When you are at the beach you never know what is lurking below. Find out what you can do if you encounter any of these dangers …
Jellyfishes are stinging creatures with stinging “cells,” which are highly specialised and designed to inoculate prey with venom. There may be millions of these stinging cells on the tentacles or near the mouth of the animal. When the cells are stimulated, they shoot out a stinging thread that releases microscopic granules of venom into the victim.
The victim may suffer immediate burning pain, skin rash, blistering, allergic reaction, or a number of systemic symptoms, including neurological syndromes, low blood pressure, abnormal heart rhythms, difficulty breathing, abdominal pain, nausea and vomiting, diarrhea, muscle cramping, and many others.
Treatment should be swift in order to minimize the clinical syndrome.
- Rinse the wound with seawater or concentrated salt solution if possible. A gentle fresh water rinse may cause more stinging cells to discharge their venom.
- There is growing support for hot water immersion therapy (113 degrees Fahrenheit or 45 degrees Centigrade), similar to that for a stingray or scorpionfish envenomation, for treatment of certain jellyfish stings.
- Anticipate an allergic reaction and be prepared to treat with injectable epinephrine and/or oral antihistamines.
- Do not rub the wound.
- Wear protective gloves (double thickness of a surgical glove or a thick dishwashing glove preferred).
- If the sting is from the box jellyfish Chironex fleckeri, flood the area with topical acetic acid 5% (vinegar) immediately and with a continuous application for a minimum of 30 minutes.
- Remove large tentacle fragments with forceps.
- DO NOT apply the pressure immobilization technique.
- Other topical decontaminants that may work, depending on the jellyfish species, include isopropyl (rubbing) alcohol, dilute ammonium hydroxide (household ammonia), powdered bicarbonate (baking soda), unseasoned meat tenderizer (papain), papaya fruit or juice, or lime or lemon (citrus) juice.
- After decontamination, remove adherent nematocysts by applying shaving cream or a paste of baking soda and shaving with a sharp edge, such as a safety razor.
- For a mild skin reaction, apply a topical corticosteroid (“steroid”) cream, ointment or lotion.
- If the reaction is moderate to severe, a physician may prescribe a systemic steroid or administer a steroid injection.
- Anti-tetanus immunization is standard.
- Observe closely for development of a wound infection.
- If the sting is from the box jellyfish Chironex fleckeri, there is an antivenom available in certain locales. The true efficacy of this therapy is currently under scrutiny.
Sea urchins are free-living echinoderms with egg-shaped, globular or flattened bodies. They are covered by tightly arranged spines and/or triple-jawed pedicellariae, which are seizing and envenoming organs. The spines can be brittle, hollow, sharp and venom-bearing or blunt and non venom-bearing. Most persons are envenomed when they step upon or brush against an urchin.
The clinical aspects are characterised by intense local tissue pain, which may radiate deeply into muscle. There may be redness and swelling, or perhaps punctuate purple discoloration. The latter may represent dye leached from the surface of a spine, rather than indicate a retained spine. If a spine resides near a joint, particularly in the hand, there may be inflammation, which can cause swelling of a finger or the entire hand. When multiple spines enter a victim, there may be nausea, vomiting, numbness and tingling, nerve dysfunction causing weakness or paralysis, fainting, low blood pressure, or difficulty breathing.
Therapy for a sea urchin puncture(s) is as follows:
- Extract any easily grasped spine fragments. Do not crush spines within the soft tissues.
- If any pedecellariae (seizing organs) are still attached, remove these with a sharp edge and something like shaving cream.
- For pain relief at any time during the process, immerse the wound(s) into non-scalding hot (113 degrees Fahrenheit or 45 degrees Centigrade) water to tolerance for 30 to 90 minutes. If pain recurs, repeat the hot water immersion.
- A doctor may need to use a local anesthetic for pain control.
- A doctor may need to obtain an x-ray, computed tomography (CT), magnetic resonance imaging (MRI) or ultrasound exam to locate the spine(s).
- If a spine is situated near or within a joint and is causing severe symptoms (e.g., inflammation, infection), it may need to be removed.
- A deep puncture wound of immune suppression of the victim is a possible indication of administration of a prophylactic antibiotic.
These treatment suggestions are similar to those that are recommended for puncture wounds from the spines of crown-of-thorns starfish.
Stingrays & Venemous Fish
Stingrays are a commonly incriminated group of envenoming animals. The spine is a serrated cartilaginous structure that houses venom glands covered by a fragile tissue sheath. Thus, when the spine enters a human victim, most commonly on the lower limb (ray is stepped upon) or upper limb (ray is handled), the tissue sheath is disrupted and venom enters the wound. Thus the injury is just a puncture/cut and an envenomation.
