Nickel allergy
[2] This often takes the form of a reddened patch of skin with raised bumps (papules) or small blisters (vesicles), and edema.[2] Particularly high levels of nickel exposure can cause irritated patches of skin to appear at other sites on the body (called "secondary eruptions").[8] Outbreaks of nickel allergy from consumer goods have been documented throughout the 20th century, with jewelry, stocking suspenders, and metallic buttons on blue jeans each resulting in dermatitis at the point of contact.Free (released) nickel that is able to penetrate the skin is taken up by scavenger (dendritic) cells and then presented to the immune system T-Cells.The metal cation Ni++ is a low molecular weight hapten that easily penetrates the stratum corneum (top layer of skin).[15] Upon re-exposure these now primed T cells will be activated and massively recruited to the skin, resulting in the elicitation phase and the clinical presentation of Ni-ACD.[16] [17] Nickel has a wide utility of application in manufactured metals because it is both strong and malleable, leading to ubiquitous presence and the potential for consumers to be in contact with it daily.The nanoparticles capture nickel ions by cation exchange, and remain on the surface of the skin, allowing them to be removed by simple washing with water.Approximately 11-fold fewer nanoparticles by mass are required to achieve the same efficacy as the chelating agent ethylenediamine tetraacetic acid.Using nanoparticles with diameters smaller than 500 nm in topical creams may be an effective way to limit the exposure to metal ions that can cause skin irritation'.Denmark in 1980, and then shortly after the European Union (EU), enacted legislation that limited the amount of free nickel in consumer products that come in contact with the skin.[ref 23][full citation needed] In the 17th century, copper miners in Saxony, Germany, began to experience irritation caused by a "dark red ore".[29] Josef Jadassohn described the first case of metal contact dermatitis in 1895, to a mercury-based therapeutic cream, and confirmed the cause by epi-cutaneous patch testing.[30] In the next century nickel began to be mass-produced for jewelry worldwide due to its cheap cost, resistance to corrosion and high supply.[34] The North American Contact Dermatitis Group (NACDG) patch tested 5,085 adults, presenting with eczema-like symptoms, showing 19.5% had a positive reaction to nickel.