Definition
Nickel allergy is one of the most common allergies that exist and belongs to the group of contact allergies (so-called contact dermatitis, allergic contact eczema). In this case, only direct contact with the allergenic substance (allergen), in this case nickel, leads to an inflammatory reaction, which is limited to the exact spot that came into contact with the substance. The symptoms of the nickel allergy, consisting of rash, itching and redness, usually disappear after a few days.
Nickel (Ni) is a white or silver shining, water-soluble chemical element, which belongs to the ferromagnetic heavy metals. It is part of many metal alloys, but is also contained in some foods. Nickel is important for humans because it is necessary for the function of certain enzymes. With the help of an allergy test, nickel allergy can be diagnosed and is usually easily controlled by avoiding objects containing nickel and treating the skin of the affected areas with special creams or ointments.
Symptoms of nickel allergy
Itching (urticaria) is a typical symptom of allergic reactions: The allergen, i.e. the substance causing the allergy, releases certain messenger substances in the body. An important representative of these substances is histamine, which in turn leads to the release of inflammation mediating substances. These in turn cause the blood vessels to dilate and become more permeable.
As a result, components of all kinds enter the surrounding tissue and cause itching at the corresponding site. Pustules, wheals or eczema are all typical skin reactions of a contact allergy, but strictly speaking they describe different skin symptoms. Pustules are small blisters on the skin that are filled with pus.
These can be caused by various inflammatory reactions and skin diseases, or even allergies. Pimples occur when fluid is deposited in the subcutaneous tissue, for example when the permeability of the blood vessels is increased by an allergic reaction. They then appear as flat, raised and reddened areas on the skin.
Eczema, on the other hand, is a collective term for various subspecies, of which allergic contact eczema is relevant here. This consists of the common occurrence of pustules, nodules and scales on the reddened and swollen area. Reddened and itchy skin is a typical symptom of a contact allergy as it can be caused by nickel.
The reason for the reddening of the skin is the dilation of the blood vessels, or medically “vascular dilatation”. This is mediated by certain messenger substances, which also ensure the appropriate body reaction in the case of inflammation. The purpose of this vasodilatation is actually to bring more blood to the corresponding part of the body and thus ensure that immune cells reach the tissue that is supposedly attacked by harmful foreign bodies.
As a result of the improved blood circulation, the reddened skin results. The painfulness and excessive sensitivity of skin areas affected by an allergic reaction is also due to the above-mentioned messenger substances that are released during such a reaction. In addition to vascular dilatation and increased vascular permeability, the pain receptors are also sensitized. The same mechanism intervenes in the body during an inflammation: pain, swelling and redness therefore fit both processes.
