When do the symptoms appear?
Nickel allergy is a late-type allergic reaction, which means that the rash does not appear immediately upon first contact. The skin changes are mediated by the cells of the immune system and usually appear on the skin one to three days after the first contact.
Where do the symptoms appear?
In general, a rash as a reaction to a nickel allergy can occur wherever the skin comes into contact with the nickel. Nickel is often used in cheap costume jewelry or watches, so neck and wrists or earlobes are the most common places where the rash occurs as a result of a nickel allergy. But also belt buckles often contain nickel, the rash forms near the navel. Some spectacle frames, zippers and shoe buckles also contain nickel.
Nickel allergy through food
In some foods, nickel is present in not inconsiderable amounts, of which about 10% is absorbed into the bloodstream. Especially a lot of nickel is found in: For some people, even very low concentrations of nickel are sufficient to cause a nickel allergy, for others the threshold is much higher.
- Pulses
- Cocoa
- Strawberries
- Black tea
- Coffee
- Soya
- Mussels
- Nuts and
- Foods that are stored in canned foods, because the nickel from the canned food can pass into them.
The exact cause of a nickel allergy is not yet known.
It is partly hereditary, so people with a corresponding hereditary predisposition are more likely to develop hypersensitivity than those who do not. However, the nickel allergy is an allergy that can develop gradually, so it can only develop if there has been frequent contact with nickel-containing substances over many years. For this reason, many more women suffer from nickel allergy than men, as they wear more and more jewelry.
Items that very often contain nickel and can therefore be the cause of an allergic reaction are jewelry (especially earrings and piercings), watches, belts, eyeglasses frames, dentures, buttons, zippers, hair care products and detergents, coins or cutlery. The nickel allergy is an allergy type IV or also known as late type or delayed type, which is due to the fact that the symptoms only appear about 12 hours after exposure. This type of allergy is a special type of hypersensitivity reaction in that it does not involve antibodies.
Here, special white blood cells, the so-called T-cells, are responsible for the allergic reaction of the body. What happens is that the defence system (immune system) of those affected mistakenly sees nickel as a dangerous intruder that it tries to fight. After initial contact with the substance nickel, “sensitization” occurs, which means that some T cells become specialized in recognizing the nickel antigen.
This phase of sensitization lasts between 8 and 21 days and results in so-called memory cells, which are so named because they can practically “remember” contact with nickel. It is only when there is a second contact with nickel that the body actually shows a reaction to the substance. This happens because the memory cells transform into effector cells that cause inflammatory cells to migrate. These then release substances such as histamine, which then lead to the typical signs of inflammation such as redness, water retention or itching.
