AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

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

INTRODUCTION

Section 2 of 10  

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

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, Haplochlaena lunulate and the southern blue-ringed octopus (also known as the Australian spotted octopus) Haplochlaena maculosa, which are found in coastal waters and tide pools around Australia. A third species, the blue-lined octopus Haplochlaena 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

Section 3 of 10  

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

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.

DIFFERENTIALS

Section 4 of 10  

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

WORKUP

Section 5 of 10  

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

Lab Studies

• Laboratory studies are non-contributory.
• 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

Section 6 of 10  

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

Prehospital Care

• Cardiopulmonary support, including endotracheal intubation and cardiopulmonary resuscitation (CPR), as clinically indicated.
• What constitutes proper wound care 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 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

Section 7 of 10  

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

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 this type envenomation is not yet established.

FOLLOW-UP

Section 8 of 10  

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

Further Inpatient Care

• The patient 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 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

Section 9 of 10  

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

Medical/Legal 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.

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• 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].

Article Last Updated: Jan 4, 2007