Jellyfish sting: symptoms, consequences, how to treat

A pleasant seaside holiday, swimming can be spoiled by a jellyfish bite. These sea creatures look beautiful in the water due to their bell-shaped form, thrusting movement with the help of muscle contraction, transparent walls capable of colored glow. But near their mouth opening there are blades equipped with special stinging cells - cnidocytes, which contain a substance for their own protection and hunting for prey. When in contact with a jellyfish, it gets on the body and burns it.

Epidemiology

It is estimated that there are 150 million jellyfish stings per year [ 1 ], with up to 800 daily events recorded in some areas of the Pacific Ocean [ 2 ]. So, in addition to being a public health issue, jellyfish also pose a threat to tourism.

Pathogenesis

Skin contact with nematocysts resembles a prick, and the subsequent inflammation and nerve irritation cause pain, swelling and itching, which may lead to skin necrosis in more severe bites (common in Australian chiropedid cubozoans) [ 3 ]. The local effect of the venom is due to thread penetration and the activity of various compounds such as phospholipase A2 [ 4 ], as well as exocytosis of mast cell granules (and thus possibly histamine release) [ 5 ]. Nematocysts can also cause potential systemic symptoms - due to the release of toxins into the general bloodstream [ 6 ] - including gastrointestinal (mainly Physalia physalis and Pelagiidae spp.), muscular ( Physalia and cubozoans spp.), cardiac ( Physalia and cubozoans spp.), neurological ( Physalia and cubozoans spp.) and allergic manifestations (Pelagiidae and cubozoans spp.). Jellyfish toxins have also been reported to include hemolytic and lethal fractions [ 7 ]. Lethal fractions may contain cardiotoxins, which can cause ventricular arrhythmias and cardiac arrest, and neurotoxins, which can cause respiratory failure and respiratory arrest [ 8 ]. Intravascular hemolytic fractions can also cause acute renal failure. Cnidarians venom is also immunogenic, capable of inducing an antibody response.

Symptoms jellyfish sting

The reaction to a jellyfish sting varies depending on the species and size. The cnidocytes of some are sharp-pointed threads that stick into the body like a harpoon and release their poison, while others are long or short, clinging to or entangling the victim.

Jellyfish venoms consist of powerful protein porins (cell membrane pore-forming toxins), neurotoxic peptides, bioactive lipids, and other molecules.[ 9 ] Upon contact with human skin or other surfaces (such as the cornea), thousands of toxin-containing tubules are deposited in the epidermis and dermis, causing local and systemic damage and may also induce immunological reactions.[ 10 ]

What does a jellyfish sting look like? The most common symptom of a jellyfish sting is a burn that resembles an allergy. It manifests itself:

• redness at the site of contact;
• the appearance of a rash;
• pain;
• itching, the desire to constantly scratch the affected area;
• When in contact with a large specimen, small blisters in the rash may merge into blisters;
• elevated body temperature;
• vomiting, nausea after extensive contact;
• sometimes anaphylactic shock.

It is a very unpleasant sensation if a jellyfish stings your eyes. This causes a burning sensation, redness, and tearing.

A distinct syndrome has been described for stings from small four-bristled box jellyfish, called Irukandji syndrome, characterized by sweating, restlessness, muscle spasm, severe hypertension, potentially late hypotension, and cardiac failure.[ 11 ]

Types of Jellyfish

Since the boundaries of the modern world have expanded significantly, it is necessary to have an idea not only about the jellyfish that live in our inland seas, but also far beyond them. It is necessary to know what the bites of the inhabitants of those waters look like, where you will travel, and what they are fraught with.

• The bite of the cross jellyfish (Gonionemus vertens) - these sea creatures can be found in the Pacific Ocean, a small population is also in the Atlantic, its western part. They got their name because of the orange cross on the top of the transparent dome - the sex glands, along the perimeter of which are located tentacles with poison (about 60). Their maximum diameter reaches 40 cm.

The greatest number of jellyfish usually appear in late summer and early autumn when the weather is warm. Their poison is designed for small sea creatures (shrimp, fry) and cannot kill a person, but it has a neuroparalytic property and is perceived as an electric shock. It can cause attacks of suffocation and even convulsions, which for those in the water can result in drowning. The bite of G. vertens causes a burning sensation in the skin, which is accompanied by the rapid appearance of blisters and local swelling, after 10-30 minutes - general weakness. Numbness occurs, as well as pain in the joints of the arms and legs; breathing becomes difficult and can temporarily stop. Sometimes there is a violation of liver function. Acute symptoms last from four to five days. [ 12 ]

• Black Sea jellyfish sting - there are two species of relatively large jellyfish in the Black Sea: Aurelia and Rhizostoma pulmo. The first is relatively harmless and can leave weak marks in the form of slight redness. [ 13 ] Lesions can heal for more than ten days. [ 14 ] The second reaches half a meter in size and is more poisonous. After it, blisters and a rise in temperature can appear, and in some cases, the functions of internal organs can be disrupted. In Rhizostoma or blue jellyfish (due to its coloring), stinging cells are located only in the oral lobes, which are numerous processes, and are not on the dome, so its touch is not dangerous. The umbrella is hemispherical, bell-shaped, without tentacles; several marginal lobes are present.

