Eczema Causes and Triggers

What causes eczema?

We don’t know what exactly causes eczema (often called atopic dermatitis). The American Academy of Dermatology (AAD) describes atopic dermatitis as a complex skin disease caused by an interaction between a person’s environment and their genes. People with eczema tend to have an overactive immune system that responds to topical irritants or allergens by producing inflammation.

There are many risk factors for eczema. Some causes of eczema include stress or allergens. Having extremely dry skin, coming in contact with allergic substances in shampoo or cleansers, having certain food allergies, hay fever (also called rhinitis), living in cold mountainous areas or places that are cold and damp for at least part of the year, or living in places that are swampy and hot: all of these environmental risk factors can contribute to the severity, intensity and frequency of an eczema flare up if you are genetically predisposed to this skin disease.

Research also shows that some people with eczema have a mutation of the gene responsible for creating filaggrin. Filaggrin is a protein that helps our bodies maintain a healthy protective barrier on the outermost layer of our skin. Without enough filaggrin to build and maintain a strong skin barrier, moisture can escape and then allow bacteria, viruses and allergens to enter the body; this exposed or “leaky” skin barrier can then lead to extremely itchy skin, dry scaly patches of skin, blisters, skin infections, red spots or bumps and other symptoms.

Eczema triggers

Healthcare providers, including dermatologists, and people with eczema will refer to a “trigger” as something that causes or aggravates their eczema. When trying to identify potential triggers, keep in mind that an eczema flare up can appear some time after exposure to a topical irritant or allergen. This lag time can make some triggers challenging to detect.

Eczema affects everyone differently

One person’s triggers may not be the same as another’s. You might experience eczema symptoms at certain times of the year or on different areas of your body.

Eczema affects everyone differently. One person’s triggers may not be the same as another’s. You might experience eczema symptoms at certain times of the year or on different areas of your body.

Common triggers include:

  • Dry skin: when your skin gets too dry, it can easily become brittle, scaly, rough or tight, which can lead to an eczema flare up. Learn more about the importance of moisturizing skin with eczema-friendly ointments and creams to manage severe eczema flare ups.
  • Irritants: everyday household products and even natural substances can cause your skin to burn and itch, or become dry and red. These potential allergens can include products that you use on your body or in your home, including: hand and dish soap, laundry detergent, shampoo, bubble bath and body wash, perfume or other items with added fragrances, or surface cleansers and disinfectants. Even some natural liquids, like the juice from fresh fruit, vegetables or meats, can irritate your skin when you touch them. Read how one mom helped her son’s eczema by changing her laundry routine.
  • Stress: emotional stress can be an eczema trigger, but it’s not exactly known why. Some people’s eczema symptoms get worse when they’re feeling “stressed.” Others may become stressed, just knowing they have eczema, and this can make their itchy skin flare up. Learn more about how stress and eczema are related.

Understanding eczema triggers

When identifying potential triggers, keep in mind that an eczema flare can appear some time after exposure. This lag time can make some triggers challenging to detect. Eczema affects everyone differently, so one person’s triggers may not be the same as another’s.

Here are some everyday things that can trigger an eczema flare or make it worse.

Metals, including: chromium cobalt, chloride, copper, gold, nickel; eczema in response to a topical allergen is called “contact dermatitis.” Read how one NEA Ambassador found her eczema trigger and eliminated all nickel from her environment.

Environmental allergens can include: cigarette smoke, cockroaches, dust mites, pet dander, pollen, insect bites, bee stings; allergic reactions to these triggers come in many forms.

Climate factors can include the change in season, extreme heat, extreme cold, dry weather or humid weather. Altitude can also trigger an eczema flare up. Other factors can include prolonged exposure to hot water, chlorine, salt water, skin yeast and overgrown Staph bacteria.

The many list of chemicals that can trigger an eczema flare include: amidoamine, bacitracin, benzalkonium chloride, benzophenones, black rubber, cinnamates, cocamidopropyl betaine, colophony (tree resin), diazolidinyl urea, dibenzoylmethanes, hydantoin, epoxy resin, formaldehyde, fragrance glyceryl, thioglycolate, imidazolidinyl, urea, lanolin, methyl methacrylate, methylchloroisothiazolinone, methylisothiazolinone, methyldibromo glutaronitrile, myroxylon pereirae (balsam of Peru), neomycin sulphate, octocryle, paraben, para-aminobenzoic acid (PABA), paraphenylenediamine potassium dichromate, propylene glycol quaternium 15, salicylates, tixocortol pivalate, tosylamide and formadehyde resin.

Materials such as latex can trigger eczema outbreaks; non-organic materials such as polyester can trigger eczema; and organic materials that are rough in texture, such as wool, can irritate the affected areas of the skin as well. Eczema often appears in the flexural areas behind the knees or elbows, where skin creases lead to rubbing and irritation or increased quantities of sweat that dries out the skin. Symptoms of eczema are as varied as the potential environmental factors that can lead to irritation: everyone is affected by this skin disease differently. Regardless of vaccine status, Covid-19 (or the Coronavirus) is also a potential trigger for eczema, possibly due to the stress of recovering from the virus, or the body’s heightened immune system response to the virus.

While routinely prescribed by healthcare providers, topical steroids, including corticosteroids and steroid lotions can trigger complications and side effects for people with atopic dermatitis. It is also important to recognize that eczema symptoms can be mistaken for a different skin condition called psoriasis. Read here to better understand the differences between eczema and psoriasis. For more information about the seven different types of eczema including atopic dermatitis, contact dermatitis, dyshidrotic eczema, neurodermatitis, nummular eczema, seborrheic dermatitis and stasis dermatitis read our overview here.

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