fellow; red touch black, venom lack” has long been used to distinguish venomous coral snakes from their harmless lookalikes. However, it’s crucial to note that this rule only applies to native North American species.

There are three species of coral snakes found in the United States:

• Eastern coral snake (Micrurus fulvius) – Found in Florida and the southeastern US
• Texas coral snake (Micrurus tener) – Found in Texas and northwestern Mexico
• Arizona or Sonoran coral snake (Micruroides euryxanthus) – Found in southeastern US and Sonora, Mexico

While coral snakes are generally reclusive and rarely bite unless provoked, it’s essential to be able to identify them accurately to prevent potential envenomation.

Can you rely on color patterns alone to identify a coral snake?

While the color pattern is a useful guide, it’s not foolproof. Some non-venomous snakes, such as the scarlet kingsnake, can have similar patterns. Additionally, coral snakes in other parts of the world may have different color patterns. Therefore, it’s always best to avoid handling any snake you can’t identify with absolute certainty.

The Nature of Coral Snake Bites: Understanding the Risk

Coral snake bites are relatively rare, accounting for only about 2% of snake bites reported to US Poison Centers annually. This low incidence is primarily due to the snake’s reclusive nature and reluctance to bite unless threatened. However, when a bite does occur, it can be extremely dangerous, particularly in the case of the Eastern coral snake.

Unlike pit vipers such as rattlesnakes, coral snakes have small, fixed fangs. When they bite, they tend to latch onto their prey and “chew” for a few seconds to deliver their venom. This method of envenomation can sometimes result in bite marks that are easily missed, with no significant local tissue damage, obvious injury, or immediate pain.

Are all coral snake bites equally dangerous?

Not all coral snake bites are equally severe. Bites from the Eastern coral snake tend to be the most dangerous, while those from the Arizona/Sonoran and Texas coral snakes are generally not associated with serious side effects or death. However, any suspected coral snake bite should be treated as a medical emergency due to the potential for severe complications.

The Venom Factor: Why Coral Snake Bites Are So Dangerous

The venom of coral snakes, particularly the Eastern species, contains potent neurotoxins that can cause severe illness or death if left untreated. These neurotoxins work by blocking acetylcholine, a crucial neurotransmitter responsible for muscle activation in the body.

When acetylcholine is blocked due to envenomation, it can lead to a cascade of serious symptoms, including:

• Weakness
• Paralysis
• Complete respiratory failure in severe cases

One of the most insidious aspects of coral snake envenomation is the delayed onset of symptoms, which can take up to 13 hours to manifest. However, once symptoms begin to appear, they can progress rapidly, making immediate medical attention crucial.

How does coral snake venom differ from other snake venoms?

Coral snake venom is primarily neurotoxic, affecting the nervous system, unlike the hemotoxic venom of many pit vipers that primarily affects blood and tissue. This difference in venom composition results in distinct symptoms and requires specific treatment approaches.

Recognizing the Symptoms: Early Warning Signs of Coral Snake Envenomation

Given the potential severity of coral snake bites, it’s crucial to be aware of the symptoms that may indicate envenomation. These can include:

1. Nausea and vomiting
2. Paresthesias (abnormal sensations)
3. Slurred speech
4. Double vision
5. Ptosis (drooping eye)
6. Muscle twitching
7. Weakness
8. Paralysis

It’s important to note that these symptoms may not appear immediately after the bite. The delay in symptom onset can be misleading, potentially causing victims to underestimate the severity of their condition.

Can coral snake bite symptoms be mistaken for other conditions?

The neurological symptoms of a coral snake bite can sometimes be mistaken for other conditions, such as stroke or Guillain-Barré syndrome. This is why it’s crucial to inform healthcare providers of any potential snake exposure, even if it occurred hours before symptoms appeared.

Emergency Response: Immediate Actions Following a Coral Snake Bite

If you or someone you know has been bitten by a coral snake, immediate action is crucial. Here are the steps you should take:

1. Seek medical attention immediately by calling 911 or your local emergency number.
2. Keep the victim calm and still to slow the spread of venom.
3. Remove any constricting items like jewelry or tight clothing.
4. Position the affected limb below the heart to slow venom spread.
5. Clean the wound, but do not attempt to suck out the venom or apply a tourniquet.
6. If possible, safely capture or photograph the snake for identification purposes.

Remember, all suspected coral snake bites should be treated as medical emergencies, even if symptoms are not immediately apparent.

Is it safe to attempt capturing the snake for identification?

