Visiting Myrtle Beach? Just watch out for sea lice in the ocean. A swimmer’s guide

Visitors to the Grand Strand beaches have long been enthralled by their marine biodiversity, promising once-in-a-lifetime opportunities to spot flying squirrels, loggerhead turtles and even sharks cutting across the Atlantic.

Less likely to be on that oceanic bucket list are sea lice, although social media searches for the term in several Grand Strand-area Facebook groups show it remains an ever-popular topic.

Be warned: These crustaceans are not only bountiful, but can leave a most uncomfortable souvenir for its hosts.

Here’s what you need to know about these critters, also dubbed “seabather’s eruption.”

They aren’t actually insects

Sea lice are copepods — a microscopic type of crustacean related to crabs, shrimp and lobsters. With nearly 15,000 identified species, the creatures are found anywhere there’s water and are a vital part of the food chain for many types of birds, fish and whales.

Now that the science is out of the way, what exactly are sea lice?

They’re a small type of jellyfish still in their immature form and can easily get trapped in hair or bathing suits.

”When you get out, the water drains off of you, but the larvae stay behind. Your bathing suit rubs against your skin, causing the larvae to sting you and inject their toxin,” is how WebMD.com explains the sea lice plan of attack.

Salmon are also plagued by a type of sea louse, but it’s an unrelated type of parasite.

Impossible to ignore, but not life threatening

A tingling sensation in areas where the larvae got trapped — most commonly under clothing and in hair — could be the first signal of a sting. Itching could start a short time later, according to Riverchase Dermatology, which has offices along the Florida coast.

The rash usually appears between four and 24 hours after swimming. A small number of people may develop additional symptoms including chills, fatigue and nausea.

How can I avoid being stung?

Jellyfish larvae are most abundant between April and July, so chances of an outbreak increase during those months. Pay attention to weather reports, too, since wind currents and tidal changes can bring the larvae closer to shore in greater numbers.

Don’t wear a T-shirt or other top while in the ocean, as it gives sea lice more surface area to latch onto.

Wearing tight bathing suits or putting one on that hasn’t been washed or dried can also up the chances of a sea lice assault, since the stinging cells aren’t alive and can cling to clothing.

Treating a sea lice sting can be done at home in several ways

Riverchase Dermatology has several suggestions on its website for people who have been stung

• Wrap ice packs in a towel or cloth and place them on the stung areas

• Take a non-steroidal, anti-inflammatory drug such as ibuprofen to help relieve pain and inflammation

• Apply calamine lotion or an over-the-counter topical corticosteroid cream according to the package directions to ease the itching

• Take an antihistamine to calm the allergic reaction