What is Swimmer’s Itch and How to Treat This Common Summertime Rash
Swimmer’s itch is a rash caused by an allergic reaction to the larvae of microscopic parasites found in both fresh and saltwater. These parasites commonly live in snails, which release larvae into the water, according to the CDC. Swimming in contaminated water, even briefly, can result in swimmer’s itch. After contact with the larvae, “when the skin dries off, those parasites burrow under people’s skin and cause an itchy rash,” explains Dr. Christina Boull, an associate professor of dermatology and pediatrics at M Health Fairview University of Minnesota Medical Center. Here’s what symptoms to look for and precautions to take to prevent this uncomfortable summertime rash.
What is Swimmer’s Itch?
Swimmer’s itch, also known as cercarial dermatitis, is characterized by small red dots that appear on your skin after exposure to the parasites, says Dr. Boull. The rash typically appears on skin directly exposed to the water, such as arms and legs, rather than areas covered by a bathing suit. These dots usually show up about 12 hours after exposure, and within a day or two, some individuals may develop a more severe reaction with welts and blisters. One main risk factor of complication from this rash is a secondary bacterial infection. Scratching the rash can introduce staph bacteria under your skin, potentially leading to staph infections like impetigo or cellulitis.
What Can Be Mistaken for Swimmer’s Itch?
Seabather’s eruption is a rash that presents similar symptoms to swimmer’s itch but tends to develop under a swimsuit. Swimmer’s itch, on the other hand, is more likely to appear on skin not covered by a swimsuit. Additionally, because swimmer’s itch manifests as small red bumps, it is often mistaken for bug bites from gnats or mosquitoes.
How Do You Get Rid of Swimmer’s Itch?
“The good news is that it spontaneously resolves,” says Dr. Boull. Humans are not the preferred hosts for the parasites, so they don’t remain in the skin very long. The rash and itching usually improve within a week, though it can last up to three weeks. To relieve itching, Dr. Boull recommends using 1% hydrocortisone, an over-the-counter topical steroid cream, and taking an oral antihistamine. For severe itch, prescription oral prednisone and cortisone can help. If the rash develops into blistering, open sores, or is accompanied by a fever, it may indicate a secondary bacterial infection, and you should see a doctor for oral antibiotics.
Does Showering Prevent Swimmer’s Itch?
The parasites that cause swimmer’s itch can only burrow into your skin after you’ve dried off. “So, it’s really important after getting out of a lake or areas where you’re swimming that have snails, to take a towel and really wipe the water off your skin.” Showering immediately after exiting the water can also help prevent the parasites from penetrating your skin.