When your body comes into contact with something that could make you sick, your immune system promotes chemical changes to help your body ward off disease.
You’re exposed to thousands of substances each day, and most don’t cause your immune system to react. In some cases, however, you may come into contact with certain substances that trigger an immune system response, even if they aren’t typically harmful to the body. These substances are known as allergens. When your body reacts to them, it causes an allergic reaction.
An allergic reaction can take a number of forms. Some people experience difficulty breathing, coughing, burning eyes, and a runny nose when they’re having an allergic reaction. Other allergic reactions cause changes in the skin.
Allergic eczema is an itchy skin rash that develops when you come into contact with an allergen. The condition often occurs hours after you’ve been exposed to the substance that triggered the allergic reaction.
Allergic eczema is also known as:
- allergic dermatitis
- contact dermatitis
- allergic contact dermatitis
- contact eczema
Allergic eczema occurs when you come into direct contact with an allergen. The condition is known as a “delayed allergy” because it doesn’t trigger an allergic reaction right away. The symptoms of allergic eczema may not develop for 24 to 48 hours after you’ve come into contact with the allergen.
Some common triggers for allergic eczema include:
- nickel, which can be found in jewelry, belt buckles, and metal buttons on jeans
- perfumes found in cosmetics
- clothing dyes
- hair dye
- soaps and cleaning products
- poison ivy and other plants
- antibiotic creams or ointments that are used on the skin, such as neomycin
Allergic eczema may also develop when the skin is exposed to chemicals in the presence of sunlight. For example, an allergic reaction can occur after using sunscreen and spending time in the sun.
The symptoms of allergic eczema can vary from person to person. They may also change over time. Symptoms typically develop where contact with the allergen has occurred. In rare cases, symptoms might spread to other areas of the body.
Common symptoms include:
- a burning sensation or pain
- red bumps that may ooze, drain, or crust
- warm, tender skin
- scaly, raw, or thickened skin
- dry, red, or rough skin
Your doctor will first examine your skin to determine whether you have allergic eczema. If they suspect you have the condition, they’ll need to do further testing to find out exactly what you’re allergic to. In most cases, an epicutaneous or patch test will be used.
During this test, patches that contain common allergens are placed on your back. These patches remain in place for 48 hours. When your doctor removes the patches, they’ll check for symptoms of an allergic reaction. Your doctor will check your skin again after two more days to see if you have a delayed allergic reaction.
Other tests will be needed if your doctor isn’t able to make a diagnosis based on the patch test. Your doctor may perform a skin lesion biopsy to make sure another health condition isn’t causing your skin condition. During the biopsy, your doctor will remove a small sample of the affected skin and send it to a laboratory for testing.
Treatment for allergic eczema depends on the severity of your symptoms. In all cases, however, it’s important to wash the affected skin with plenty of water to remove traces of the allergen.
You may not need additional treatment if your symptoms are mild and don’t bother you. However, you might want to use a moisturizing cream to keep the skin hydrated and repair damage. Over-the-counter corticosteroid creams can help with itching and inflammation.
Your doctor may recommend prescription-strength ointments or creams if your symptoms are severe. They may also prescribe corticosteroid pills if needed.
With the proper treatment, you can expect allergic eczema to clear up within two to three weeks. However, the condition may return if you’re exposed to the allergen again. Identifying the allergen that caused your eczema and taking steps to avoid it are critical to preventing future reactions.