eMedicine Specialties > Emergency Medicine > Environmental

Octopus Envenomation

Jon Mark Hirshon, MD, MPH, Associate Professor, Department of Emergency Medicine, University of Maryland School of Medicine

Updated: Aug 14, 2008

Introduction

Background

Octopuses, which are organisms of the class Cephalopoda in the phylum Mollusca, are generally harmless and unlikely to be aggressive unless provoked.

Their bites are rarely life threatening, except for the bite of the greater blue-ringed octopus, Hapalochlaena lunulata and the southern blue-ringed octopus (also known as the Australian spotted octopus) Hapalochlaena maculosa, which are found in coastal waters and tide pools around Australia. A third species, the blue-lined octopus Hapalochlaena fasciata, has also been described. These octopuses grow up to 20 cm in length with tentacles extended. They are normally light-colored with dark brown bands and blue rings or patches. When disturbed, their bodies darken, and the blue circles turn iridescent blue. Their venom can be released into the water to paralyze their prey, but its effects on humans primarily occur by injection of the venom upon biting.

Pathophysiology

There are many fractions in the venom secreted from the salivary glands of the blue-ringed octopus, one of which is identical to tetrodotoxin. This substance blocks voltage-gated fast sodium channel conduction, blocking peripheral nerve conduction, which can lead to paralysis and death from respiratory failure. Nerve conduction studies in tetrodotoxin-poisoned (puffer fish) persons have demonstrated reduced motor and sensory conduction velocities consistent with inhibition of sodium currents at the node of Ranvier. Reported central nervous system effects of tetrodotoxin in humans have included nausea and emesis, miosis, diabetes insipidus, and depressed cortical activity.

Other fractions of the venom include 5-hydroxytryptamine, hyaluronidase, tyramine, histamine, tryptamine, octopamine, taurine, acetylcholine, and dopamine.

Frequency

United States

The blue-ringed octopus does not naturally dwell in the coastal waters of the US.

International

Rare cases of octopus envenomation occur in the Indo-Pacific region.

Mortality/Morbidity

Mortality is rare. Full recovery is expected when appropriate measures are undertaken.

Age

Individuals bitten by a blue-ringed octopus would have to be old enough and mobile enough to be able to walk or swim in the tide pools and coastal waters of Australia.

Clinical

History

Any octopus can bite with its parrot-like chitinous beak.

The bite of the blue-ringed octopus is usually painless; however, the individual may experience a reaction similar to a bee sting.
If envenomation has occurred, symptoms are likely to start within 10 minutes of being bitten.
If a significant envenomation has occurred, the individual will rapidly progress from perioral and peripheral paresthesias through the following signs and symptoms.
- Nausea and vomiting
- Blurred vision
- Ataxia
- Muscle paralysis
- Respiratory failure, which may lead to cardiac arrest and death
Anaphylactoid or anaphylactic reactions have rarely been reported.

Physical

The individual is usually bitten on an extremity and sustains 1-2 small puncture wounds.
Local reaction may be minimal, but it can progress to include pain, edema, and erythema of the entire extremity.
The patient becomes flaccid once paralyzed.

Causes

Envenomations usually occur when an individual picks up a blue-ringed octopus or accidentally steps on one.

Differential Diagnoses

Lionfish and Stonefish
Snake Envenomations, Sea
Stingray Envenomations
Toxicity, Tetrodotoxin

Workup

Laboratory Studies

Laboratory studies for octopus envenomation are noncontributory.
A general workup for a critically ill patient is recommended to rule out other etiologies for acute paralysis and respiratory failure.

Imaging Studies

Imaging studies are generally not helpful.
A plain film of the puncture site may be indicated to rule out a foreign body.

Treatment

Prehospital Care

Cardiopulmonary support, including endotracheal intubation and cardiopulmonary resuscitation (CPR), as clinically indicated.
What constitutes proper wound care for octopus envenomation is controversial. Options include the following:
- Immediately irrigate and care for the wound, as one would for any puncture wound.
- Perform local suction without incision or local sequestration of the venom by applying a constricting band proximal to the injury.
- Perform pressure immobilization technique, which is done by compressing a cloth pad with a bandage directly over the wound and surrounding tissues at 9.3 kPa (70 mm Hg) or greater of pressure.

Emergency Department Care

Treatment of octopus envenomation is supportive.

Provide endotracheal intubation and ventilatory support until the venom has worn off, usually within 4-10 hours.
Confirm that the patient's tetanus status is current.
No antivenin is available.
Neostigmine and edrophonium have shown benefit in restoring muscular strength in some cases of tetrodotoxin intoxication (eg, puffer fish), but have not undergone clinical trials in blue-ringed octopus envenomations.
4-Aminopyridine (Neurelan - US, Pymadine), a drug utilized as an antagonist to nondepolarizing neuromuscular blocking agents (available in the US as an orphan drug for multiple sclerosis), has been shown to reverse tetrodotoxin toxicity in animal experiments.

Consultations

A general surgery consult may be indicated for wide excision of the wound. However, this has not proven to improve outcome.
A medical toxicologist (certified by the American Board of Medical Toxicology or the American Board of Emergency Medicine), or a poison control center certified by the American Association of Poison Control Centers, should be contacted regarding this uncommon intoxication.