While identification of the snake can be helpful for treatment, attempting to capture a venomous snake is extremely dangerous and not recommended. If it can be done safely, such as taking a photograph from a distance, this can be helpful. However, your primary focus should be on seeking immediate medical attention.

Medical Treatment: The Challenges of Coral Snake Envenomation

The traditional treatment for coral snake envenomation has been the North American Coral Snake Antivenin, a horse-derived IgG antibody antivenom. However, production of this antivenom ceased in 2006, creating significant challenges in treatment.

Currently, healthcare providers face several obstacles in treating coral snake bites:

• Limited availability of antivenom
• Use of expired antivenom (with FDA-approved extensions)
• Need for careful risk/benefit assessment before administering antivenom
• Reliance on supportive care when antivenom is unavailable

Given these challenges, management of coral snake bites often requires close collaboration between healthcare providers, Poison Control Centers, and toxicologists to provide optimal care for each patient.

What happens if antivenom is not available?

In cases where antivenom is unavailable, treatment focuses on supportive care. This primarily involves managing the patient’s airway, potentially including mechanical ventilation if respiratory failure occurs. Other treatments, such as the anticholinesterase drug neostigmine, have shown potential benefits in some cases, but data on their efficacy is limited and inconsistent.

The Role of Poison Control Centers in Coral Snake Bite Management

Poison Control Centers play a crucial role in the management of coral snake bites. These centers can provide valuable assistance in several ways:

1. Offering immediate guidance on initial care and whether to seek medical attention
2. Helping healthcare providers locate available antivenom
3. Providing expert consultation on treatment strategies
4. Assisting in the coordination of care between different medical facilities
5. Collecting data on coral snake bites to improve future treatment protocols

If you suspect a coral snake bite, don’t hesitate to contact Poison Control at 1-800-222-1222 or use the webPOISONCONTROL® online tool for guidance.

How can Poison Control Centers help in areas where coral snakes are not native?

Even in areas where coral snakes are not native, Poison Control Centers can provide crucial assistance. They can help identify potential exotic pet exposures, provide guidance on general snake bite management, and connect local healthcare providers with experts in coral snake envenomation.

Prevention Strategies: Minimizing the Risk of Coral Snake Encounters

While coral snake bites are rare, prevention is always the best strategy. Here are some tips to minimize your risk of encountering a coral snake:

• Be cautious when walking in areas where coral snakes are known to live, especially during warmer months when snakes are more active.
• Wear closed-toe shoes and long pants when walking in tall grass or wooded areas.
• Avoid reaching into dark spaces, such as under rocks or logs, without first checking for snakes.
• Use a flashlight when walking outdoors at night in snake-prone areas.
• Keep your yard free of debris and tall grass that could attract snakes.
• Educate children about the dangers of handling snakes and the importance of leaving wild animals alone.

Remember, coral snakes are generally not aggressive and will usually try to avoid human contact. Most bites occur when the snake is accidentally stepped on or when someone attempts to handle the snake.

Do coral snakes pose a significant threat to pets?

While coral snakes can pose a threat to pets, especially curious dogs, bites are relatively rare. However, if a pet is bitten by a coral snake, it should be treated as a medical emergency and veterinary care should be sought immediately. The same antivenom used for humans can be used to treat pets, although availability may be limited.

Future Outlook: Advancements in Coral Snake Bite Treatment

The field of snake bite treatment is continually evolving, with researchers working on new and improved antivenoms and alternative treatments. Some promising developments include:

• Development of new coral snake antivenoms with fewer side effects
• Research into small molecule inhibitors that could neutralize snake venom
• Exploration of synthetic antibodies as a potential treatment option
• Improved point-of-care diagnostics for faster and more accurate bite assessment
• Development of universal antivenoms that could treat bites from multiple snake species

While these advancements offer hope for improved treatment options in the future, they also underscore the importance of ongoing research and funding in this critical area of medical care.

How might advances in antivenom production impact coral snake bite treatment?

Advances in antivenom production could potentially lead to more readily available and safer treatments for coral snake bites. New production methods, such as recombinant DNA technology, could allow for the creation of antivenoms that are more specific, have fewer side effects, and can be produced more efficiently. This could greatly improve the prognosis for coral snake bite victims, especially in areas where current antivenoms are in short supply.

In conclusion, while coral snake bites are rare, they pose a significant medical risk due to the potent neurotoxins in their venom. Proper identification, immediate medical attention, and appropriate treatment are crucial for managing these potentially life-threatening envenomations. As research continues and new treatments emerge, the outlook for coral snake bite victims may improve. However, prevention remains the best strategy, emphasizing the importance of education and awareness in areas where these elusive but dangerous snakes reside.

