Key Insights On Treating Marine-Related Injuries To The Lower Extremity

Trout season has just begun in Pennsylvania and it made me wax poetic for the Goldfarb Foundation’s Montana conference, which combines fly fishing and continuing education lectures. During this past year’s conference in Missoula, Mt., I caught a lovely 20-inch brown trout and I got hooked on a new sport (pun intended).

Since the season to fish in the freshwater streams has begun and some of you might travel to the coasts to escape from the winter we have had, it would be a good time to review some marine injuries. Patients with the acute form of these injuries will present to the emergency department. However, it is important that physicians recognize the sequelae of exposure to freshwater and saltwater animals in addition to exposure to home tanks.

Accordingly, let us discuss a few creatures that would come in contact with the lower extremity fairly easily, starting with jellyfish. Stings from Scyphozoa, also known as true jellyfish, produce pain, itching and burning upon contact, but may manifest as linear wheals and vesicles a few hours later.1 Generalized itching and allergic reaction may occur. Systemic reactions may occur in children and may rarely occur in adults due to the amount of contact and size of the patient, but these reactions are self-limited and will resolve in a few weeks.

Rinsing vinegar over the affected area to destroy the nematocysts on the skin is the first line to stop further envenomation of the nematocysts that are attached to the skin. If vinegar is not available, one can use sea water to rinse the area as well. However, do not use fresh water as it can cause the nematocysts to release venom. When I think of jellyfish stings, I remember the Friends episode where Chandler uses urine to take the sting away from Monica’s injury. However, there is no scientific data to support the use of urine, vodka or soda to inactivate the nematocysts and use of these liquids can potentially make the sting worse.

The brown and purple plaques left by C. fleckeri, or the box jellyfish, are not to be taken lightly. Found in the waters of northern Australia, the box jellyfish is the most toxic jellyfish in the world and can cause cardiac and pulmonary failure.2 An anti-venom exists for this species and may even be coupled with antibiotics in the presence of skin necrosis.

Also found near Australia, the Portuguese man o’ war is not a true jellyfish and one should not use vinegar to wash away the nematocysts. Apply salt water to the area. Use caution when removing the animal whether it is alive in the water or washed up dead on the beach.

If you are in the southern part of the United States, you may have encountered a catfish in a muddy river or lake.1 Catfish won’t purposely attack you. However, by stepping on one of their three spines, which have venomous glands beside them, a significant puncture wound can ensue. Fragments of the spine left in the foot can cause severe pain, edema, erythema, nausea and, in severe cases, seizure, paralysis and death.

First aid consists of soaking the foot in hot water and systemic analgesia. The venom will degenerate in heat but severe pain can occur when removing the foot from the hot water. Following the hot water soak, removal of the spine (if still present) and local wound care is advised with antibiotic prophylaxis as needed.

Jaws, jellyfish and catfish. All of those creatures make me just want to jump into the water — as long as I am wearing waders, nice, protective boots and an armored suit.

References

1. Haddad V Jr, Lupi O, Lonza JP, Tyring SK. Tropical dermatology: marine and aquatic dermatology. JAAD. 2009; 61(5):733-50.
2. Daubert GP. Cnidaria envenomation. https://emedicine.medscape.com/article/769538-overview