Rhizostoma pulmo is moderately toxic. However, contact with Rhizostoma pulmo may cause erythematous and ulcerative lesions; rare cases of dermatitis are described as mild erythema, resolving spontaneously within a few hours, although burns on the skin and especially the lips, sneezing and rhinorrhea, urticaria and systemic symptoms have been reported [ 15 ]. Cases of contact dermatitis have been recently reported, confirming its toxicity to humans: contact caused immediate cutaneous pain followed by an erythematous, slightly infiltrated eruption and vesicle formation; after topical corticosteroid therapy, the pain disappeared within 36 hours.

Complications and consequences

How long does it take for a jellyfish sting to heal? Everything is individual and depends on the size of the sea animal and the composition of its venom. Thus, the venom of the cross spider is excreted from the body in 4 days, and for some more dangerous species, 2-3 weeks. Scars may even remain on the body.

Is there a real health risk associated with a jellyfish sting? A type of jellyfish known as the sea wasp, which lives in the waters of Thailand, where travelers often go to escape the winter, not only leaves scars, but also poses a mortal threat to life, since in some cases it leads to cardiac arrest. To prevent this from happening, an antidote must be administered immediately.

Are jellyfish stings beneficial? Scientists claim that their venom brings relief to those suffering from rheumatism, relaxing muscles stiffened by the disease.

A jellyfish sting during pregnancy (many expectant mothers like to spend their last free days by the sea) has the same consequences as for other people.

Treatment jellyfish sting

Treatment of jellyfish stings is aimed at: relieving the local effects of the venom, preventing further nematocyst shedding, and controlling systemic reactions, including shock. In severe cases, the most important step is stabilization and maintenance of vital functions.

Oral or topical analgesics, 30-second application of household vinegar (4–6% acetic acid) to prevent further dissemination of nematocysts remaining on the skin may be used.[ 16 ] Conversely, alcohol, methylated spirits, and fresh water should be avoided as they may promote release of nematocysts; pressure immobilization dressings should also be avoided as studies show that they stimulate additional release of venom from nematocysts.

Most often, a jellyfish sting does not require special medical care, unless it is a large area of damage, a strong allergic reaction with tachycardia, and difficulty breathing.

What to do if you get stung by a jellyfish?

The most suitable method for removing the tentacles is still debated, as these procedures may stimulate further release of nematocysts [ 17 ]. It is necessary to immediately get to dry land and, without touching the damaged area, pour salt water on it [ 18 ], [ 19 ], and also use tweezers to remove the tentacles [ 20 ]. Using, for example, a plastic card, a razor or a knife, remove the stings. To do this, the objects should be held at an angle of 30º to the body. The tentacles can also be removed with bare hands, but it is better to immediately thoroughly wash the rescuer's fingers to prevent secondary stings. After removing all the tentacles, the wound is washed with warm water, ice can also be applied, as it slows down the diffusion of the venom, thus acting as a painkiller, while the mechanism of pain relief from warm objects is still debated. Some authors argue that heat can modulate pain receptors, resulting in a reduction in pain sensation.

High doses of intravenous ascorbate have been reported to reduce pain within 10 minutes of administration. Vitamin C is considered effective against various toxins.[ 21 ]

Immobilizing dressings over jellyfish stings remains controversial and is considered potentially dangerous [ 22 ], with some not recommending them as a first aid measure. Significant amounts of venom may remain in the unreleased nematocysts that adhere to the patient's skin, and pressure from the dressing may encourage the venom to be squeezed out of them. [ 23 ]

How to treat a jellyfish sting? Antihistamine ointments and aerosols, oral agents will help relieve itching and irritation, after which you can apply a gauze bandage. It is recommended to drink a lot at this time.

Jellyfish Sting Remedies

For jellyfish burns, you can use ointments and creams based on corticosteroids: Akriderm, Triderm, Belogent, Celestoderm, etc.

From tablets you can use the following antihistamines: citrine, edem, diazolin, suprastin. [ 24 ]

Research into topical inhibitors as effective measures to prevent jellyfish stings is ongoing and shows promise [ 25 ]. Skin inhibitor cream (Safe Sea®, Nidaria Technology, Zemah, Israel) is already available in many countries around the world and provides protection to swimmers from jellyfish stings. This product has recently been developed as a waterproof sunscreen containing octyl methoxycinnamate and zinc oxide, which inactivates jellyfish and protects against sunburn. Its water-repellent properties make it more difficult for jellyfish to attach their tentacles to the body, and the chemicals it contains block the release of venom from the stinging cells. However, it does not help after a jellyfish sting.

Can you swim after a jellyfish sting?

Depending on how you feel and the condition of your skin, you can decide whether to swim or not. Sea water will not harm a minor lesion, so there is no need to waste a day without water procedures.

Prevention

The best thing to do is to take care of how to avoid a jellyfish sting. First, do not go to the sea during the season of their accumulation. From the point of view of preventive medicine, divers and swimmers in dangerous areas should wear personal protective equipment. They are, in fact, almost completely effective against all jellyfish stings and are generally recommended for all people (tourists, locals and diving enthusiasts). [ 26 ] Also, in the water and on land, avoid contact with them. In places equipped for swimming, the influx of jellyfish is monitored, and a purple flag is hung out, notifying of the danger in the water. The use of a lotion designed to protect against their stings will prevent dangerous consequences.