Coral Snake Bite Treatment | Poison Control

The Full Story

“Red touch yellow, kills a fellow; red touch black, venom lack.“ Of all the childhood rhymes we’ve grown up learning, this one might be high on the list of ones to remember if you live in coral snake country. If you aren’t familiar with this saying, it refers to distinguishing the venomous coral snake from its nonvenomous look-alikes (e.g., the king snake, shovel-nosed snake, and milk snake). It’s important to note that this general rule doesn’t apply to non-native coral snake species, which might have different patterns. Coral snakes are members of the Elapidae family, which includes cobras. Coral snakes usually have a pattern of red, black, yellow (or white) colored rings that span their bodies. For the purposes of this article, we’ll focus primarily on the three species found in the US, which are:

• Eastern coral snake (Micrurus fulvius) – Found in Florida and the southeastern US
• Texas coral snake (Micrurus tener) – Found in Texas and northwestern Mexico
• Arizona or Sonoran coral snake (Micruroides euryxanthus) – Found in southeastern US, and Sonora, Mexico)

By nature, coral snakes are reclusive and seldom bite unless they’re provoked or threatened. Compared to their pit viper counterparts (e.g., rattlesnakes), coral snake bites are uncommon and represent only about 2% of snake bites reported to US Poison Centers annually. Of the three species in the US, bites by the eastern coral snake tend to be the most severe, while those of the Arizona/Sonoran and Texas coral snakes aren’t generally associated with serious side effects or death. 

Coral snakes have small, fixed fangs, and when they bite they tend to latch onto their prey and “chew” for a few seconds in order to deliver their venom. Compared to other venomous snakes, their bite marks can be easily missed, often showing no significant local tissue damage, obvious injury, or pain. However, the venom of the Eastern coral snake contains very potent neurotoxins that can cause severe illness or death if left untreated. The neurotoxic venom blocks an important neurotransmitter called acetylcholine, which is important for the activation of muscles in the body. Blockade of acetylcholine after envenomation can lead to weakness and paralysis and even complete respiratory failure in severe cases. The effects of the venom are usually delayed (up to 13 hr) but progress rapidly once they develop. Symptoms of a coral snake envenomation can include nausea, vomiting, paresthesias (abnormal sensations), slurred speech, double vision, ptosis (drooping eye), muscle twitching, weakness, and paralysis. The major cause of death from coral snake envenomations is respiratory failure as a result of neuromuscular weakness.

Given the potentially serious outcomes after a coral snake bite, all people with a suspected envenomation should be seen in a hospital immediately and observed for at least 24 hours. The traditional treatment for coral snake envenomation has been a horse-derived IgG antibody antivenom produced by Wyeth Pharmaceuticals (now a subsidiary of Pfizer, Inc.) called the North American Coral Snake Antivenin. However, the manufacturer stopped production in 2006. The remaining available antivenom has passed the manufacturer-assigned expiration date of 2008, but FDA continues to provide information on expiration date extensions based evaluation of stability data. Because having a supply of the antivenom is uncommon in most hospitals, healthcare providers need to work with their regional Poison Control Center to locate a source of supply. If the antivenom is available, if and when to start is decided on a case-by-case basis after careful risk/benefit assessment as antivenom administration is not without dangers. If the antivenom is unavailable, management of the patient is focused on supportive care, which includes airway management with mechanical ventilation. There are other treatment options that have been shown to possibly provide benefit for certain coral snake bites, like the anticholinesterase drug neostigmine. However, data on its efficacy is limited and inconsistent. In all cases, discussion among the healthcare providers, Poison Control Centers, and toxicologists is key to providing optimal care for each patient.

If you or someone you know has been bitten by a coral snake, seek medical attention by calling 911 or Poison Control (1-800-222-1222), or use the webPOISONCONTROL^{® online tool for guidance.}

Kristina Yee, PharmD
Certified Specialist in Poison Information

Poisoned?

Call


1-800-222-1222


or

HELP ME online

Prevention Tips

• Coral snakes aren’t usually aggressive unless they feel threatened or are provoked. If you come across one, leave it alone!
• If someone has been bitten by a coral snake, seek medical evaluation immediately. Do NOT wrap the area in a tourniquet, cut the wound, or attempt to “suck the venom out.” None of these are helpful and can potentially make things worse.

