What is allergic contact dermatitis?

Fact Checked

Allergic contact dermatitis is triggered by the bodily reaction to a substance that comes in contact with the skin. There are various substances that can cause allergic contact dermatitis which are commonly called as allergens. These substances will not cause any issues for most individuals. On the other hand, highly sensitive individuals will develop a rash. This rash does not appear until a day or two later but can start hours later or as late as a week.

Signs and symptoms

Allergic contact dermatitis can trigger symptoms such as swelling, redness and watery blisters that range in size from small to large. These blisters might break which forms crusts and scales. If not treated, the skin will blacken and become rubbery and fissured. This condition can be tough to distinguish from other types of rashes, particularly after it has been present for some time.

What are the common triggers?

Allergic contact dermatitis
Allergic contact dermatitis can trigger symptoms such as swelling, redness and watery blisters that range in size from small to large.

The doctor will discuss the materials that came in contact with the skin at home and work as well as attempt to identify the allergen. A patch test is performed which involves the application of a small amount of the suspected allergen to the skin for a fixed period, usually 2 days.


There are various chrome-plated objects that contain enough nickel to trigger a reaction among highly sensitive individuals. Take note that stainless steel also contains nickel but bound in a way which makes it safe for those sensitive to metal.

Earrings that contain nickel can instigate earlobe dermatitis. In most cases, the needles used to pierce the ears and the earrings can trigger this. Even clothing accessories such as zippers, buckles, metal clips and buttons that are made out of nickel can cause allergic contact dermatitis.

Rubber products

Latex often instigates allergic contact dermatitis. Exposure to certain products can cause burning, itching or hives. In some individuals, they experience itchy and teary eyes or even shortness of breath. This is quite common among those who wear rubber gloves, particularly in the healthcare field.

Paraphenylenedeamine (PPDA)

This is an ingredient usually found in permanent hair dyes which is combined with an oxidizing agent such as peroxide before application. Individuals who are allergic to PPDA should not use any permanent hair dyes.


These are compounds containing chromium which causes allergic contact dermatitis after contact with leather, cement, paint and anti-rust compounds. Exposure in the workplace is common especially in industries such as welding, automobile, cement, foundry, building repair and railroad.

Poison ivy

Poison ivy and related plants such as poison sumac and poison oak can trigger allergic contact dermatitis. In most cases, lines of small-sized blisters on the skin develop where the plant brushed against the skin.

What to do

Individuals with allergic contact dermatitis should find ways to avoid the potential allergen that triggers a reaction as well as materials that cross-react with it. Consulting a doctor is a must in order to help identify potential triggers to avoid. In addition, it is also recommended to substitute products made of materials that do not trigger any reactions.

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