With the jellyfish population along Delaware’s beaches higher than normal this summer, even if the floating balloon like creatures are not clearly seen, bathers may suffer from itching and burning skin when they leave the water. Known by the medical profession as “sea bather’s eruption,” the cause is often due to a microscopic organism commonly called “sea lice.”
“The term sea lice is not exactly accurate as these are not bugs like traditional lice,” Susan Capon, a primary care physician, said. “Instead, these are actually jellyfish, sand flea or sea anemone larvae that latch onto skin and clothing. They do not feed off blood like traditional lice but release a stinging toxin into the body similar to jellyfish or anemone adults.”
Sometimes, the small, microscopic creatures just cause some minor discomfort a few minutes after a bather leaves the water, but they can also case a skin rash that can appear up to 24 hours later. Often, the rash appears minutes after stepping from the water.
“The rash commonly appears in areas covered by bathing suits or in areas where there is significant body hair,” Capon said. “The rash is extremely itchy, and you may see raised, red blisters or welts. The rash can be more severe in children who may also experience abdominal pain, diarrhea, fever, nausea and vomiting, although those symptoms are not common.”
The larvae that cause sea bather’s eruption live in saltwater, not freshwater and outbreaks can be unpredictable. Getting the rash at a local beach this year does not mean you will get the same rash next year. An early sign that there may be larvae present is a tingling under a swimsuit.
Treatments for sea bather’s eruption include rinsing the area with diluted vinegar or unaffected saltwater to neutralize the toxins. Do not rinse with freshwater as that can cause the larvae to sting more. Shower with freshwater after treating the area. Do not jump in a pool or rub with a towel as these will cause the trapped larvae to sting again.
Do not allow swimwear to dry and then put them back on without washing thoroughly in hot water. Like jellyfish, the nematocysts that hold venom can be triggered by rehydration even though the larvae themselves have died. Capon recommends putting the suit in a sink filled with hot water and detergent before tossing it in the washing machine. Dry the suit in a dryer to be sure the nematocysts are destroyed.
“Calamine lotion can be used to help with the itching,” Capon said. “If you develop a severe rash, have difficulty breathing, have a high fever or the rash becomes infected, seek medical attention immediately. You should also seek medical attention if red streaks extend from the rash.”