This Really Happened

Case 1. A 9-year-old boy was bitten on the right index finger after a coral snake was thrown at him. He reported local and radiating pain at the bite site as well as abdominal pain. One hour after the incident, he was taken to a hospital and received 5 vials of antivenom. He was observed in the ICU and only developed mild local swelling. He was discharged after 3 days in the hospital.

Case 2. A 15-year-old girl was bitten on her arm by an exotic coral snake. She was taken to a hospital and observed in the ICU. She was not treated with antivenom due to its unavailability. Her only reported symptoms were vomiting and swelling, and she was discharged after 3 days in the hospital.

Case 3. A 6-year-old boy was bitten while catching a coral snake. He developed anaphylaxis during antivenom administration. Nine hours after the bite he had drooling and difficulty swallowing and required mechanical ventilation for 8 days. He was discharged after 16 days in the hospital.

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For More Information

Expiration date extension for North American coral snake antivenin (Micurus fulvius) (equine origin) lot L67530 through January 32, 2020. Silver Spring (MD): US Food and Drug Administration; 2019 Feb 1 [cited 2020 Aug 31].

Sartore J. Eastern coral snake [photo].Washington: National Geographic Society [cited 2020 Aug 31].

References

Corbett B, Clark RF. North American snake envenomation. Emerg Med Clin North Am. 2017 May;35(2):339-54.

Expiration date extension for North American coral snake antivenin (Micurus fulvius) (equine origin) lot L67530 through January 32, 2020. Silver Spring (MD): US Food and Drug Administration; 2019 Feb 1 [cited 2020 Aug 31].

Hessel MM, Sauerberg N, McAninch SA. Coral snake toxicity. Treasure Island (FL): StatPearls Publishing; 2020 Apr 23 [cited 2020 Aug 31].

Hoffman, RS, Howland, MA, Lewin, NA, Nelson, LS, Goldfrank, LR, editors. Goldfrank’s toxicologic emergencies. 10th ed. New York: McGraw Hill; c2015. Chapter 122, Native (US) venomous snakes and lizards.

McAninch SA, Morrissey RP, Rosen P, Meyer TA, Hessel MM, Vohra MH. Snake Eyes: Coral Snake Neurotoxicity Associated With Ocular Absorption of Venom and Successful Treatment With Exotic Antivenom. J Emerg Med. 2019 May;56(5):519-522.

Pawar DK, Singh H. Elapid snake bite. Br J Anaesth. 1987 Mar;59(3):385-7. 

Peterson ME. Snake bite: coral snakes. Clin Tech Small Anim Pract. 2006 Nov;21(4):183-6. 

Sánchez EE, Lopez-Johnston JC, Rodríguez-Acosta A, Pérez JC. Neutralization of two North American coral snake venoms with United States and Mexican antivenoms. Toxicon. 2008 Feb;51(2):297-303.

Sasaki J, Khalil PA, Chegondi M, Brzezinski A, Meyer KG, et al. Coral snake bites and envenomation in children: a case series. Pediatr Emerg Care. 2014 Apr;30(4):262-5.

Wood A, Schauben J, Thundiyil J, Kunisaki T, Sollee D, et al. Review of eastern coral snake (Micrurus fulvius fulvius) exposures managed by the Florida Poison Information Center Network: 1998-2010. Clin Toxicol (Phila). 2013 Sep-Oct;51(8):783-8.

Poisoned?

Call


1-800-222-1222


or

HELP ME online

Prevention Tips

• Coral snakes aren’t usually aggressive unless they feel threatened or are provoked. If you come across one, leave it alone!
• If someone has been bitten by a coral snake, seek medical evaluation immediately. Do NOT wrap the area in a tourniquet, cut the wound, or attempt to “suck the venom out.” None of these are helpful and can potentially make things worse.

This Really Happened

Case 1. A 9-year-old boy was bitten on the right index finger after a coral snake was thrown at him. He reported local and radiating pain at the bite site as well as abdominal pain. One hour after the incident, he was taken to a hospital and received 5 vials of antivenom. He was observed in the ICU and only developed mild local swelling. He was discharged after 3 days in the hospital.

Case 2. A 15-year-old girl was bitten on her arm by an exotic coral snake. She was taken to a hospital and observed in the ICU. She was not treated with antivenom due to its unavailability. Her only reported symptoms were vomiting and swelling, and she was discharged after 3 days in the hospital.

Case 3. A 6-year-old boy was bitten while catching a coral snake. He developed anaphylaxis during antivenom administration. Nine hours after the bite he had drooling and difficulty swallowing and required mechanical ventilation for 8 days. He was discharged after 16 days in the hospital.

