Hard water may damage the skin barrier, which can cause your skin to become dry and irritated.
When water contains high levels of calcium and magnesium, it’s described as hard water. This can occur as water filters through underground limestone, gypsum, or chalk. The local water supply in some communities is hard.
Some evidence suggests that hard water may damage the skin barrier and contribute to the development of eczema. This is a chronic condition that causes inflamed, irritated, and itchy skin.
Hard water might also worsen symptoms of eczema in people who already have the condition.
Read on to learn more about the effects that hard water may have.
“Skin barrier dysfunction is the initial step in the development of eczema,” Soma Mandal, MD, a board certified internist at Summit Health in Berkeley Heights, New Jersey, told Healthline.
The skin barrier is the outermost layer of the skin. It helps keep out bacteria, viruses, allergy triggers, and other harmful substances. It also seals in water, which helps to keep the skin moisturized.
When the skin barrier is damaged, it lets in germs and other substances more easily. The skin also loses moisture, causing it to become dry and damaged.
Gene mutations and problems with the immune system may alter the skin barrier. Exposure to certain substances, such as irritating soaps or hard water, might also damage the skin barrier and raise the risk of eczema.
The authors found that young children who were exposed to hard water had an increased risk of developing atopic eczema. More research is needed to study and confirm this link.
Small studies in adults also suggest that hard water may:
- reduce skin hydration
- increase skin redness
- increase the level of cytokines, which are proteins that drive inflammation
According to the review’s authors, research in mice has found that applying calcium to the skin may lower its ability to repair after damage.
Minerals in hard water lower the pH of the water. Bathing in hard water may affect the pH of the skin, which can affect how the skin barrier works.
Calcium and magnesium ions in hard water also bind to certain particles in soap, known as surfactants. This makes it harder to rinse soap away, causing a residue or “soap scum” on the skin.
This can damage the skin barrier and irritate the skin, report researchers in the Journal of Investigative Dermatology.
Eczema can affect people of any age. However, it’s more common in young children.
Eczema often goes away by the time children become teenagers. However, some people experience eczema as teenagers or adults.
Seborrheic dermatitis is also known as seborrheic eczema. It mainly affects the scalp and is one of the possible causes of dandruff.
Seborrheic dermatitis may also affect other parts of the body that have many oil-producing glands, such as the:
- upper chest
Calcium and magnesium ions in hard water make it harder to rinse off soap and shampoo, causing a residue to form on the skin or scalp. This may worsen seborrheic dermatitis.
To treat eczema, your doctor may prescribe:
- a medicated skin cream, ointment, or shampoo
- phototherapy, which uses ultraviolet light waves to reduce symptoms
- oral or injectable medication to block immune responses that cause inflammation
Oral or injectable medications are only used to treat severe eczema.
Your doctor may also recommend changes to your skin care routine. For example, it may help to:
- Avoid scratching or rubbing your skin.
- Use gentle, unscented soaps or cleansers.
- Bathe with lukewarm water rather than hot water.
- Gently pat your skin dry after bathing rather than rubbing it dry.
- Apply a moisturizing cream or ointment to your skin after bathing.
- Avoid scented skin care products, scented laundry detergents, rough clothing, or other triggers that seem to make your symptoms worse.
Soaps that contain fragrances or dyes may irritate your skin. Bar soaps, bubble baths, and baby wipes may also irritate or dry.
“Typically, products that are free of dyes and perfumes are best for the skin,” said Mandal.
Dermatologists recommend mild, unscented cleansers and other fragrance-free skin care products.
The American Academy of Dermatology Association encourages people with eczema to look for products labeled with the NEA Seal of Acceptance. These products are free of unsuitable ingredients for people with eczema or sensitive skin.
Some studies suggest that hard water may increase the risk of eczema or worsen symptoms, though more research is needed.
Hard water may damage the skin barrier, which causes the skin to become dry and irritated. Scented soaps and other scented products may also irritate the skin.
Dermatologists typically encourage people with eczema to use gentle, unscented cleansers and moisturizers. Doctors may also prescribe medicated creams or ointments, phototherapy, or other treatments for eczema.