Key takeaway

  • Sweat can trigger eczema flare-ups because it can dry out the skin and leave behind substances like sodium that irritate sensitive skin.
  • To manage eczema when sweating, it is important to moisturize skin, stay hydrated, wear breathable clothing, and rinse off sweat as soon as possible.
  • Certain conditions, like heat rash and hyperhidrosis, can also affect sweat production and irritate the skin, potentially worsening eczema symptoms.

Sweat has natural moisturizing properties in people without eczema. However, it can irritate and dry out sensitive skin in those with this condition, worsening itching.

Sweat can leave a residue of substances that can dry out the skin and trigger an eczema flare-up for some people.

In this article, we look at the link between eczema and sweat, tips for managing sweating with eczema, and other treatments.

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According to the National Eczema Association (NEA), sweat can trigger flare-ups in people with eczema.

Sweat helps control body temperature — as it evaporates, it cools the skin. It also contains properties that naturally moisturize the skin. However, sweating can increase fluid loss in people with eczema and make their skin drier. The sodium in sweat can also increase itching and stinging.

Sweat mainly consists of water, urea, lactate, and minerals. A buildup of these chemicals on the skin can trigger eczema in some individuals, particularly in the sweatiest areas of the skin.

Hot temperatures can also worsen eczema symptoms by encouraging the dilation of blood vessels to help the body cool down, triggering inflammation and leading to itching.

Research has also found that people with atopic dermatitis (AD), the most common type of eczema, have a different composition of sweat than those without the condition.

Individuals with AD have significantly lower levels of certain substances in their sweat, meaning it contains less natural moisturizing and antimicrobial properties. This may mean an increase in drier skin after sweating and a higher likelihood of skin infections.

Studies have shown that people with AD also sweat less than those without AD. With less sweating, skin with AD retains heat, becomes dry, and is more prone to itching and infection.

There may be a link between AD and an allergic reaction to the Malassezia antigen, a yeast found on the skin. Sweating may aggravate symptoms of this allergy.

It is almost impossible to avoid sweating. However, there are many ways to minimize skin irritation and avoid worsening eczema. Below are some tips for managing eczema at times when sweating is likely.

Exercise

To help manage sweating due to exercise, a person can follow this advice:

  • If exercising indoors, choose an environment with good ventilation or air conditioning.
  • Moisturize the skin before exercising.
  • Shower straight after exercising, use clean towels, and moisturize straight after drying.
  • Avoid hot water, as this can dry the skin.
  • If exercising outdoors, aim for the early morning or evening when it is cooler.
  • Take frequent breaks when exercising to cool down.
  • Use a cool compress on the skin to decrease the itching and heat.
  • Avoid peak hours of sunshine, stay in areas of shade, and always wear sunscreen.
  • Stay hydrated by drinking plenty of water.
  • If taps are unavailable nearby, bring extra bottles of water to rinse off sweat, then pat dry with a clean towel.
  • Wear loose-fitting clothing consisting of breathable materials such as cotton.
  • Avoid spandex or wool, as these can irritate the skin.
  • If intense workouts are causing flare-ups, try gentler exercise activities, such as walking and pilates, until the skin calms down.

In hot weather

The NEA offers the following tips for controlling eczema in hot weather:

  • Carry a handheld fan to help cool the body down.
  • Have plenty of water to hand to stay hydrated and wash sweat off the body.
  • After rinsing the body with water, pat the skin dry and reapply moisturizer and sunscreen.
  • Swimming in the sea may be beneficial due to the combination of salt and UV light, but salt can be drying if it stays on the skin, so wash it off straight afterward.
  • Rinse off or shower after being in chlorinated water.
  • Avoid eczema triggers where possible, including removing any pollen from clothing or skin after being outdoors.
  • Take any medications as necessary, such as antihistamines.

Dietary

Eating a nutritious, balanced diet may play a part in managing eczema symptoms. People may want to reduce their intake of saturated fats and excess sugars and include a range of anti-inflammatory foods, such as:

  • turmeric
  • dark green vegetables
  • foods high in omega-3, such as oily fish, walnuts, and olive oil
  • berries
  • green tea
  • dark chocolate
  • nuts
  • ginger

People with eczema may know certain triggers that cause a flare-up. These may be different for each individual.

Along with sweat, other common triggers for eczema flare-ups can include:

  • fabrics, such as wool and synthetic fabrics
  • pet dander
  • cockroaches
  • insect bites and stings
  • pollen, dust mites, and mold
  • weather changes, such as temperature changes, humidity, and extreme heat or cold
  • perfumes and other scented products
  • stress and anxiety

There are many ways to treat eczema, including prescription medications. To manage their condition at home, a person can take the following steps:

  • using a thick emollient, such as an ointment, two to three times each day and after bathing to protect the skin from drying out
  • taking short, lukewarm showers or baths for 5 to 10 minutes
  • applying a topical steroid or anti-inflammatory cream onto affected areas during flare-ups

Several related conditions affect sweat production and may irritate the skin. They include the below.

Heat rash

Heat rash, also known as sweat rash, prickly heat, or miliaria, is a rash that develops due to the blockage and inflammation of the sweat glands. It can occur due to:

  • a hot and humid environment
  • underdeveloped sweat ducts in a newborn baby
  • intense physical activity or exercise
  • fever
  • synthetic clothing or nonporous dressings against the skin

Taking steps to cool the skin and reduce sweating and irritation can help treat heat rash. People with miliaria can also try to remain in cool environments and avoid humidity. In some cases, doctors can recommend topical steroids to decrease the itching.

Hyperhidrosis

Hyperhidrosis is a condition where people sweat excessively. They may sweat heavily in certain areas of the body, or the condition can affect the whole body. This sweating even occurs when they are not exerting themselves.

Hyperhidrosis can impair a person’s quality of life and cause emotional distress. People with the condition may notice:

  • sweat-soaked clothes
  • wet, soft skin, which may peel in some places
  • difficulty carrying out everyday activities due to excessive sweating
  • frequent skin infections

Treatment for hyperhidrosis may include high-strength antiperspirants, prescription medication, or botulinum toxin injections.

Sweat can dry the skin and contains substances that may trigger eczema flare-ups in some people.

To help manage sweating and eczema, individuals can rinse sweat or any irritating substances off the skin as soon as possible.

Exercising in cooler environments and staying in the shade during hot weather may help reduce sweating and irritation. After rinsing off sweat, people can apply a thick moisturizer and sunscreen.