What is it about ?
Allergy is an overreaction of the body’s immune system against harmless substances. During a first contact, the body finds itself in a sort of state of alert (it is “sensitized”), pushing it to overreact at the time of subsequent contacts. An allergic reaction goes hand in hand with a rash or wheezing, for example. In contact eczema, an abnormal skin reaction occurs after contact with a substance foreign to the body (allergen).
There are two types of contact eczema, the “immediate” form and the “delayed” form:
- In the immediate form, symptoms occur as soon as the skin comes in contact with the allergen, for example natural rubber (latex), cats or dogs (dander or hair), root vegetables and other vegetables.
- In the delayed form, symptoms occur when the skin has been in contact with the allergen repeatedly for several weeks or even months, for example nickel, rubber (by the chemicals it contains), glue and some perfumes. A person can thus wear a piece of jewelry for a while without having the slightest problem, and then develop an allergic reaction at some point.
The pathological mechanism of contact eczema is complex. In principle, the skin constitutes a very strong barrier of the body against the outside world. The skin contains special cells that absorb foreign substances and show them, so to speak, to the white blood cells, the body’s defenders. If these white blood cells identify the foreign substance as harmless, there is no reaction. On the other hand, if they recognize that the substance is foreign to the body, then contact eczema develops.
What is its frequency?
Contact eczema is a common skin condition. In the Netherlands, it is estimated to affect more than 1% of the population. Presumably, the numbers in our country are of the same order of magnitude. But we do not have precise figures.
How to recognize it?
The main symptom of contact eczema is a rash that is itchy. Eczema can be recognized by the red area of the site where the skin came into contact with the allergen. There are also often small bumps, blisters, scabs and / or peeling skin (scales, skin dandruff). The rash may be dry or oozing. In case of oozing skin eczema, the area of the eczema is wet. The area dries out after a while and a film or scab forms.
As the name suggests, with contact eczema, symptoms occur where the skin has come in contact with the allergen. These may be the following locations:
- face and neck (cosmetics, earrings, necklace, etc.),
- armpits (deodorants),
- wrists and hands (watch, bracelet, gloves, tools, etc.),
- chest and hips (bra clip, belt, etc.),
- buttocks (use of ointment or suppositories against hemorrhoids),
- legs and feet (leather, pigments, rubber boots, products against fungal infections and odorous feet, etc.)
How is the diagnosis made?
An explanation of the patient and the appearance of the skin is usually sufficient to make the diagnosis. Eczema lesions have a rather characteristic appearance. But in some cases, it is more difficult to make the diagnosis. Sometimes the doctor can determine the trigger with the help of specific questions.
In case of doubt, additional tests are necessary. An example of this kind of test is the patch test whereby a number of common allergens are applied to the skin by means of special patches. This procedure helps determine which substance the skin is having an eczema reaction to.
But it also happens that the allergen simply cannot be found. Fortunately, the treatment is the same in many cases, so it is not always necessary to know the cause. In this case, however, it is more difficult to take preventive measures to avoid contact with the allergen.
What can you do ?
The best thing to do is to avoid trigger allergens. But this is not always possible.
Be sure to take good care of your skin. Dry skin is more sensitive to stimulation. This is why it is indicated to use a moisturizer. Be careful because some creams also contain allergens (some perfumes, for example). So choose a moisturizer that is as neutral as possible, without the addition of dyes, preservatives or perfumes.
What can your doctor do?
After making the diagnosis, your doctor will usually prescribe a cortisone cream or ointment. Cortisone acts on the inflammatory reaction and allows the skin to heal. Do not use these creams for too long. Their prolonged use weakens normal skin, which can potentially lead to eczema again. You will usually also be prescribed a moisturizer to continue to care for your skin. In very exceptional cases cortisone in tablet form may be helpful. If all of these drugs do not produce enough results, other treatments may be considered in consultation with a dermatologist, such as taking drugs that act on the immune system.
Want to know more?
- Dry skin: regular care – mongeneraliste.be – SSMG – Scientific Society of General Medicine
- Contact eczema (image) – DermIS – Dermatology Information System
- Allergological assessment (patch tests or prick tests), here, Where to find on this page of Cliniques St Luc UCL
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