Chlorine rash is a red, itchy rash that appears within a few hours after swimming in chlorinated pools or hot tubs. The rash can be raised and scaly, and the skin may be swollen or tender. In some cases, hives also develop. Chlorine rash is caused when the skin becomes irritated by chlorine, and can usually be treated with over-the-counter hydrocortisone creams. It typically clears up within a few days.
Chlorine rash can happen whenever you've spent time in chlorinated water, like a pool or hot tub. It appears a short time after getting into the pool, or within a few hours after swimming. Itching is usually the first sign something is amiss. The skin can feel dry and scaly and may burn. Red bumps appear across any areas that were exposed to chlorine, but they don't always appear evenly across the skin. The bumps often crop up in patches. Your skin may also be red, swollen, or tender. In more severe cases, hives develop. Chlorine rash is not contagious. It can't spread from one person to another. And while you may have clusters of itchy bumps across your body, chlorine rash doesn't spread after the first day or so (provided you're staying out of the pool at this point).
Although it's sometimes called a chlorine allergy, you don't really have a true allergy to chlorine, but rather a sensitivity to it. Chlorine rash is a type of irritant contact dermatitis. Chlorine is a needed additive to keep swimming pool water sanitary and safe from microbes. Without chlorine acting as a sanitizer, the water in your pool or hot tub would get nasty in a hurry. Algae, bacteria, and viruses could quickly grow unchecked. But the downside is chlorine can be irritating to the skin, especially if you're exposed often. Chlorine strips the skin of its natural oil, called sebum. That's why your skin feels tight and dry after swimming, even if you don't develop a rash. When the chlorine levels in the pool are especially high, like just after cleaning or a chlorine shock treatment, you're more likely to develop a chlorine rash. But you can also develop a chlorine rash when chlorine levels are not particularly high. The sweat, skin oils, and, yes, urine in pool water react with the chlorine creating compounds called chloramines. Consider them the by-product of chlorine mixing with the oils and sweat on your skin. Chloramines are what give swimming pools and hot tubs their distinctive odor, and can be quite irritating to the skin. So, you can still develop a chlorine rash after swimming in pools where the chlorine level is low. Even if you rinse off after swimming, you may still develop a chlorine rash. Chlorine is extremely difficult to completely rinse off from the skin and hair. That's why you may still "smell like pool water" even after showering.
Who Gets Chlorine Rash
People who spend lots of time in the pool are prime candidates for developing chlorine rash. It's more likely to develop with repeated exposure, so you can get chlorine rash even if you've swum previously without issue. Swimmers aren't the only people who have to watch out for chlorine rash. If you simply take care of a pool or hot tub, you can develop it too. People who are responsible for putting chlorine into the pool may develop a rash if some of the chlorine gets into their skin. Some people are more sensitive to chlorine than others, so you can develop a rash while others who swam in the same pool don't. If you have eczema or psoriasis you may be more susceptible to developing chlorine rash, because your skin is already sensitized.
Other Rashes You Can get from Swimming
There are other rashes you can get from swimming beside chlorine rash. Although many of these are colloquially called swimmer's rash, they are different types of rashes with different causes.
- Hot tub folliculitis (AKA hot tub rash) also causes an itchy rash and pus-filled bumps. Unlike chlorine rash, though, the culprit is bacteria like Pseudomonas. Hot tub folliculitis tends to be worse in areas that were covered by your swimsuit. Hot tub rash usually goes away without treatment after a few days.
- Swimmer's itch, more precisely cercarial dermatitis, is caused by tiny parasites. You're not likely to get this after swimming in a pool that's properly maintained, but rather after swimming in rivers, lakes, and ponds.
- Seabather's eruption is caused by larvae that live in the ocean. You won't get this from swimming in pools.
- Bikini bottom causes red, inflamed, pimple-like bumps on areas covered by your swimsuit. It happens after sitting around in wet bathing suits for long periods of time, allowing bacteria to infect the skin's follicles. It should be treated with antibiotics.
