Sea Lice is also known as Sea Bather's Eruption or Pica-Pica.
Sea lice generally occur on the lower Atlantic coast of Florida from March through August, with the highest incidence in May and June. I have not heard of them being a problem on the Gulf coast at all. Sea lice create an itchy red rash on areas of the body covered by a bathing suit. But, sea lice are really not lice at all. They are the larvae of the Thimble Jellyfish. The nearly microscopic larvae become trapped between the bathing suit fabric and the skin. The resulting friction activates the larvae’s stinging mechanism. The stinging mechanisms are called nematocysts, like those of a jellyfish.
Symptoms of Sea Lice (Jellyfish larvae )Stings
On first exposure, while still in the water, a bather may experience a tingling sensation on areas of the body covered by swimwear. Hairy underarms and hairy chests are also affected.
During the next few hours an itchy red rash develops. The itch can last for several weeks. The rash is the body's reaction to the jellyfish venom, or toxin injected by the nematocysts.
Some people may develop a fever or feel unwell and tired. Children are more likely to develop systemic effects like fever, nausea, abdominal pain, and diarrhea.
Treatment of Sea Lice (Jellyfish larvae) Stings
After showering, applying diluted vinegar or rubbing alcohol to the skin may help neutralize any remaining toxin from the stinging nematocysts. Hydrocortisone lotion or cream and antihistamines may also help.
Prevention of Sea Lice (Jellyfish larvae )Stings
- The best prevention is to avoid going swimming along the lower southeast coast of Florida during the early summer months, particularly May and June.
- Pay attention to signs posted on the lifeguard towers warning of sea lice in the water.
- Wear as little clothing as possible while swimming in water that may have sea lice.
- When swimming in water with sea lice jellyfish it is most important to remove the bathing suit as quickly as possible. As the fabric dries and the skin rubs against it, more stings will occur. Do not shower with the “contaminated” suit on. The fresh water will cause the nematocysts to sting even more.
- Remove the suit and shower under forceful water to rinse off any larvae that may be clinging to the skin. Rinsing in salt water that is free of larvae is the best way to rinse, but it doesn't seem likely that such could be easily found.
- The contaminated suit should be machine-washed in hot soapy water, and dried in a hot drier. A hand rinsed and air dried suit may still contain active larvae.
- Different people are affected to different degrees. I went swimming off Miami Beach a few years ago with some friends during the last week in May. One of them developed a significant rash. I only had a few stings. Another friend had no effects at all. A person’s immune system seems to have an important role in the severity of the reaction an individual may experience.
I've never encountered sea lice on the Gulf coast, but that doesn't mean others haven't.