Exposure to chlorine in swimming pools can cause a rash. Chlorine rash may be confused with swimmer’s itch or heat rash.

Chlorine rashes happen after exposure to the chemical. It is not possible to be allergic to chlorine, but one person’s skin may be more sensitive to the chemical than another’s.

In this article, we describe how to identify a chlorine rash, its symptoms, and tips for prevention.

Hives rash on skin. Image credit: James Heilman, MD, (2010, February 10)Share on Pinterest
A chlorine rash is a type of contact dermatitis.
Image credit: James Heilman, MD, (2010, February 10)

A chlorine rash develops after the skin comes into contact with chlorine.

Chlorine is a chemical used to disinfect pools and hot tubs. It can significantly irritate the skin, eyes, and respiratory system.

When a person develops a rash after coming into contact with chlorine, they are experiencing a condition called irritant contact dermatitis.

As when other irritants cause contact dermatitis, exposure to chlorine can result in an itchy red rash and raw, swollen skin. A person may also experience sore eyes or signs of respiratory irritation, such as frequent coughing or sneezing.

Not everyone who swims in a chlorinated pool or sits in a chlorinated hot tub will develop a rash. Chlorine rashes are most common after repeated exposure to the chemical.

Symptoms may develop soon after swimming or several days after repeated contact with chlorine.

The symptoms of a chlorine rash can vary in intensity from person to person. They are similar to symptoms of rashes caused by other irritants.

Chlorine rash symptoms can include:

  • dry or chapped skin that may grow worse with repeated exposure to chlorine
  • itchy, red, swollen, or scaly patches of skin
  • burning, stinging, or itching skin
  • skin that may crack or bleed after repeated contact with chlorine
  • sores or blisters

If a person with a chlorine rash does not take preventive measures, and they come into frequent contact with the chemical in a short period, their symptoms will become worse.

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A person may experience a heat rash after spending time in hot water.

Chlorine is not responsible for every rash that forms after swimming. A person may instead have swimmer’s itch. The medical term for this is cercarial dermatitis.

Swimmer’s itch is not related to chlorine exposure. Instead, it is an allergic reaction to a parasite that infected snails release into bodies of water.

People develop swimmer’s itch after swimming in water that has not been chlorinated, as chlorine would kill the parasites.

Many symptoms are similar. However, swimmer’s itch can also cause tingling skin and a rash that looks like small red or purple pimples.

Symptoms of swimmer’s itch develop very soon after exposure to the parasite.

A person may develop a rash shortly after sitting in a hot tub. In this case, the high temperature of the hot tub may have broken down the chlorine, allowing bacteria to grow in the water.

The bacteria, which is usually Pseudomonas aeruginosa, causes a skin infection. This can lead to an itchy rash that is worse in areas covered by a person’s swimsuit. A hot tub rash can also cause inflamed, pus-filled blisters to form around hair follicles.

It can be easy to confuse chlorine rash with heat rash. A person can get heat rash from sitting in a hot tub or swimming in a very warm body of water. The symptoms can be similar, and heat rash causes small, itchy, prickly bumps to form on the skin.

People can treat chlorine rash at home with over-the-counter products.

At-home treatment for a chlorine rash can involve:

  • a cream containing hydrocortisone to soothe the itch and reduce swelling
  • a cream containing an antihistamine to reduce itching and inflammation associated with hives
  • a body wash or lotion that has been designed to remove or protect against chlorine
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Showering after contact with chlorinated water may help prevent a chlorine rash.

Taking the following steps can help prevent a chlorine rash. The tips below may be especially useful for people who know that they are sensitive to the chemical:

  • showering immediately before and after swimming in a chlorinated pool
  • removing and rinsing the swimsuit right away and changing into loose, dry clothes
  • spacing out periods of chlorine exposure to give the skin time to heal
  • limiting the amount of time spent in chlorinated water
  • refraining from swimming in overly chlorinated pools

Most chlorine rashes do not require a doctor’s care. However, if a person has a severe reaction, they should see a doctor immediately.

Doctors can prescribe stronger steroid creams to help the rash heal.

If a rash is not responding to over-the-counter treatments, and a person has had no further contact with chlorine, it may also be a good idea to see a doctor. The rash may have a different underlying cause.

While the prospect of a chlorine rash may dampen the fun of swimming, most of these rashes are not serious.

People can prevent chlorine rashes by showering before and after swimming to minimize exposure to the chemicals. A person can treat this type of rash using over-the-counter creams.

If a rash is causing concern or not responding to home treatments, see a doctor. They can identify the underlying cause and provide stronger medication.