Jellyfish stings

Cubozoa (Box Jellyfish)

These are almost invisible in water and represent the most significant hazard among jellyfish classes. They are often found in shallow coastal waters and harbors.

Chironex fleckeri (Australian box jellyfish/sea wasp), belonging to the order of multitentacled chirodropids, is only found in northern Australian waters. However, several other species of chirodropids found throughout non-Australian tropical realms are also capable of inflicting life-threatening envenomings. The toxin is dermonecrotic, cardiotoxic, and neurotoxic. Though the majority of victims suffer minimal symptoms, stings can cause immediate and excruciating pain. Skin manifestations include large welts and whiplike purple-red plaques. Severe envenomation is rare but can cause rapid cardiovascular collapse and death.

Carukia barnesi (Irukandji jellyfish), belonging to the order of smaller four-tentacled carybdeids, is notorious for the Irukandji syndrome. This is a poorly defined set of symptoms induced particularly by this species . The initial sting is often trivial. The symptoms of Irukandji syndrome develop after 20–30 minutes with victims showing three patterns of symptoms: pain, catecholamine-like effects, and cardiopulmonary decompensation. Symptoms range from headaches, through severe pain, nausea, vomiting, and cardiopulmonary distress, sometimes resulting in death. Although the syndrome was originally documented in coastal northern Australia, it has subsequently been reported in other areas.

Hydrozoa

Physalia physalis (Portuguese man-of-war) and the smaller Physalia utriculus (bluebottle) mostly inhabit ocean waters and are particularly notable for their floating bladder-like pneumatophore, long tentacles, and the immediate, intense cutaneous pain of their sting resulting in possible necrosis and systemic reactions, with potentially fatal outcomes.

Scyphozoa (True Jellyfish)

The majority of jellyfish envenomings throughout the world occur from the scyphozoans.

Pelagia noctiluca (mauve stinger), found worldwide but most commonly in warmer waters like the Mediterranean, is capable of inflicting an excruciatingly painful, severe inflammatory reaction with possible cutaneous necrosis, but systemic reactions are rare.

Chrysaora quinquecirrha (sea nettle), mostly found in ocean waters, causes a mild-to-moderately painful sting.

Cyanea capillata (lion’s mane) prefers cooler northern oceans and seas and can claim to achieve the biggest size within the Medusozoa subphylum, reaching a weight of up to a metric ton. Its sting produces minor to severely painful local reactions with occasional self-limiting systemic reactions.

Anthozoa (Corals and Sea Anemones)

Sea anemone stings range from mild erythema and tingling to painful urticarial and vesiculobullous lesions. Stings from corals are usually mild. ‘Coral cuts’ from the hard coral exoskeleton are more serious and may introduce debris, bacteria, and other infections into the wound.

Seabather ’ s Eruption (Sea Lice)

This is an acute dermatitis caused by larvae of thimble jellyfish (Linuche unguiculata) and sea anemone (Edwardsiella lineata) . It has been reported along the west Atlantic coast and in southeast Asia. The rash, usually confined to underneath the bathing suit, is a highly pruritic erythematous papular eruption. Symptoms usually begin within hours to 15 days after exposure.