Swimming in the ocean can leave you invigorated and refreshed, but it also can leave you with itchy skin. A number of parasites and even certain types of seaweed can be lurking about, waiting to bite, sting, infest or otherwise infect you. The only surefire prevention is avoiding the ocean altogether, although it can help to be aware of what you may encounter.
Swimmer's Itch
Swimmer's itch is an allergic reaction to microscopic parasites that can burrow into your skin. The parasites initially come from infected birds and other animals that pass the parasite eggs through their feces. If the eggs hatch near water, the larvae swim through the water searching for a particular type of snail which the larvae infect as they further develop into a type of larvae called cercariae. Cercariae leave the snails in search of their preferred animal hosts and will attempt to infect humans if they run across them. The parasites do not live long in a human, but their brief stay can come with itchy skin, a burning or tingling feeling and small red pimples and blisters.
Sea Bather's Eruption
Sea bather's eruption results in a rash, but this one hits areas that were covered by your bathing suit. Larval forms of thimble jellyfish and other particular anemones are to blame. The rash results as an allergic reaction to the poison that comes from the larvae's stinging cells. The larvae can become trapped beneath your suit and the stinging mechanism triggered by outside pressure, such as your suit pressing against your body while swimming or when you get out of the ocean and the water inside the suit drains out. The rash, which often starts as a tingling feeling, can be accompanied by fatigue and fever.
Other Causes
Sea lice and seaweed dermatitis can lead to itchy skin after swimming in the ocean. Sea lice come from flatworm larvae biting exposed skin while seaweed dermatitis comes from exposure to a poisonous type of seaweed. Both appear similar to and are sometimes confused with sea bather's eruption, although sea lice generally affect exposed skin and seaweed dermatitis only occurs in the presence of seaweed.
Remedies
Over-the-counter anti-itch creams and cool compresses or ice packs can help stop the itching and pain for any itchy skin conditions. Swimmer's itch treatment can also include corticosteroid cream, bathing in colloidal oatmeal, baking soda or Epsom salts. For sea bather's eruption, dabbing your skin with diluted rubbing alcohol or vinegar helps neutralize toxins left behind. Immediately removing your suit and showering is a must, as is washing your suit in a diluted vinegar or alcohol mixture and rinsing well. Calamine lotion and ibuprofen can also be helpful to soothe skin, reduce swelling and pain from itchy skin conditions. If nothing helps or your condition gets worse, your doctor can suggest other remedies.
