All Topics
Eczéma et eau de mer.

Eczema and sea water: good or bad idea?

Known for its high salt concentration, seawater is often associated with drying effects on the skin. However, it also offers several benefits for the skin. What about for those with eczema? Is seawater suitable for this condition?

Published October 11, 2023, updated on February 8, 2024, by Pauline, Head of Scientific Communication — 5 min read

What exactly is eczema?

Eczema is a chronic inflammatory skin condition that primarily affects infants, children, and adolescents. However, it can also manifest in adults. Theeczema is characterized by red, rough, and very itchy skin lesions, which can appear on different parts of the body. This skin disease is very common and ranks just behindacne in terms of prevalence.

Individuals suffering from atopic eczema produce high amounts ofimmunoglobulin E (IgE) in response to allergens present in their environment. This condition is also caused by a dysfunction of the skin barrier, resulting from a decrease in the production of sebum, lipids, and cell adhesion molecules. Consequently, the skin's protective barrier is compromised, allowing allergens to penetrate more easily. Moreover, eczema can also be acquired and not linked to genetic factors, in this case, it is referred to as a contact eczema triggered by a specific allergen.

To alleviate eczema flare-ups, dermatologists typically prescribe topical corticosteroids, emollient creams containing cortisone, which help restore the skin barrier while reducing itching and redness, thanks to their anti-inflammatory properties. In addition, it is possible to use natural remedies.

A preventive effect of seawater on eczema?

There are reasons to believe that seawater may have a preventive effect on eczema. This is, at least, the conclusion of a recent study conducted on rats. In this study, eczematous lesions were induced in the rats following the application of a 1% solution of 1-chloro-2,4-dinitrobenzene, an irritant agent, over several days. Following this, filtered and concentrated seawater was applied five times a week for six weeks to half of the rats.

Following this experiment, researchers observed that the severity of lesions in rats that did not receive the sea water treatment was almost twice as significant as those that did receive the treatment. Additionally, measurements of TEWL, that is, the transepidermal water loss, showed that the "sea water rats" lost approximately 25 g/m2.h of water compared to 35 g/m2.h for the untreated rats. This TEWL is typically around 10 g/m2 .h for these rats. The application of filtered sea water did not reach this value but still had a certain protective effect.

Finally, immunological tests have shown that the "sea water" mice had higher levels of interleukins 4 (IL-4) and interleukins-10 (IL-10), pro-inflammatory cytokines, compared to untreated mice. These compounds play a role in various inflammatory processes, such as the development of redness or lesions.

Key Takeaway : A study has shown that the application of seawater following the induction of eczematous lesions in rats helped to limit the severity of the lesions, suggesting a preventive effect of seawater on eczema. However, it is important to note that this experiment was conducted on rats, not humans, and that filtered seawater was used.

A therapeutic effect of seawater on eczema?

Seawater has been used for decades for its therapeutic virtues on the skin. In fact, it is the foundation of thalassotherapy. As for eczema, it appears that sea water may also be beneficial. A study examined the effect of applying sea water to eczematous lesions located on the forearms of willing participants. These lesions had been induced by an irritating solution of sodium laureth sulfate.

Measurements of TEWL, or Transepidermal Water Loss, were used to assess the effectiveness of the epidermal barrier. These showed that the application of seawater had a protective effect on the skin barrier and partially inhibited the irritation caused by sodium laureth sulfate. It is hypothesized that this effect is due to the minerals present in seawater, particularly sodium chloride NaCl, which, thanks to its hygroscopic properties, may have contributed to maintaining the hydration of the epidermis.

Key Takeaway : A study has shown that seawater has beneficial effects on eczematous skin. However, it's important to note that one should not bathe in seawater when wounds are open, as this could further irritate them. Instead, sea baths can soothe the skin between flare-up periods.


  • MAIBACH H.-I. & al. Sea water or its components alter experimental irritant dermatitis in man. Skin research and technology (2001).

  • KIM E.-H. & al. Application of concentrated deep sea water inhibits the development of atopic dermatitis-like skin lesions in NC/Nga mice. BMC complementary and alternative medicine (2012).

  • SAURAT J. H., LACHAPELLE J. M., LIPSKER D., THOMAS L. et BORRADORI L. Dermatologie et infections sexuellement transmissibles. Elsevier Masson (2017).


Understand your skin
and its complex needs.