Nickel allergy is one of the so-called contact allergies (also type IV or late allergies). Unlike immediate-type allergies (which include, for example, allergies to pollen, insect venom, and most food allergies), delayed-type reaction takes time to develop.
Nickel is a hard, silvery-white metal found in the earth's crust. Since its discovery in 1751, it has become indispensable in industrial production processes. It is inexpensive and easy to process thanks to its elasticity. To stop the rise in nickel allergies, the European Union adopted a directive on nickel in regulating its use.
What is a nickel allergy?
Nickel allergy is one of the so-called contact allergies (also type IV or late allergies). Unlike immediate-type allergies (which include, for example, allergy to pollen, insect venom, and most food allergies), delayed-type reaction takes time to develop.
After contact with the allergen, it can take 24 to 72 hours for the first symptoms to become noticeable. The reason for this "delay" is called helper T cells (technical term: T lymphocyte).
Helper T cells play an important role in the immune system and are produced in the lymph nodes and lower layers of the skin. They are important to prevent certain infections. They cling to foreign bodies and activate other cells of the immune system to destroy the foreign body.
They then form the so-called memory T cells. These are cells that register and realize which intruders are undesirable and thus react faster in case of contact.
In a contact allergy, the helper T cell resembles a supposedly harmless substance like nickel. When the skin comes into contact with the environmental substance once more, the helper T cells migrate to the upper layers of the skin and cause an inflammatory reaction. The delay occurs among other things because cells have to travel in this way.
Nickel allergy in children and adults
The nickel is the most common contact allergen worldwide. There are several studies that have used skin tests to examine how many people have developed sensitization to nickel.
A European-scale study estimates that 25.9% of those surveyed in Italy, 24% in Spain and 11.9% in Denmark have this sensitivity.
However, sensitization does not mean that all those who are positive actually have allergic symptoms. One thing is certain: sensitization is a prerequisite for the manifestation of an allergy.
Conversely, this means that: The more sensitized people are in a country, the more likely they are to develop a so-called contact allergy.
It has been found that women generally have a higher risk of developing a nickel allergy than men. This is partly due to the fact that contact with jewelry and piercings promotes nickel sensitization.
Nickel allergy symptoms and complaints
The word "eczema" comes from the Greek and literally means "boil." For most of those affected, the discomfort is limited to the area of the skin that had contact with the allergen (for example, the skin around the navel on a belt buckle containing nickel or a button on the pants).
Common contact points with nickel are: palms, fingers, navel, ears, or wrists. The typical signs of allergy to nickel are itching, burning or severe pain s, redness, swelling, papules, blisters that ooze on the site contact in case of chronic contact, also scales or skin thickening.
Common causes and triggers
Nickel is almost everywhere. Metal can be found in jewelry, watches, batteries, piercings, coins, sunglasses, joint replacements, irons, stationery, paper, tattoo colors, flower pots, door handles, braces, cigarette smoke, musical instruments, kitchen utensils, umbrellas, leather goods. Hypodermic needles, hairpins, curling irons, pots and cell phones.
While braces and knitting needles had an allergic effect, buttons on jeans, costume jewelery, and piercings have come to light. Nickel allergies occur, for example, with cleaning specialists or cashiers.
The EU Nickel Directive stipulates that nickel-containing products intended for immediate and prolonged contact with the skin must not release more than 0.5 μg of nickel per square centimeter per week.
For piercings, the release limit was limited to 0.2 µg / cm² per week. The European REACH chemical regulation states that the nickel content in toys cannot exceed 0.5 μg Ni / cm 2 / week.
In addition to industrially manufactured products, foods such as potatoes, cereals, and fruits also contain nickel because they absorb metal from the soil during the growth process.
An important component of the diagnostic procedure is the so-called medical history. The doctor asks the patient about habits, family history, and symptoms, and then derives possible causes.
Sometimes it can be difficult to tell a contact allergy from other types of eczema, such as atopic dermatitis. A skin test can help the diagnostic process.
If nickel is suspected as an allergy trigger, the anamnesis result is further assured with a skin test. The patch test is used for contact allergy.
A patch with test chambers sticks to the skin, usually on the back. The test chambers contain allergen preparations and, if necessary, other substances with a suspected allergy. Results take place after 48 and 72 hours.
Contact allergies can be caused by various substances. In addition to nickel, cobalt, chromate, preservatives, plant and synthetic fragrances, balm or dyes can cause allergic inflammatory processes of the skin.
To avoid the allergen, it is important to identify the substance causing the allergy as precisely as possible.
How to treat nickel allergy
Those suffering from nickel allergies should stay away as much as possible from everyday objects containing nickel and especially avoid prolonged contact with the skin. If contact cannot be completely avoided, protective measures, such as gloves or protective clothing, can help.
If nickel allergy eczema persists even with careful avoidance of allergens, cortisone-containing creams can relieve symptoms.
In rare cases, eczema in patients with a pronounced nickel allergy may increase with the intake of foods containing nickel. However, before those affected are on a rigorous, nickel-reduced diet, a doctor must first perform an oral nickel challenge test.
Since both thresholds and trigger foods vary from patient to patient, only together with a nutritionist can you determine which foods you can eat and which you should skip.
The possibilities of immunotherapy for nickel allergy are currently being investigated.
Environmental factors that influence skin aging and carcinogenesis fall into the following major categories: sun radiation (ultraviolet radiation, visible light, and infra-red radiation), air pollution, tobacco smoke, nutrition, some less well-studied factors, and cosmetic products. Hydracellum