Symptoms

A rash due to a nickel allergy will usually affect a small area of skin around the area of contact. It can be red and itchy.

Less commonly, nickel allergy causes a rash all over the body as a result of nickel being eaten and absorbed into the body. This has been reported to occur from orthodontic braces, tongue piercings, nickel leaching into food from old pots and pans, and even eating foods containing high amounts of nickel.

Causes

Nickel allergy may occur at any time during a person’s life, even when symptoms didn’t occur in the past. The tendency to react can run in families.

A person may have become allergic after being exposed to a large amount of nickel or after a nickel-containing material came into contact with broken skin (such as a cut or sunburn).

Foods that contain high amounts of nickel include legumes, leafy green vegetables, and various nuts and seafood, but only cause problems in highly sensitive people with a systemic nickel allergy. Most people with nickel allergy only have a reaction when their skin is exposed to nickel and do not need to worry about ingestion of small amounts of nickel that are naturally contained in many foods.

Diagnosis

Nickel allergy is diagnosed with the use of patch testing, which involves placing patches containing nickel and other chemicals onto the skin for 48 hours. The patches are then removed and the skin is marked.

Approximately 72-96 hours after the initial test placement, the final reading is usually performed. In people with nickel allergy, an itchy, red and/or blistering bump will have formed at the site of the patch test that they reacted to. A person with nickel allergy will often have reactions to other metals as well, such as cobalt and chromium.

Depending on history, a fourth visit may be scheduled to monitor for delayed skin reactions that are more common with some allergens than others.

Treatment

Treatment of nickel allergy mainly involves avoiding nickel-containing materials. A test to determine the presence of nickel in jewelry and other metallic devices, called a dimethylglyoxime test, is available commercially.

When a rash occurs as a result of exposure, topical steroid creams can be helpful to treat the symptoms.