A nickel allergy usually develops from repeated exposure to items containing nickel. It is difficult to find a metal product that does not contain nickel, particularly if the item is silver-colored. The chart below contains just a sampling of potential sources of nickel.

Jewelry is frequently a source of nickel allergies. Some jewelry is marketed as being “hypoallergenic,” but consumers should be wary of such advertising. For instance, nickel may not be present in the posts of earrings, but still be present in the earrings themselves.

Nickel is a common alloy metal. The chart below provides an example of when nickel may be added to a metal as well as the potential for reaction. Again, this is only a partial list, and it is up to the consumer to ask the right questions regarding nickel content of jewelry and other products.

Experts disagree on whether or not those with nickel allergies need to avoid foods that contain nickel. It is possible that some physicians will recommend a patient abstain from consuming dietary nickel for a period of time to see whether or not this improves symptoms.

Sources of dietary nickel include:

In addition, any high acid foods (e.g., tomato sauce) cooked in stainless steel pots can cause the nickel coating on such pots to seep into the food. This may lead to high enough nickel content in the cooked food to trigger nickel allergies in sensitive people.