Chlorine rash can be treated at home with over-the-counter medications. Most rashes will clear up after several days.
Over-the-counter hydrocortisone creams reduce the itching, redness, and swelling. You can get these at your local pharmacy or drugstore. They're sold under many brand names like Cortaid, Cortizone 10, or simply generic hydrocortisone. OTC hydrocortisone creams can be used two to four times a day. Apply a thin layer to the rash, and gently rub into the skin until it's fully absorbed.
- Topical Benadryl (diphenhydramine) creams are another over-the-counter option. They help relieve itching and irritation from the chlorine rash and can be quite soothing. Apply them up to four times a day to the entire rash area.
- Emollient lotions and creams help moisturize skin dried out by chlorine. You can use these in between applications of medicated creams if you need them. Choose a lotion that is fragrance-free and hypo-allergenic to avoid irritating your rash.
If you already have a chlorine rash, it can become more irritated the more you go into the pool. Consider taking a break from swimming or hot tub soaking for a while to allow your skin to heal. If you aren't getting relief with over-the-counter treatments, your doctor can prescribe stronger medications to help clear up your rash.
Along the same lines, you should see your physician about your rash if:
- You aren't sure if your rash was caused by chlorine.
- You have severe hives or hives that won't go away with treatment. Any severe allergic reaction warrants emergency treatment.
- Your rash isn't getting any better with home treatment.
- Your rash is spreading, getting worse, or seems severe.
The old adage an ounce of prevention is worth a pound of cure is particularly fitting when it comes to chlorine rash. Although you might not be able to completely prevent a rash—especially if you are very sensitive to chlorine or spend a lot of time in the water—these tips can help limit your chance of developing a rash.
- Rinse off prior to getting into the pool or hot tub. This helps rinse away sweat and oils on the skin that can react with chlorine, causing an irritating reaction.
- Shower immediately after coming out of the water, if your pool has shower facilities available. Just a simple rinse isn't enough to remove chlorine, though, so you should also follow up with a shower and soap as soon as you can, preferably with a gentle, non-drying soap or body wash. If you prefer, or you're especially prone to chlorine rash, you may want to try a post-swim chlorine removal body wash.
- Use post-swim chlorine removal spray if it's not possible to shower immediately after swimming. Look for one that contains vitamin C, as this helps neutralize chlorine.
- After showering, slather your skin with a gentle, fragrance-free lotion or cream to help moisturize and reduce dryness caused by chlorine.
- Don't sit around in a wetsuit or trunks. Shower and change ASAP.
- Some recommend applying a moisturizer, a very thin layer of petroleum jelly, or a pre-swim lotion to the skin 15 minutes or so prior to getting in the water. The idea is that this creates an extra barrier between your skin and the chlorinated water. Although this theory hasn't been proven, you may want to try it to see if it works for you.
- Monitor the chlorine levels in your pool or spa. Try to avoid getting them too high, and use test strips to measure chlorine levels before taking a dip. If you're swimming in a public pool, you obviously don't have control over how much chlorine there is or when it's added. But you can ask when chlorine is typically added and avoid swimming during those days since the chlorine levels will be higher, and stay out of the pool if you notice a very strong chlorine smell, as this means there are high levels of skin-irritating chloramines.
The only foolproof way to stop chlorine rash is to stay out of the pool. Obviously, that isn't always the best option. If you love swimming or are a competitive swimmer, you'll scoff at the notion to stay out of the pool.
If you're incredibly prone to chlorine rash and you absolutely do not want to give up swimming, you may consider converting your pool to a different type of sanitizing system, like saltwater or ultraviolet sanitizer. Converting your pool can be pricey and it may not be realistic in your case, but it may be something to look into if you are a die-hard swimmer prone to severe chlorine rash.
If that's not possible, talk with your doctor about things you can do to manage chlorine rash while continuing with your swimming.