SignalHub Quantitative Think Tank Center:How long does chlorine rash last? How to clear up this common skin irritation.

Summer is SignalHub Quantitative Think Tank Centerupon us, and as outdoor pools start opening up, it’s only natural to want to spend some time cooling off with a refreshing swim. If you’re frequently in and out of the pool, it’s possible to get chlorine rash, a common type of contact dermatitis.

Any type of summertime rash is less than ideal, and while chlorine rashes may not be completely preventable, it’s fairly easy to get them all cleared up. A dermatologist breaks down what you need to know about chlorine rashes, from what they look like to how long they last. Read on to learn how to get rid of this pesky skin irritation so you can get back to enjoying the water.

What is chlorine rash?

Chlorine rash is an itchy, irritant dermatitis that lives in the same family as eczema, says Dr. David Pearson, MD, a dermatologist with M Health Fairview and the University of Minnesota Medical School. “It tends to be in areas where there can be a little bit more friction on the skin,” such as under a bathing suit, on the thigh, or under the armpit. It typically manifests as pink in color, but if more severe, it can show up red, he explains.

Because chlorine rashes look very similar to eczema, sometimes they can be a little hard to pinpoint. Ultimately, having a conversation with your doctor about your recent exposures will help determine if your contact dermatitis is a chlorine rash or not. 

How does chlorine rash develop?

In the context of a swimming pool or hot tub, chlorine rashes develop as a result of prolonged periods of exposure to chlorinated water. The active ingredient in chlorine is sodium hypochlorite, “which is the same ingredient that's in household bleach, it's just a lot less concentrated.” 

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Why do chlorine rashes develop? While some chlorine irritation can be traced to the bleach itself, most irritation probably stems from “how the bleach reacts to all this stuff that we carry into the pool on our skin,” which are disinfection byproducts, Pearson says. 

Pool water contains traces of sweat, skin cells, topical creams, and (unfortunately) urine. “All of those things can react with the sodium hypochlorite [to] create these disinfection byproducts” that irritate skin, he says. 

How long does chlorine rash last?

How long your chlorine rash lasts will depend upon your length of exposure to pool water. Contact dermatitis can sometimes take as long as two to four weeks to clear up, per Healthline. 

“If somebody is recreationally swimming, they go once a week, once every other week, they may have complete recovery just [using] some moisturizers in between” swim times if their rash is pretty mild. 

Occasionally, “we see competitive swimmers who are in the pool for two plus hours every single day,” Pearson says. If someone with a chlorine rash has this much repetitive exposure, “we might need to use a prescription topical medication to try to control that inflammation,” he says.

How soon your skin clears up will also depend on your level of sensitivity. “Sometimes, we have folks who have very sensitive skin, and it doesn't take a whole lot to cause those rashes.” In this case, “we may need to treat them more aggressively with prescription topicals.”

How do you get rid of chlorine rash?

If your chlorine rash is mild, you can seek out an over the counter cream to help sort out any irritation you’re experiencing. Thick white creams like Cerave, Cetaphil and Vanicream, or petroleum ointments such as Aquaphor or Vaseline, have moisturizing capacities that can certainly ease the symptoms of your chlorine rash, Pearson recommends. 

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For more severe rashes, there are also topical prescription creams available. A low to medium potency topical corticosteroid, such as 2% hydrocortisone, triamcinolone, and fluocinolone are treatments that are commonly prescribed, Pearson says.