Medication

The goal of pharmacotherapy is to reduce morbidity and prevent complications. Administration of nondepolarizing neuromuscular blocking antagonists may be beneficial. 4-Aminopyridine (Neurelan) is utilized as an antagonist to nondepolarizing neuromuscular blocking agents (available in the US as an orphan drug for multiple sclerosis), has been shown to reverse tetrodotoxin toxicity in animal experiments. The dosing regimen for use in octopus envenomation is not yet established.

Follow-up

Further Inpatient Care

The patient with octopus envenomation should be admitted to an intensive care unit until the venom has worn off, usually in 4-10 hours.
If significant hypoxia has not occurred, recovery is usually rapid.

Further Outpatient Care

Local wound care follow up is prudent.

Complications

If acute paralysis and respiratory arrest is not immediately recognized and appropriately treated, anoxic brain injury or death will result.

Prognosis

The prognosis for octopus envenomation is generally excellent, unless significant hypoxia has occurred.
Patients should be warned that anaphylactic reactions may result in ongoing symptoms (eg, joint pains, effusions) for up to several weeks.

Patient Education

Individuals in Australian coastal waters must be educated to take care where they step in tide pools and not to pick up an octopus.
For excellent patient education resources, visit eMedicine's Bites and Stings Center. Also, see eMedicine's patient education article
Stingray Injury.

Miscellaneous

Medicolegal Pitfalls

The main pitfall is failure to recognize the patient's inability to maintain a patent airway and adequate respirations, leading to a failure to provide airway support and supportive treatment until the toxin has worn off.

Multimedia

Media file 1: Blue-ringed octopus. Image courtesy of Simon Dubbin.

References

Auerbach PS. Marine envenomations. N Engl J Med. Aug 15 1991;325(7):486-93. [Medline].
Chang FCT, Spriggs DL, Benton BJ, et al. 4-Aminopyridine reverses saxitoxin (STX)- and tetrodotoxin (TTX)- induced cardiorespiratory depression in chronically instrumented guinea pigs. Fundam Appl Toxicol. Jul 1997;38(1):75-88. [Medline].
Flachsenberger WA. Respiratory failure and lethal hypotension due to blue-ringed octopus and tetrodotoxin envenomation observed and counteracted in animal models. J Toxicol Clin Toxicol. 1986-87;24(6):485-502. [Medline].
Kizer KW. Marine envenomations. J Toxicol Clin Toxicol. 1983-84;21(4-5):527-55. [Medline].
McGoldrick J, Marx JA. Marine envenomations. Part 2: Invertebrates. J Emerg Med. Jan-Feb 1992;10(1):71-7. [Medline].
Nimorakiotakis B, Winkel KD. Marine envenomations. Part 2--Other marine envenomations. Aust Fam Physician. Dec 2003;32(12):975-9. [Medline].
Oda K, Araki K, Totoki T, et al. Nerve conduction study of human tetrodotoxication. Neurology. May 1989;39(5):743-5. [Medline].
Walker DG. Survival after severe envenomation by the blue-ringed octopus (Hapalochlaena maculosa). Med J Aust. Dec 10-24 1983;2(12):663-5. [Medline].
Watters MR, Stommel EW. Marine Neurotoxins: Envenomations and Contact Toxins. Curr Treat Options Neurol. Mar 2004;6(2):115-123. [Medline].

Keywords

octopus envenomation, octopus poisoning, octopus bite, blue-ringed octopus envenomation, Hapalochlaena lunulata envenomation, Hapalochlaena maculosa envenomation, Cephalopoda, Mollusca

Contributor Information and Disclosures

Author

Jon Mark Hirshon, MD, MPH, Associate Professor, Department of Emergency Medicine, University of Maryland School of Medicine
Jon Mark Hirshon, MD, MPH is a member of the following medical societies: Alpha Omega Alpha, American Academy of Emergency Medicine, American College of Emergency Physicians, American Public Health Association, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Medical Editor

Dana A Stearns, MD, Assistant Director of Undergraduate Education, Department of Emergency Medicine, Massachusetts General Hospital
Dana A Stearns, MD is a member of the following medical societies: American Academy of Emergency Medicine and American College of Emergency Physicians
Disclosure: Nothing to disclose.

Pharmacy Editor

John T VanDeVoort, PharmD, ABAT, Director of Pharmacy, Sacred Heart Hospital
John T VanDeVoort, PharmD, ABAT is a member of the following medical societies: American Academy of Clinical Toxicology and American Society of Health-System Pharmacists
Disclosure: Nothing to disclose.

Managing Editor

James Steven Walker, DO, MS, Clinical Professor of Surgery, Department of Surgery, University of Oklahoma Health Sciences Center
James Steven Walker, DO, MS is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, American College of Osteopathic Emergency Physicians, and American Osteopathic Association
Disclosure: Nothing to disclose.

CME Editor

John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center
John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Chief Editor

Scott H Plantz, MD, FAAEM, Associate Clinical Professor of Emergency Medicine, Rosalind Franklin University of Medicine and Science, Chicago Medical School; Medical Director, WeCare Med,Inc
Scott H Plantz, MD, FAAEM is a member of the following medical societies: American Academy of Emergency Medicine
Disclosure: Nothing to disclose.

Further Reading