Marine venoms, similar to other toxins and poisons that originate in the animal and plant kingdoms, may cause a wide range of human physiological derangements. It is very important to remember that certain of these venoms, such as that elaborated by jellyfish, may invoke a serious allergic reaction.
The clinical aspects of a stingray envenomation are:
- Immediate intense pain
- Spine or fragments embedded in the wound
- Chest or abdomen may be punctured
- Dusky, swollen and bruised wound, with or without severe bleeding
- Muscle and fatty tissue may be affected in such a manner as to become severely inflamed or eventually destroyed
- Varying presence of systemic symptoms, including nausea, vomiting, diarrhea, sweating, dizziness, headache, seizures, unconsciousness, muscle twitching, paralysis, low blood pressure, abnormal heart rhythms
Stingrays may also bite humans with their grinding plate-type mechanism, with a force sufficient to sever a digit. This occurs when a person offers up a body part to a stingray, usually when handling or attempting to feed the animal.
The treatment for stingray envenomation is:
- Extract the spine or spine and tissue fragments, unless the spine is felt to possibly have penetrated a large blood vessel or other vital structure. In such a case, the spine should be managed as would be an impaled knife or other foreign object, and secured in place until advanced medical attention can be reached. This would be to allow the spine to be removed in a setting where rapid bleeding initiated upon its removal could be best managed.
- Immerse the wound into nonscalding hot (113 degrees Fahrenheit or 45 degrees Centigrade – “to tolerance”) water for 30 to 90 minutes or until there is significant pain relief. If this is successful in relieving pain, but pain recurs upon exit from the water, repeat the immersion. Do not immerse the affected part in ice water – this may actually cause a frostbite injury.
- Pain control may not be sufficiently obtained with hot water immersion, so the administration of pain medications, and/or the application of an anesthetic nerve block (local or regional) may be required.
- The wound should be explored and cleaned, then thoroughly rinsed.
- Imaging methods (such as x-ray, computed tomography [CT], magnetic resonance imaging [MRI}, etc.) should be deployed as needed to identify any suspected retained foreign bodies.
- Surgery may be necessary to remove spines or spine fragments.
- In the field, if possible, do not tightly close the wound. In other words, allow drainage of any possible fluid or pus collected without significant inhibition of such drainage.
- If the wound is significant (deep puncture or cut) or the victim has any reason to be immunosuppressed, consider administering antibiotics (a fluoroquinolone, tetracycline or doxycycline, or trimethoprim-sulfamethoxazole) as noted in my previous post about shark attacks.
Moving on to stonefish, scorpionfish and lionfish, these animals have 12 or 13 (of 18) dorsal venomous spines, as well as pelvic and anal venomous spines. As with the stingray, the spines are associated with venom glands. Some of these fishes can be very well camouflaged and difficult to locate against their native backgrounds, even for experienced divers. The clinical aspects vary a bit from stingray envenomations but the approach to treatment is precisely the same, with the notation that there is an antivenom available to treat stings of the Indo-Pacific species of stonefishes.
Other marine vertebrates that sting and cause injuries similar to scorpionfishes are weeverfishes, catfishes, dragonfishes, horned sharks, ratfishes, toadfishes, rabbitfishes, stargazers, squirrelfishes, sea robins, flying gurnards, and goosefishes.
These annoying but colurful floating pale blue coelenterates often sting bathers at Sydney beaches when summer afternoon onshore breezes cause them to drift inshore.
The stings are painful, and while it may hurt for several hours, no permanent scarring or fatalitities have been reported. More information page is available from the Australian Museum and the AVRU.
- Inactivation with vinegar prior to removal of the tentacle may or may not help, astonishingly no good studies have been done!
- Cooling with ice packs, hot water or towels (take care not to burn yourself), simple analgesics, EMLA or other local anaesthetic creams may help reduce pain.
- Do not rub the area with sand or a towel!
The Blue-Ringed Octopus
This small octopus (Hapalochaena maculosa) is found in tidal rock pools around Australia, and by 1983, 14 cases of envenomation were recorded in the literature, of which 2 were fatal and 4 life-threatening. Usually the bite is painless. Most bites are caused by people picking up or accidentally treading on the octopus; it does not seem to 'attack' human beings.
