Allergic contact dermatitis

Eczema is a skin condition in which the skin becomes red, flaky, itchy and blisters filled with fluid may form. Allergic contact dermatitis is a form of eczema that occurs when someone comes into contact with a substance to which they are allergic. It is not always clear what someone is allergic to. It must be determined which substance or product causes the eczema. This can be done by means of a patch test. Afterwards, the eczema-causing substance should be avoided as much as possible.

The forms of contact dermatitis

The skin condition eczema is a collective name in which the skin becomes red, flakes, itches and blisters filled with fluid can develop. There are different forms of eczema. Some types of eczema are present from birth, but it can also develop later as a result of contact with an irritating substance. If these substances trigger an allergic reaction, it is called contact allergic eczema. Contact dermatitis is caused by a substance that enters your skin from outside. A distinction is made between two types of contact dermatitis:

  1. Contact eczema (orthoergic)
  2. Allergic contact dermatitis

Contact eczema (orthoergic)

You get orthoergic contact dermatitis when you come into contact with an irritating substance such as soap or a cleaning product. Chronic exposure triggers an inflammatory response in the skin. If the skin comes into contact with substances to which an allergy has developed, it is called allergic contact dermatitis. These can be all kinds of substances, such as cosmetics, metals, chemical products or plant substances. These substances that trigger the allergy are called allergens. The body’s immune system is activated. Sometimes it happens that there is allergic contact dermatitis in combination with eczema due to irritation.

Allergic contact dermatitis

Allergic contact dermatitis occurs when you have developed an allergy to a certain substance. When you first come into contact with the allergen, nothing happens. But if you come into contact with this substance again, your immune system will develop an allergy. It can happen quickly, but it can sometimes take years for the allergy to develop. It is also possible that after using a certain cream for years, you suddenly become allergic to it. Once you are allergic, the contact allergy usually lasts for the rest of your life. Once allergic, coming into contact with a small amount of the allergen is enough to trigger an allergic reaction.

The products that trigger an allergy

The place where the skin has come into contact with the allergen is usually the place where the eczema develops. You sometimes see this on watches or where you have an earring. Some substances only trigger an allergy if used in combination with exposure to sunlight, for example a sunscreen. There are thousands of substances to which someone can be allergic. The most common substances are:

  • Base metals such as nickel which you often see in cheap jewelry
  • Learn
  • Cement
  • Fragrances such as in perfume or cosmetics
  • Preservatives
  • Rubber
  • Glue
  • Plants and flowers
  • Hair dye and perm fluid, also called hairdresser’s eczema

The diagnose

It is sometimes difficult to determine which substance you are allergic to. Sometimes it can be determined based on the place where the allergy originates. For example, a spot on your stomach exactly where your trouser button is. It is not always so clear because the eczema sometimes arises in other places. If there is a suspicion of a contact allergy, the diagnosis is made by means of a patch test. The substances are stuck to your back with a plaster for a period of two days and after three days. The number of stickers depends on the suspicions, but usually a number of standard substances are tested. If a test is positive, the substance you are allergic to has been discovered.


The most important thing is to avoid the substance you are allergic to as much as possible. That will not always be possible. You need to know where the allergens are located. Fortunately, there are leaflets available for various allergens so that you can find out what the substances are contained in. Pay attention to the composition of cosmetic products. Do not rely on the terms hypoallergenic , dermatologically tested or pH neutral . It says nothing about the precise ingredients the product contains. The eczema itself can be treated with a corticosteroid cream or ointment. In case of a severe form of eczema, prednisone is sometimes temporarily chosen.

read more

  • Eczema complaints caused by stress
  • The protective role of the skin
  • Dry skin: what can you do about it?
  • Dealing with itching with eczema
  • The anatomy of the skin