PENSACOLA — Purple flags appeared on Pensacola Beach this week as lifeguards warned of a stinging pest that is leaving beachgoers with a red, itchy rash and what could resemble a jellyfish sting.
Sea lice are the tiny larvae of marine life such as jellyfish and coral. These small pests can get caught in the clothing of swimmers, and contact with the skin can produce a sting through nematocysts, or small stinging structures that burst upon contact, according to the Florida Department of Health.
Sea lice are often reported between the months of March through August and are prevalent along 250 miles of Florida beach, from the southern Atlantic coast to the Florida Panhandle.
Their stings can cause a red, itchy rash, also known as sunbathers eruption, that begins to appear around 4 to 24 hours after exiting the water. Some swimmers report feeling a slight prickling sensation while still in the water.
The name "sea lice" is technically a misnomer as real sea lice are a parasite that only affect fish. But the nickname took hold in the 1950s before full research was done on the cause of the itchy beach rash.
In Pensacola, the lifeguards began warning visitors of the itchy menace — which are the size of grains of black pepper and float on the water's surface — on Monday, raising purple flags and announcing the sighting on on their Facebook page.
In Pinellas County, the Florida Department of Health does not monitor for sea lice. Spokeswoman Maggie Hall said sea lice are pests that beachgoers should be aware of but have to accept.
"It's one of those things that live in the water and we encourage people to shower off and wear their swimsuits and not to wear shirts in the water," Hall said. "It's not anything we have tests for. It's just one of those things that you have to deal with."
Instead, Hall said, the department consistently tests 10 of the most popular beach spots in Pinellas for harmful bacteria and disease. Since sea lice do not spread infectious disease, they are relegated as simple pests.
The Florida Department of Health recommends using over-the-counter hydrocortisone cream to treat the rash. Calamine lotion or colloidal oatmeal cream can be used to calm the itch. Swimmers should shower before leaving the beach.