What to Know About a Chlorine Rash?

Medically Reviewed by Mahammad Juber, MD on August 09, 2022
5 min read

A chlorine rash may occur due to the chlorine that’s put in swimming pools and hot tubs to kill bacteria. 

In this article, we will explore the related symptoms, causes, and possible means of prevention.

Chlorine is an inorganic chemical that’s used to prevent the growth of microorganisms in the water in swimming pools and hot tubs. It’s usually added at extremely low concentrations to kill the bacteria and disinfect the water that’s used by several people.

When used in full concentrations, chlorine can burn your skin. As the chlorine concentration found in swimming pools is very low, it typically only leads to skin irritation when there is contact for a long time.

The chlorine concentration in swimming pools is supposed to be maintained at levels that are harmless to the general population, but it can cause irritation in some instances.

When people who are sensitive to chlorine come in contact with it, they may get itchy red skin. In some cases, they may also get hives (bumps on their skin).

This is called irritant dermatitis and is very similar to a chemical burn.

Keep in mind that this reaction to the chemical is not immune-mediated. This means that it’s not a reaction that’s triggered by the immune system, but rather, is only an effect of the chemical on your skin due to its sensitivity.

This reaction is mostly observed in people who are constantly in the pool, such as lifeguards, professional cleaners, and swimmers who have spent over 1,000 hours in the pool.

Chlorine also dries the skin and can irritate existing cases of dermatitis. It may aggravate existing allergies by increasing the sensitivity of the respiratory tract.

Another factor that contributes to increased sensitivity is the presence of cleaning agents in the water which may contain chemicals that affect the respiratory system.

Research has shown that spending more time in swimming pools, especially those that contain chlorinated water, leads to an increased risk of asthma and other respiratory allergies in adolescents and adults.

That being said, there have been many instances where individuals who have reported chlorine sensitivity have gone on to achieve great heights in the pool. Some of the shining examples are the U.S. Olympic gold medallist Amy Van Dyken and five-time gold medallist Ian Thorpe from Australia.

Some people may get a rash after coming into contact with the chlorine in the water. Although you can’t be allergic to chlorine, your skin may be more sensitive to this chemical than others, which is why you may get a rash.

The severity of the rash is determined by the specific concentration of the chemical and also by the sensitivity of the individual who has come in contact with it. Other environmental factors such as the level of humidity and temperature also affect the intensity of the rash.

Instances of chlorine rash are generally believed to diminish following reduced contact with chlorine. On the other hand, sensitivity may escalate if the concentration of chlorine in the swimming pool or hot tub is increased.

Those in charge of maintaining the swimming pool tend to increase the chlorine concentration in response to public health concerns such as an outbreak of swine flu or increased levels of E. coli in the water. At such times, it’s better to switch to swimming pools where the chlorine levels are lower.

One good thing is that chlorine rashes are not contagious, so even if you get one, you can't pass it on to someone else.

If your skin is sensitive to chlorine, you may get any of the following symptoms:

  • Skin redness
  • Tender skin
  • Skin inflammation
  • Itchiness where chlorine has come in contact with your skin
  • Lesions (wounds in the skin) 
  • Flaky skin or crusts on the skin

If you have asthma, allergic rhinitis, or other lung conditions such as exercise-induced broncho condition (EIB), you may also experience some of the following symptoms:

  • Breathing issues
  • A constricted feeling in the chest
  • Runny or stuffy nose
  • Frequent sneezing
  • Frequent coughing, especially when you laugh, sleep, or exercise
  • Itching
  • Persistent wheezing, with a shrill noise that is similar to whistling

If you feel uncomfortable in water that contains chlorine, check with your doctor or an allergist. They may ask you to perform some tests to check your symptoms and determine the next course of action.

If you notice your skin reacting to chlorine, the first thing to do is to wash the area with clean water that doesn’t contain chlorine to remove chemicals that your skin is sensitive to.

Your doctor may also prescribe a corticosteroid to treat the affected area. In some cases where hives form on the skin, doctors may also prescribe antihistamines. If you have a history of asthma, allergic rhinitis, or EIB, let your doctor or allergist know before you get into water that contains chlorine.

If you have asthma, you may notice that when you get into a pool or a hot tub with chlorinated water and take a deep breath, there’s a burning sensation in your lungs. You should report such occurrences to your doctor.

If you think you’ve developed a sensitivity or an allergy to chlorine, there are a few things you can do to limit its impact and continue swimming.

Ask your pool operator about how they manage the pool and the chlorine levels they maintain. According to the Centers for Disease Control and Prevention (CDC), public pools should maintain a pH level between 7.2 and 8 on a scale of 1 to 14.

The lower the pH, the higher the acidity. A pH closest to 7 means that the pool is neutral and less reactive. The CDC also recommends maintaining the concentration of free chlorine at one part per million for swimming pools and three parts per million for hot tubs and spas.

Many pools ask swimmers to take a shower before entering the pool. While this measure is aimed at maintaining pool hygiene, it can be even better to take a shower after you’ve finished your stint in the pool.

Showering after you’ve finished swimming will remove any trace chemicals and prevent them from drying out on your skin.