Coral Snake Toxicity – StatPearls

Continuing Education Activity

Coral snakes are members of the Elapidae family, and 40 to 50 species exist in the Americas. In the United States, three types predominate: Micrurus fulvius (eastern coral snake, located in Florida and the southeast US) and Micrurus tener (Texas coral snake, located in Texas and Northwestern Mexico), and Micruroides euryxanthus (Sonoran coral snake, located in the Southeastern US and the state of Sonora, Mexico) inhabit the US. Coral snakes in North America (north of Mexico City) are recognized by their circumferential bands (non-circumferential shape is found on the non-venomous shovel-nosed snake) of red, yellow, and black. This activity reviews coral snake toxicity, its presentation, and highlights the role of the interprofessional team in its management.

Objectives:

• Describe the pathophysiology of coral snake toxicity.

• Describe the presentation of a patient with coral snake toxicity.

• Summarize the treatment options for coral snake toxicity.

• Review the importance of improving care coordination among interprofessional team members to improve outcomes for patients affected by coral snake toxicity.

Access free multiple choice questions on this topic.

Introduction

Coral snakes are members of the Elapidae family, and 40 to 50 species exist in the Americas. In the United States, three types predominate: Micrurus fulvius (eastern coral snake, located in Florida and the southeast US) and Micrurus tener (Texas coral snake, located in Texas and Northwestern Mexico), and Micruroides euryxanthus (Sonoran coral snake, located in the Southeastern US and the state of Sonora, Mexico) inhabit the US.  [1] Coral snakes in North America (north of Mexico City) are recognized by their circumferential bands (non-circumferential shape is found on the non-venomous shovel-nosed snake) of red, yellow, and black (figure 1). In North American snakes only, the color sequence may distinguish the venomous coral snake from non-venomous snakes, such as the king snake, whose pattern is “red on black,” and is demonstrated by the mnemonic “red on yellow, kills a fellow; red on black, venom lack.” Coral snake envenomations are relatively uncommon compared to their pit viper counterparts. However, coral snake venom is very potent and may result in a delayed onset of significant neurotoxicity and respiratory failure. [2]

Etiology

The venom of M. fulvius and M. tener is a highly potent neurotoxin. M. euryxanthus envenomation is not known to cause significant symptoms in humans, although this species does boast a protective sonic warning capability called a “microfart” (caused by air expulsion from its cloaca). The incidence of significant coral snake envenomation is less than that of pit viper bites for several reasons. Unlike pit vipers, coral snakes are more elusive and will often retreat from any signs of danger rather than confront any potential threats. Hence, coral snake bites commonly occur after intentional handling of the snake by humans or from harassment by curious animals. 

Epidemiology

Only 25 to 50 of the approximately 9000 total snake bites in the US are due to coral snakes. Micrurus fulvius and Micrurus tener account for all clinically significant coral snake bites reported in the US. Only one death due to coral snake envenomation has been reported in North America in the recent past. [3]

Pathophysiology

Unlike pit vipers, whose venom causes local tissue necrosis and coagulopathy, coral snake venom gains systemic access through the lymphatic veins to cause neurotoxicity and respiratory muscle weakness using competitive inhibition of the nicotinic acetylcholine receptors at the neuromuscular junction.  [4]

Toxicokinetics

Both pre-synaptic and post-synaptic inhibition (by alpha neurotoxins) have been documented. Additionally, phospholipase A2 may cause myotoxicity and rhabdomyolysis. [5]

History and Physical

When a victim presents with a reported coral snake bite or mucous membrane exposure to its venom, it is important to determine when the bite occurred as neurotoxic effects and respiratory insufficiency may be delayed up to 13 hours. [6] If possible, the identity of the snake should be verified through photographic images. Initial presenting symptoms may include mild pain at the bite site (no puncture marks may be present), nausea, vomiting, dizziness, and abdominal pain. Neurotoxicity may present with progressive motor deficits including cranial nerve deficits, such as ptosis, dysarthria, and dysphagia as well as descending muscle weakness. Importantly, patients should be closely monitored for signs of respiratory muscle weakness with pulmonary insufficiency; this is the most life-threatening complication of coral snake envenomation.

