Research to improve the quality of antivenom and the treatment system using antivenom (AMED Ato Group)

Other Marine Envenomation

Portuguese Man-of-War(Scientific name: Physalia physalis utriculus)

Portuguese Man-of-War(Scientific name: Physalia physalis utriculus)

Appearance

A lovely blue hue.Also called “blue bottles,” they have a bluish-white floating hood from which tentacles extend to reach a length of 10–20 m. The Portuguese man-of-war is also called the “electric jellyfish” because its tentacles contain many nematocysts that induce a strong sensation akin to an electric shock.

Epidemiology

An outbreak of Portuguese man-of-war envenomation in southeastern Brazil was reported in 2013. In addition, a massive outbreak at Yuigahama Beach, Japan, occurred in 2018.

Venom activity and clinical symptoms

Portuguesemanof-war venom induces hemolysis, swelling, and necrosis and can be lethal. Extreme pain is experienced immediately following the sting. Areas of skin that contact the man-of-war’s tentacles form swollen welts that appear as a linear papular rash.

Diagnosis

Currently, there are no definitive diagnostic criteria for Portuguese man-of-war envenomation. The diagnosis is based on the patient’s history or positive identification of the Portuguese man-of-war presented by the patient.

Treatment

Use sea or tap water to wash away any tentacles that remain wrapped around the body. If tentacles cannot be rinsed off, gently remove them with the fingertips. Do not use vinegar as you would for box jellyfish stings because this promotes nematocyst firing in the Portuguese man-of-war. Use strong topical steroids if inflammation at the site of the sting is severe.

Prevention

Do not enter the ocean when alerted to the presence of jellyfish. Swim in areas protected by an antijellyfish barrier net. Minimize exposure of unprotected skin as much as possible.

Geography Cone(Scientific name: Gastridium geographus)

Geography Cone(Scientific name: Gastridium geographus)

Appearance

The shell of the geography cone grows to a size of 10–13 cm and it beautifully intertwines clouds of crimson with a fine mesh pattern.

Epidemiology

Araki et al. reported 18 cases from Okinawa prior to 1991; 13 were from G. geographus envenomation, of which 4 were fatal.Kohn reported 43 cases of victim, of which 15 (35%) were fatal.

Venom activity and clinical symptoms

G. geographus is the most dangerous species known to humans. Conotoxins target receptors and channels that mediate neuromuscular blockade. Paralysis at the site of injury, dizziness, double vision, numbness of the mouth, and other symptoms may occur. In severe cases, ventilatory support may be required.

Diagnosis

Currently, there are no definitive diagnostic criteria for geography cone envenomation. The diagnosis is based on the patient’s history or the positive identification of the geography cone presented by the patient.

Treatment

The wound should be soaked in hot water (maximum 45 °C) for 30–90 min. Standard medical care should be provided. Mechanical ventilation may be required in severe cases. There is no antivenom for a geography cone sting. Treatment is supportive until the toxins become inactive.

Prevention

Do not pick up seashells carelessly.

Blue-Ringed Octopus (Scientific name: Hapalochlaena fasciata)

Blue-Ringed Octopus (Scientific name: Hapalochlaena fasciata)

Appearance

A small octopus approximately 10 cm in length. The skin is yellow and spotted with blue circles.

Epidemiology

H. fasciata is most commonly found around intertidal rocky shores and coastal waters between Australia and through the Pacific Ocean north to Japan.

Venom activity and clinical symptoms

Blue-ringed octopus venom includes tetrodotoxin and can cause respiratory muscle paralysis.

Treatment

Standard medical care should be provided. Mechanical ventilation may be required in severe cases.

Prevention

The blue-ringed octopus may be found during clam digging when large rocks are overturned. They should not be touched with bare hands.

References
Hifumi T, et al. SN Comprehensive Clinical Medicine (2020) 2:2288–2292