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What is Hot Tub Rash? Causes and Prevention

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Hot tubs are a great way to relax and unwind. But if you’ve ever found your skin is itchy and red after being in one, you may be suffering from hot tub rash. This is a fairly common occurrence, but it is entirely preventable. In this article, I’m going to cover what hot tub rash is, what causes it, how you can alleviate the symptoms, and what precautions you can take to prevent it. 

What is Hot Tub Rash?

Hot tub rash’s scientific name is Pseudomonas folliculitis. It is a skin infection caused by a bacteria called Pseudomonas aeruginosa. 

A mild case will normally appear as small itchy red bumps, but more severe cases can cause pus-filled blisters. These bumps or blisters normally appear in areas which are covered by your swimsuit. 

I remember once staying at what was supposed to be a luxury hotel. I had had a long soak in the hotel spa, and a few hours later I developed a painful red rash on my thighs and backside. At first, I thought it might just be heat rash, but it kept getting itchier, and eventually, small pustules formed on my left thigh. That was my unpleasant introduction to hot tub rash. 

Luckily, I’ve never experienced it in my own hot tub, which is probably because the experience has made me extra diligent about taking the steps to prevent hot tub rash. 

Causes of Hot Tub Rash 

Pseudomonas aeruginosa, the bacteria which causes hot tub rash, loves warm, wet environments. Obviously, this makes hot tubs the perfect environment for it to thrive and multiply. However, there are certain things that can make Pseudomonas aeruginosa much more likely to survive in your hot tub: 

1. Contaminated Water 
If your hot tub water is not regularly cleaned, it can become a breeding ground for all sorts of bacteria, including Pseudomonas aeruginosa. Water without the proper levels of bromine and chlorine is much more likely to have Pseudomonas aeruginosa in it. 

2. Improper Maintenance 
Bacteria can grow in filters as well as water. If your filters are blocked, they are likely breeding grounds for lots of different bacteria. 

3. Individual Susceptibility 
Some people are more prone to skin infections. Unfortunately, I am one of them, I’ve had sensitive skin my whole life, and it’s one of the reasons I get so paranoid about bacteria in my hot tub.  

Symptoms and Diagnosis 

A hot tub rash usually appears as small, red, itchy bumps. Severe cases can cause pus-filled blisters and a burning sensation. It is often found on areas which are covered by your swing suit which means it is most common on things, buttocks, groin, and (for women) chest. 

It can take anywhere from an hour to a couple of days to occur but is most common within a few hours of leaving a hot tub. The couple of times I experienced it, I noticed it several hours later when I was in bed. 

Diagnosing hot tub rash is pretty straight forward, if you develop a rash within a few hours of being in a hot tub. You have hot tub rash! 

Prevention of Hot Tub Rash 

Personal hygiene and diligent hot tub maintenance are your best weapons against hot tub rash: 

1. Proper Maintenance of Hot Tubs: 

  • Regular Cleaning 
    Clean and disinfect your hot tub regularly. I make a point of scrubbing down the sides of the hot tub at least once a month, although I will do it more often if we have been using the hot tub a lot or had a lot of different people in it. 
  • Maintain Chlorine/Bromine Levels 
    Keeping the correct levels of chlorine and bromine for your size of hot tub is essential to stop bacteria from growing. Always use a test strip before you get in the hot tub and adjust the levels if needed. 
  • Water Changes 
    Regualry change the water in your hot tub. Stagnant water is a breeding ground for all sorts of bacteria. 

2. Personal Hygiene 

  • Shower Before and After 
    Always shower before and after you use a hot tub to minimize the risk of contamination. Make sure all your guests follow this rule too. 
  • Avoiding Hot Tubs with Open Cuts 
    Do not use your hot tub of you have cuts, or open sores. Wait until you are fully healed before going in the hot tub. 

Treatment Options 

If you are unfortunate enough to end up with hot tub rash, there are some steps you can take to reduce the severity of the symptoms. 

1. Over-the-counter Treatments 
Anti-itching creams and antihistamine ointments can help to manage the immediate symptoms and reduce your skin’s reaction to the bacteria. I tend to combine a hydrocortisone cream and taking an oral antihistamine. Always follow the instructions on the medicine packaging and never take more antihistamines than recommended by the manufacturer. 

2. Home Remedies 
Cool compresses, or even a bag of frozen peas, can help to soothe your skin’s itching. Oatmeal baths can help with particularly severe cases.  

3. Don’t scratch 
I know this is probably the hardest one to do, but try not to scratch at your rash, no matter how itchy it is. It will only make it worse. 

4. When to See a Doctor 
If your rash lasts more than a couple of days, or if you start developing other symptoms like a fever, or the rash appears to be spreading – you should see a doctor. 


Hot tub rash is very irritating, and if you are unlucky enough to have it you might be in for a couple of days of annoying itchiness, but it is rarely dangerous. 

If you’re reading this while itching, just think of this as a learning experience to improve your hot tub maintenance and personal hygiene. 

Avoiding hot tub rash isn’t hard, it just requires you to be diligent. Remember to follow the steps in this article to prevent future occurrences, especially if you have guests using your hot tub. Nobody wants to be known as the neighbor who gave everyone a rash.