Evaluation

Evaluation of coral snake envenomation victims should focus on assessment of the development of neurologic deficits and respiratory compromise. [7] Serial pulmonary function testing is helpful to predict respiratory insufficiency. Respiratory compromise is suggested by an FVC (forced vital capacity) less than 50% predicted, MIP (maximal inspiratory pressure) less negative than -30 cmh3O, or an MEP (maximal expiratory pressure) below 40 cmh30. Additionally, declines in mental status, bedside capnography (ETC02), and blood gas measurements may be used to monitor for hypercarbia or respiratory acidosis that may indicate impending respiratory failure. Rhabdomyolysis may occur in M. fulvius envenomation and should be evaluated as clinical scenario warrants. Unlike pit viper envenomation victims, significant bite area tissue necrosis and coagulopathies are uncommon in coral snake envenomation.

Treatment / Management

General treatment measures include ensuring a safe scene (remove from snake exposure), local wound care (although wounds are typically minimal), minimization of movement (relative immobilization in a functional position), avoiding activities that increase heart rate, and promoting patient (and family) relaxation (to decrease systemic propagation of venom). Tetanus prophylaxis is also considered standard in the treatment of snakebites. Pressure immobilization bandages [8] may be placed over the bite site with just enough force to allow arterial and venous flow but decrease lymphatic flow, potentially decreasing the systemic absorption of coral snake venom through lymphatics. [9] Tourniquets, venom extraction (either by incision and oral suction, manually or by a mechanical device), and cryotherapy are not recommended. If possible, avoid medications that may cause muscle weakness or decreased respiratory function, as these may inhibit the ability to assess for neurotoxic effects due to envenomation.

Due to the possibility of the delayed onset of life-threatening respiratory compromise, all patients with suspected coral snake envenomation warrant close observation for at least 24 hours at an appropriate level of care for close respiratory monitoring and frequent serial neurologic exams. Patients who demonstrate respiratory insufficiency warrant advanced airway management and treatment with coral snake antivenom and/or other pharmacologic measures, such as anticholinesterases (discussed below). Airway compromise may develop rapidly, so advanced airway medications and equipment should be prepared early and readily available. 

The North American Coral Snake Antivenin (NACSA) is a horse-derived IgG antibody used for both M. fulvius and M. tener envenomation in both adults and children. Its use has not been reported in patients who are pregnant. The administration of coral snake antivenom is recommended at the first sign of neurologic deficit or respiratory insufficiency, as some data suggest decreased need for intubation or decreased duration of muscle paralysis and intubation. On the other hand, other data suggest no differences in intubation rates when NACSA is given prophylactically before symptom onset. So, should practitioners administer NACSA empirically to patients without neurologic deficits or respiratory compromise? This is a controversial decision, but given the additional risk of immediate and delayed hypersensitivity reactions (discussed below) and mixed clinical evidence results regarding prophylactic antivenom benefit, it is reasonable to procure antivenom early but withhold administration until the development of the first neurologic symptoms.  In any case, the best course of action is to contact the Poison Control Center or a toxicologist for treatment guidance. Currently, there is a limited supply of the NACSA, as production ceased in 2006. The known remaining vials of this antivenom have passed the manufacturer’s expiration date (2008), but the FDA extended the expiration date through January 31, 2019, for NACSA Lot L67530.[10] If treatment with antivenom is indicated, contact the Poison Control Center (1-800-222-1222) or a toxicologist for the acquisition of the antivenom and further recommendations. Also, the FDA Office of Vaccines, Blood, and Biologics (301-827-3524) may be contacted for information regarding the risks and benefits of administering expired antivenom. Moreover, it is recommended to contact Poison Control early to assist with the location and mobilization of NACSA, as significant time and mobilization resources may be required to procure it. [11] Once the decision is made to administer NACSA, the patient undergoes a test dose of the included horse serum for reactions, and after that, the recommended initial dose of NACSA is three to five vials by slow intravenous push for both adults and pediatrics. Of note, a potential new coral snake antivenom, an equine-based F(ab’), is currently in clinical trials in the US. Other antivenoms useful for coral snakes may be available (such as Coralmyn, manufactured in Mexico) and recommended by Poison Control. [12]

As discussed earlier, NACSA is an equine-based IgG serum, and there is a risk of both immediate and delayed hypersensitivity reactions. [13] When giving NACSA, clinicians should watch for signs of hives, itching, shortness of breath, hypotension, or angioedema as evidence of an allergic reaction. If patients demonstrate signs of an immediate hypersensitivity reaction, infusion of the antivenom should be stopped immediately, and doses of epinephrine IM (0.3 mg if greater than 30kg, 0.15mg if less than 30 kg of the 1:1000 concentration), antihistamine, corticosteroids, and albuterol nebulizers should be given as needed based on clinical symptoms.

