Contact dermatitis facts for kids

Quick facts for kids Contact dermatitis
A rash from contact dermatitis.

Contact dermatitis is a type of skin inflammation that happens when your skin touches something that irritates it or causes an allergic reaction. It can make your skin itchy, dry, red, or bumpy. Sometimes, it can even cause blisters or swelling.

This type of rash is not contagious, which means you can't catch it from another person. While it's not dangerous, it can be very uncomfortable. The rash usually appears only on the part of the skin that touched the substance.

There are two main types of contact dermatitis. The most common is irritant contact dermatitis, which happens when the skin is damaged by a harsh substance. The other type is allergic contact dermatitis, which is when your body's immune system reacts to a substance.

What Does It Look and Feel Like?

Contact dermatitis is a rash that shows up after you touch a certain substance. It's different from hives, which appear very quickly and also fade quickly. A contact dermatitis rash can take a few days or even weeks to go away, and it will only heal if you stop touching the substance that caused it.

The symptoms for both irritant and allergic dermatitis can include:

• A red rash: This is the most common sign. With irritant dermatitis, the rash appears right away. With allergic dermatitis, it might take 1 to 3 days to show up.
• Bumps or blisters: Small bumps or fluid-filled blisters can form on the skin where it touched the substance.
• Itchy or burning skin: Allergic dermatitis is often very itchy. Irritant dermatitis tends to be more painful or cause a burning feeling.
• Dry or cracked skin: The skin might become dry, scaly, or cracked, especially if you keep touching the irritant.

Irritant dermatitis usually stays in the exact spot that touched the substance. Allergic dermatitis can sometimes spread to a wider area.

What Causes This Type of Rash?

Many different things can cause contact dermatitis. Some are found at home, while others might be in the workplace or outdoors. There are three main types based on what causes the reaction.

Irritant Contact Dermatitis

Contact dermatitis caused by handling damp wood without gloves.

This is the most common type, making up about 80% of all cases. It happens when a substance directly damages the outer layer of your skin. It's not an allergic reaction. Anyone can get it if they are exposed to a strong enough irritant for a long enough time.

Common irritants include:

• Harsh soaps, detergents, and cleaning products
• Acids and alkalis, like drain cleaners
• Solvents like alcohol or paint thinner
• Too much exposure to water, like from washing your hands very often
• Low humidity, such as from air conditioning, which can dry out the skin
• Some plants

Allergic Contact Dermatitis

A three-year-old girl with a rash one day after touching poison ivy.

This type of rash is an allergic reaction. Your immune system overreacts to a substance that is normally harmless. You might not get a rash the first time you touch an allergen. But during that first contact, your body becomes "sensitized." The next time you touch it, your immune system is ready to react, causing a rash.

Common allergens include:

• Nickel: A metal often found in jewelry, buckles, and buttons.
• Poison ivy, poison oak, and poison sumac: Plants that have an oily coating called urushiol.
• Fragrances and perfumes: Found in cosmetics, soaps, and lotions.
• Latex: Found in things like rubber gloves and balloons.
• Some chemicals used in hair dyes or clothing.

Photocontact Dermatitis

This is a less common type of rash. It happens when a substance on your skin only causes a reaction after it's exposed to sunlight. The ultraviolet (UV) light from the sun "activates" the substance, leading to a rash on the parts of your body that were in the sun, like your face, neck, and arms.

Substances that can cause this include some sunscreens, perfumes, and even certain plant saps.

How Do Doctors Find the Cause?

A patch test helps find out what someone is allergic to.

To figure out what is causing your rash, it's important to identify the irritant or allergen. A doctor can often tell what it is by looking at the rash and asking you questions about what you've touched.

If a doctor suspects you have allergic contact dermatitis, they may recommend a patch test. During this test, a doctor will put tiny amounts of common allergens on small patches and stick them to your skin, usually on your back. You wear the patches for about two days. When the patches are removed, the doctor checks your skin for any reaction. A small red bump under a patch means you are likely allergic to that substance.

Knowing what caused the reaction is the key to avoiding it in the future.

How to Prevent Contact Dermatitis

The best way to prevent contact dermatitis is to avoid the substances that trigger it. Here are some tips:

• Identify and avoid your triggers. Once you and your doctor know what causes your rash, do your best to stay away from it.
• Wear protective clothing. If you have to handle an irritant or allergen, wear gloves, long sleeves, or other protection.
• Wash your skin. If you accidentally touch a known trigger, like poison ivy, wash the area with soap and cool water as soon as possible.
• Use barrier creams. Special creams can provide a protective layer on your skin to block irritants.

How to Treat the Rash

At-Home Care

For mild cases, you can often treat the rash at home.

• Avoid scratching. Scratching can make the rash worse and could lead to an infection.
• Use cool compresses. Placing a cool, wet cloth on the rash for 15-30 minutes several times a day can help reduce itching and swelling.
• Apply soothing lotions. Calamine lotion or a non-prescription hydrocortisone cream can help relieve itching.
• Take oral antihistamines. Over-the-counter allergy pills like diphenhydramine (Benadryl) can help reduce itching, especially at night.

When to See a Doctor

You should see a doctor if:

• The rash is not getting better after a few days of home treatment.
• The rash is spreading or covers a large area of your body.
• The itching or pain is severe and keeps you from sleeping or focusing.
• The rash is on your face or affects your eyes.

A doctor can prescribe stronger treatments, such as corticosteroid creams, pills, or injections, to reduce the inflammation and help your skin heal.

See also

• Eczema
• Hock burns
• Nickel allergy
• Urushiol-induced contact dermatitis