Swimmer's itch causes temporary bumps or blisters.
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Swimmer's itch (cercarial dermatitis) is a burning or itchy rash caused by an allergic reaction to waterborne parasites that burrow into the top layer of skin. The parasites soon die, but you're temporarily left with tiny bumps or blisters.

Swimmer's itch isn't serious and usually clears up on its own in 7 to 10 days. At-home remedies — soothing lotions, lukewarm baths with Epsom salts or baking soda — may ease the itchiness. You might also control the symptoms with antihistamines or anti-itch creams.

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