If the patient develops neurotoxicity or respiratory compromise and coral snake antivenom is not available, another pharmacologic treatment option is a trial dose of an anticholinesterase, such as neostigmine. Neostigmine acts by restoring neuromuscular transmission by increasing concentrations of acetylcholine in the neuromuscular junction when weakness is due to the post-synaptic blockade. Pretreatment with atropine or glycopyrrolate should be considered to prevent potential excessive cholinergic effects of neostigmine. Again, poison control and toxicologist consultation are recommended to guide treatment. 

Differential Diagnosis

• Anaphylaxis

• Septic shock

• Serum sickness

• Wasp stings

• Wound care

• Wound infections

Pearls and Other Issues

• Coral snake venom acts by inhibiting acetylcholine receptors at the neuromuscular junction to cause neurotoxic motor weakness.

• Life-threatening complications of coral snake bites are related to respiratory muscle weakness and the need for ventilatory support.

• Although significant envenomation is uncommon due to the coral snake’s less-aggressive behavior and difficult mechanism of delivery, the potential of life-threatening respiratory insufficiency delay of up to 13 hours warrants very close observation after a reported exposure.

• While limited in supply and difficult to obtain and transport, coral snake antivenom should be given to all patients bitten by coral snakes regardless of symptoms.

• Hypersensitivity reactions to equine-based coral snake antivenom are common, and infusion should be stopped immediately if patients develop adverse reactions.

Enhancing Healthcare Team Outcomes

The management of coral snake bites is with an interprofessional team that consists of an emergency department physician, poison control, internist, intensivist, toxicologist, and ICU nurses. These patients need admission and close monitoring as life-threatening complications of coral snake bites are related to respiratory muscle weakness and the need for ventilatory support. Although significant envenomation is uncommon due to the coral snake’s less-aggressive behavior and difficult mechanism of delivery, the potential of life-threatening respiratory insufficiency delay of up to 13 hours warrants very close observation after a reported exposure. While limited in supply and difficult to obtain and transport, coral snake antivenom should be given to all patients bitten by coral snakes regardless of symptoms. The outcomes in patients treated with antivenom are excellent but if there is a delay in treatment, then fatalities are known to occur. [3][14][Level 5]

Review Questions

• Access free multiple choice questions on this topic.

• Comment on this article.

Figure

Coral Snake. Contributed by The CDC / Edward J. Wozniak D.V.M., Ph.D.

References

1.

Yang DC, Dobson J, Cochran C, Dashevsky D, Arbuckle K, Benard M, Boyer L, Alagón A, Hendrikx I, Hodgson WC, Fry BG. The Bold and the Beautiful: a Neurotoxicity Comparison of New World Coral Snakes in the Micruroides and Micrurus Genera and Relative Neutralization by Antivenom. Neurotox Res. 2017 Oct;32(3):487-495. [PubMed: 28674788]

2.

Vergara I, Castillo EY, Romero-Piña ME, Torres-Viquez I, Paniagua D, Boyer LV, Alagón A, Medina LA. Biodistribution and Lymphatic Tracking of the Main Neurotoxin of Micrurus fulvius Venom by Molecular Imaging. Toxins (Basel). 2016 Mar 26;8(4):85. [PMC free article: PMC4848612] [PubMed: 27023607]

3.

Norris RL, Pfalzgraf RR, Laing G. Death following coral snake bite in the United States–first documented case (with ELISA confirmation of envenomation) in over 40 years. Toxicon. 2009 May;53(6):693-7. [PubMed: 19673084]

4.

Vergara I, Pedraza-Escalona M, Paniagua D, Restano-Cassulini R, Zamudio F, Batista CV, Possani LD, Alagón A. Eastern coral snake Micrurus fulvius venom toxicity in mice is mainly determined by neurotoxic phospholipases A2. J Proteomics. 2014 Jun 13;105:295-306. [PubMed: 24613619]

5.

Arce-Bejarano R, Lomonte B, Gutiérrez JM. Intravascular hemolysis induced by the venom of the Eastern coral snake, Micrurus fulvius, in a mouse model: identification of directly hemolytic phospholipases A2. Toxicon. 2014 Nov;90:26-35. [PubMed: 25088177]

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Disclosure: Matthew Hessel declares no relevant financial relationships with ineligible companies.

Disclosure: Scott McAninch declares no relevant financial relationships with ineligible companies.

Coral Snake’s Unique Poison: How It Works

Blue Coral Snake can kill not only frogs and rodents, but also other venomous snakes. For these purposes, evolution has provided him with a unique toxin that turns the last hours of the victim’s life into a living hell.

