Does hot water worsen seborrheic dermatitis?

There is nothing more soothing than a burning hot shower when you have an itch but you’ll always find that your rash looks and feels worse after.

As much as you would like to convince yourself that something that feels so good cannot be bad for you, you know deep down that hot water worsens seborrheic dermatitis.

Why has nature been so cruel to you? What could be worse than having seb derm and losing the freedom to have a hot bath or shower whenever you want? (I can actually think of 10 things right of the bat that’s worse than this combo but bear with me as I give in to my inner drama queen).

In a nutshell, hot water strips your skin of its natural oils, damages your skin barrier and increases symptoms of seb derm. So what should you do instead? Take a cold shower? Have an ice bath? Yucks. 

Let’s find out:

Hot water damages the skin barrier

Prolonged exposure to water at any temperature can strip the skin of its natural oils and damage skin barrier, especially when the water is hot. A study on 50 healthy volunteers found that when they were immersed in water at 44 degrees celcius, transepidermal water loss (a marker of damaged skin barrier) and erythema (redness) increased.

Imagine what hot water does to skin that is already inflammed by seb derm.

Further reading: Impaired skin barrier in seborrheic dermatitis

Hot water increases histamine release

Heat (temps above 42 degrees) activates our skin TRPV1 proteins and induces histamine release, which ultimately leads to itching.

In fact, after this can reduce the temp treshold for activation of TRPV1 and cause thermal hyperalgesia. This is a situation where comparatively low temperatures can induce itch.

Hot water dries the skin and increases sebum production

Hot water can strip the natural oils from both the superficial layer and deeper layers of the skin. This leads to dryness and an increase in sebum production as the skin tries to compensate.

The result is an increase in food for malassezia (the yeast that causes seborrheic dermatitis and dandruff) redder skin due to dilated blood vessels opening up pores, and an increase in inflammatory processes.

Hot water worsens redness

Having a hot shower or bath increases blood flow to the skin, causing vasodilation (widening of blood vessels) and increasing skin erythema (redness). You may find your rash looking much redder or blotchy for 1-2 hours after your shower.

This doesn’t mean your seb derm got worse, but it definitely looks worse. The redness generally settles after a few hours when your skin cools down.

Hot water can worsen dandruff

When you combine hot water with shampoos full of chemicals that can also damage the skin barrier, it can be hard on the scalp, leaving it dry, itchy and flaky.

It’s worse when you live in an area with hard water.

Further reading: hot water seborrheic dermatitis

Can hot water cause seborrheic dermatitis?

We know hot water can exacerbate seborrheic dermatitis but does it cause seb derm?

No, hot water does not cause seborrheic dermatitis if you don’t already have it. It’s very rarely the trigger for seb derm. Even repeated hot showers of a long period of time does not cause seborrheic dermatitis.

Do cold showers help seborrheic dermatitis?

Cold showers have lots of skin and health benefits including improvement of cardiovascular health, strengthening of the immune system and anti-aging effects. Yes, anti-aging!

There is no clinical evidence to suggest that cold showers improve seborrheic dermatitis. However, we can safely predict that theoretically, cold showers can improve our rash, even if it’s for a few hours.

Cold water reduces inflammation, relieves itch and soothes the skin. It also constricts blood vessels, which may help to reduce redness and swelling in the affected area. Cold water can also help to tighten pores and reduce oil production.

It’s such a shame that they are a pain to take, especially on a cold winter morning.

A good alternative to hot showers

While you may not be in a hurry to have an ice bath, having a lukewarm shower or bath is a good compromise. Lukewarm water won’t shock your skin one way or the other and is the safest (and most comfortable) temperature to shower in.

What’s the definition of lukewarm? The same temp range as your body – between 36.5 and 40.5 degrees celcius (98 to 105 Farenheit).

Happy lukewarm bathing!