Nickel allergy is one of the most common causes of allergic contact dermatitis an itchy rash that appears when your skin touches a usually harmless substance. A dermatologist also can do a simple skin patch test. The doctor puts tiny amounts of nickel and other allergens on patches, which are applied to your upper back. If your skin is cracked or blistered, you should take off any metal jewelry right away and see your doctor for treatment to prevent infection.
Generally 30% to 40% of patients with occupational nickel allergy develop hand eczema. Involvement of the hands in a nickel-sensitized patient should raise the possibility that nickel is acting as an occupational allergen. But nickel can be found in many everyday items from coins to zippers, from cellphones to eyeglass frames. Once you develop nickel allergy, however, you will always be sensitive to the metal and need to avoid contact. If you have nickel allergy, your body reacts to nickel and possibly to other metals, such as cobalt and palladium.