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We are accustomed to the fact that in the wild snakes usually feed on rodents and other small and harmless animals. However, the beautiful and deadly blue coral snake preys on fast and venomous snakes. Such a prey must not only be caught up, but also immobilized, and for this purpose the reptile uses a special poison that turns the last seconds of the prey’s life into real torture.

Do not self-medicate! In our articles, we collect the latest scientific data and the opinions of authoritative health experts. But remember: only a doctor can diagnose and prescribe treatment.

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Unique Snake Venom

A bright color in nature often symbolizes the creature’s danger, and just a glance at this snake immediately tells the enemy who he is dealing with. Found in southeastern Asia, blue coral snakes, or as scientists call them, two-banded ferruginous snakes (Calliophis bivirgatus), are distinguished by a bright red, neon-lit head and blue patterns throughout – it is not for nothing that they are included in the genus “Decorated Asps”. In an article published in the journal Toxins, researchers from the University of Queensland in Australia describe the unique properties of snake venom, which, when released into the bloodstream, provides the victim with an extensive shock to the entire physiological system.

What happens to the victim after being bitten

Almost immediately after being bitten, the victim goes into a catatonic state. The poison causes the entire nervous network of the body to chaotically strain the muscles, as a result of which the victim beats in spasmodic convulsions. Paralyzed and helpless, she eventually becomes the prey of a predator. Although this sounds very ominous, evolution had its own reasons for this: coral asps prey on other poisonous snakes, which have exceptional reaction, flexibility and an impressive arsenal of self-defense. A special venom is produced and stored in the gland, which makes up a full quarter of the snake’s total body.

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Why scientists are interested in the toxin

Scientists have already seen similar toxins in nature, but they have never been found in snakes, let alone other vertebrate species. Such poisons are characteristic primarily of scorpions and spiders. Conus, a predatory gastropod, injects a similar toxin into the fish, which instantly paralyzes them with spasmodically tensed muscles, similar to tetanus. The venom of the two-striped glandular snake has the same effect, and scientists say it is a good example of convergent evolution (the case when the same trait appears in several species of living creatures independently of each other). Researchers refer to its effect as spasmodic paralysis, while the venoms of other snakes cause peripheral paralysis. Interaction with poison blocks the ability of nerves to “turn off” sodium channels, which results in continuous signal transmission and, as a result, constant tension in muscle fibers.

Ironically, the dreaded toxin can be used for medical purposes. Currently, experts are developing drugs based on it that will act as an analgesic.

PALITOXIN AND CORAL POISONING | Mürgistusteabekeskus

Palitoxin is a toxin found in coral that can also be found in tropical fish, sea anemones and crabs in the Caribbean, Indian and Pacific Oceans and off the coast of Africa. However, the main sources of this toxin are corals of the family Palythoa and mostly soft corals ( Palythoa spp., Zoanthus spp. ) and dinoflagellates ( Ostreopsis spp. ).

The toxin can also be found in corals grown in home marine aquaria. Palitoxin is an activator of sodium-potassium channels in the body and is a potent vasoconstrictor.

The toxin is also absorbed through damaged skin and mucous membranes during coral handling. Poisoning can also occur when the toxin is inhaled if the corals have been cooked, crushed, or otherwise processed. It can also happen when cleaning the aquarium, especially during coral blooms. In no case should such corals be brushed. Coral poisoning can happen not only to people, but also to pets.

Symptoms of coral poisoning usually begin within 30-60 minutes of first contact, rarely within 2 hours. However, serious poisoning requiring immediate attention can occur even within 15 minutes of first exposure to the toxin. All people exposed to palytoxin should be monitored in a hospital, and full recovery may take longer.

The most common symptoms are cough, metallic taste in the mouth, dry mouth, gastrointestinal irritation, headache, dizziness and tingling in the hands. In more severe cases, palpitations, low blood pressure, slow heart rate, cyanosis, and muscle cramps are added.

There is no laboratory method for determining the content of palytoxin. The diagnosis of human poisoning is usually based on the information collected (the person knows they have eaten fish that may contain palytoxin, or cleaned a marine aquarium containing palytoxin-producing corals) but on a description of the health complaints that have occurred. There is no antidote for treatment, but treatment is supportive and symptomatic.

As a first aid for poisoning when cleaning the aquarium, leave the room as soon as possible and ventilate it thoroughly before returning. To date, there is no single well-proven method for cleaning surfaces, but a mildly acidic cleaner is often used.