HealthInfo West Coast-Te Tai Poutini
Allergic contact dermatitis
Mate harehare pānga pāwera
Allergic contact dermatitis is when your skin comes into contact with something you are allergic to (called an allergen).
It is different to irritant contact dermatitis. Irritant contact dermatitis can affect anyone. But you will only get allergic contact dermatitis if you are allergic to certain things that touch your skin.
Allergic contact dermatitis happens due to an allergic reaction to a chemical or substance. Many things can cause this. The most common are nickel (in a lot of jewellery), rubber (latex), hair dyes and some plants (such as ivy). Chemicals in make-up, soap, skincare products and plasters can also cause it.
Symptoms of allergic contact dermatitis
If you have allergic contact dermatitis, you will develop an itchy rash after coming into contact with the allergen. For example, you may get a rash on your eyelids if you are allergic to a chemical in your make-up. Or you might get a rash under your watch strap if you are allergic to nickel.
The rash usually happens a few hours after the contact, not within a few minutes like with hives. Your skin can become red, sore and swollen. This will settle down after a few days as long as your skin is no longer in contact with the allergen.
Diagnosing allergic contact dermatitis
Your general practice team can usually diagnose allergic contact dermatitis by the appearance of your skin. They will ask you questions about your symptoms. These will include when your symptoms first appeared, what you were in contact with and what worsened the symptoms. With your help, your general practice team will try to identify the allergen.
Laboratory tests are not usually required. But if it is not obvious what the allergen is, you might be referred to see a dermatologist (skin doctor) for patch testing. You can read about patch testing on DermNet NZ.
If you think your make-up or skincare products are causing allergic contact dermatitis, you can test them at home with a simple test. Put the product on a small area of sensitive skin (such as the inside of your upper arm) twice a day for 5 to 10 days in a row. If you get a rash there, it is likely you have allergic contact dermatitis. This is called the open user test. It is a useful way to check your products so you can stop using anything that causes problems.
Treating allergic contact dermatitis
Treatment includes:
- Avoiding contact with whatever you are allergic to. This is the main treatment for allergic contact dermatitis.
- Using emollients (topical moisturisers) on any affected area. These moisturise your skin to help rehydrate it and provide a barrier that helps your skin heal.
- Applying topical steroids. These are anti-inflammatory creams that you put directly onto your skin. A mild steroid cream with 1% hydrocortisone, which you can buy from a pharmacy, may help it to settle down more quickly. Ask your pharmacist for advice on what cream is best for you. You may need to see your healthcare provider to get stronger steroid creams or in severe cases, steroid tablets.
HealthInfo recommends the following pages
- DermNet NZ – Allergic contact dermatitis
Information about allergic contact dermatitis including what causes it and how it is treated.
Written by HealthInfo clinical advisers. Last reviewed February 2025.
SourcesReview key: HICOD-326084
