Found this in the news .
NEW YORK (Reuters Health) - Smoking may increase the risk of
developing allergies to a wide variety of materials, including metal
found in earrings and in the buttons of blue jeans, a group of Danish
researchers has found.
So-called contact allergies are reactions – such as red itchy skin
– that occur in response to touching a particular substance.
Dr. Allan Linneberg at Glostrup University Hospital in Copenhagen
found that contact allergies to nickel – which is found in earrings
and in the buttons to blue jeans – were more common among smokers.
Although allergies to nickel sometimes develop in people who wear
earrings, smokers had an increased risk of nickel allergy whether or
not they wore earrings.