The octopus secretes a form of tetrodotoxin in its saliva. This has a selective blocking effect on nerve action potentials. One average sized octopus (weighing 26 grams) has enough venom to paralyse up to 10 adult human beings. No cardiotoxicity has been noted. Fixed dilated pupils may occur as a direct result of the toxin.
In the natural state the octopus either secretes the venom in the general vicinity of its prey, waits until it is immobile and then devours it, or else it jumps out and envelops the prey in its tentacles and either bites it or just secretes the venom all around it while it is held.
Envenomed patients notice paraesthesia, numbness, tightness in the chest, difficulty breathing and weakness; ultimately respiratory failure occurs, which may lead to death unless adequate resuscitation is instituted. The toxin has a short duration of action, however the onset of complete paralysis may be brief, ie under 10 minutes. If the airway is controlled, ventilation maintained and good intensive care management instituted before cerebral hypoxia occurs, then the outcome should be good. If there are no symptoms of systemic envenomation within 15 minutes of the bite, then usually nothing much happens.
If any signs of envenomation develop a firm crepe bandage should be applied, resuscitative equipment and medical assistance obtained if possible, and the patient should be transported with appropriate care to the nearest hospital. Expired air resuscitation should commence if respiratory failure develops, followed by early intubation and ventilation if facilities permit.
Sharks are found in oceans, tropical rivers and lakes. They range in size from 10 centimeters to over 15 meters (whale sharks). Approximately 30 out of 350 species have been implicated in human attacks. On average, there are fewer than 100 attacks reported each year worldwide, and less than 10% of these attacks are fatal. Sharks are superbly equipped predators, and can detect motion, chemicals, electrical signals, and vibration in the water, with a sensitivity that enables them to easily hone in on prey. The most dangerous sharks from a frequency-of-attack perspective are the white (“great white”, “white pointer”), tiger, bull, blue, dusky, hammerhead, and grey reef sharks. However, it is important to note that any shark, including the seemingly docile nurse shark, will bite a human if sufficiently provoked.
Some sharks can swim at speeds of up to 65 kilometres per hour underwater in bursts of motion. More than 70% of human victims are bitten only once or twice. Aggression seems to often be directed at a wounded or splashing (on the surface) victim.
The clinical aspects of shark bites include massive tissue loss, bleeding up to and including shock, and subsequent infection. Bites to the limbs are most common. The propensity for infection is great because of contamination with seawater, sand, plant debris, shark teeth, and the bacteria that reside within the mouths of sharks.
The general first aid principles are the same as those for other forms of trauma. These are to control the airway, support breathing, maintain the circulation, clean-trim-rinse wounds, apply appropriate dressings to the wounds, and administer antibiotics when indicated. In the field, depending on the degree of bleeding and remoteness from advanced medical care, bleeding control takes priority. Because the marine environment hosts a number of bacteria and other microorganisms that are not commonly a problem on land.
The danger appears to be greatest during summer months, in recreational areas, during late afternoon and evening, in murky and warm water, in deep water and drop-offs, and upon surface swimmers. All of these factors relate to the intersection of humans and sharks in the water and shark feeding and attack behaviour.
Shark attack prevention is obviously quite important. Here are some important risk mitigation recommendations:
- Avoid shark-infested water, particularly at dusk and at night.
- Do not swim with domestic animals in shark waters.
- Swim in groups; pay attention to your companions.
- Avoid turbid water, drop-offs, deep channels, and sanitation waste outlets.
- Do not bleed in the water.
- Avoid wearing shiny metal adornments that might mimic fishing lures. (This is particularly important to avoid barracuda bites.)
- Do not carry tethered (dead or injured) fish.
- Be alert for sharks when other fish in the vicinity act erratically.
- Do not tease or corner a shark. (This is important for any wild animal, and is particularly important to avoid moray eel bites.)
- Do not panic or splash at the surface of the water.
Sea snakes of the genus Astrotia are are found in Northern Australian waters and generally are not aggressive, except infrequently during the mating season. Astrokia Stokesii has been studied because it has fangs capable of penetrating a wetsuit.
The neurotoxic components of the venom are potent and appear to act on neuromuscular transmission, but only small amounts of venom are usually injected so fatalities are rare. More serious bites involve multiple serrated-edge lacerations. The venom is painless, like that of Australian terrestrial snakes, and this distinguishes sea snake bites from those of other marine creatures in this area.
Treatment and general information is the same as for terrestrial snakes. Firm crepe bandaging should be employed and not removed until the patient is in a suitable hospital. Specific sea snake antivenom is available and tiger snake antivenom may be used in an emergency.