Although eczema rashes can be intensely itchy, scratching may cause them to get bigger or spread.

Eczema is an umbrella term for a group of inflammatory skin conditions characterized by patches of sore, itchy, or flaky skin. Eczema can occur almost anywhere on the body. Rashes may appear in one particular area of the body, or they may affect multiple body parts.

This article describes what eczema is, how it develops, and the factors that can cause it to flare up. It also provides tips on how to prevent eczema from spreading.

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Eczema refers to a group of inflammatory skin conditions that cause the skin to become sore, itchy, or flaky.

According to the National Eczema Association, eczema is a common condition, affecting over 31 million people in the United States. The condition can develop in childhood, adolescence, or adulthood.

The factors that cause or worsen eczema depend on the type of eczema a person has. Atopic dermatitis, the most prevalent form of eczema, is more likely in people with:

  • a family history of eczema, asthma, or allergies
  • a lack of the protein filaggrin, which helps to protect the outermost layer of the skin
  • exposure to environmental triggers, such as smoke or pollution

Other environmental factors that can trigger eczema flare-ups include:

  • stress
  • wearing rough fibers, such as wool or polyester
  • exposure to dry, cold air
  • exposure to fragrances, dyes, or other additives in skin care products
  • contact with chemicals that irritate the skin
  • exposure to potential allergens, such as dust, pollen, and animal dander
  • foods that people are allergic or sensitive to

A person may have eczema that is localized to one part of the body. Alternatively, it may spread over a larger area or develop in multiple locations.

In infants, eczema typically occurs on the following parts of the body:

  • cheeks
  • forehead
  • scalp
  • neck
  • legs

In children and adults, eczema is most common on the:

  • face
  • neck
  • upper chest
  • wrists
  • hands
  • fingers
  • backs of the knees
  • elbow creases
  • ankles
  • feet

There are several reasons eczema may spread. These include:

Itching

Itchiness is a prominent eczema symptom, but scratching can trigger the release of inflammatory substances that create more inflammation. This causes rashes to get bigger or spread. Doctors refer to this as the itch-scratch cycle.

Allergens and irritants

People with contact dermatitis get eczema rashes due to direct contact with an allergen or irritant on their skin. These substances or materials can trigger inflammation. For example, if a person is allergic to their laundry detergent, they may get a rash in various places on their body.

Bacteria

Sometimes, cracked and dry skin can become colonized by harmful types of bacteria. These can cause further inflammation and infect the broken skin.

If a person scratches an area of infected skin and then an area that is dry or chapped, the bacteria may spread to the dry or chapped area. An infection can also spread on its own unless a person seeks treatment.

Preventing the spread of eczema depends on the type of eczema a person has. For example, contact dermatitis will stop spreading once a person removes the source of irritation. Eczema that has become infected may require topical or oral antibiotic treatment.

One of the main ways people can prevent eczema from becoming more inflamed and itchy is to avoid scratching. Treating flare-ups as quickly as possible can remove the temptation to scratch. It may also help if people keep fingernails trimmed or wear cotton gloves to bed.

Treating flare-ups

Treating flare-ups quickly often involves a topical treatment that people can get from a doctor or dermatologist. These include corticosteroid creams to reduce inflammation and emollients that form a protective barrier over the skin to help lock in moisture.

Some people may benefit from antihistamines to help relieve itching. If the itching is severe, immunosuppressant tablets can help suppress the immune system from launching an inflammatory response.

To ease symptoms during a flare-up, people can also:

  • Bathe or shower in lukewarm water.
  • Apply cold compresses.
  • Apply moisturizer liberally and frequently throughout the day, especially after getting the skin wet.

Preventing future flare-ups

Preventing future flare-ups will depend on the trigger of a person’s eczema. If the trigger is unclear, a person may benefit from keeping a symptom diary to see commonalities between episodes.

Other things people can do include:

  • managing stress
  • getting tested for allergies and avoiding allergens
  • removing common irritants from the household
  • using gentle skin products with a low pH
  • keeping the home at a comfortable temperature
  • wearing loose-fitting clothes in soft, breathable fabrics
  • regularly washing fabrics in frequent contact with the skin
  • wearing gloves while washing up or cleaning

A person should contact a doctor about their eczema if they experience any of the following:

  • eczema so severe it affects their daily life
  • lesions covering large portions of their body
  • lesions that appear infected and are producing pus
  • difficulty treating their eczema with over-the-counter products

Eczema is a common inflammatory skin condition that causes patches of sore, itchy, or flaky skin. It can spread for several reasons, depending on the type of eczema a person has.

A dermatologist can help with identifying eczema types and triggers. Treating flare-ups as soon as they occur can help break the itch-scratch cycle and keep eczema from spreading.