What is nickel allergy?
Nickel is a common metal that is found in many metallic items, either electroplated or as an alloy and is used to make many things, including:
- Costume jewelry (especially earrings, silver and white gold)
- Apparel (clothing fasteners like snaps, zippers, and buttons)
- Metal tools
- Bathroom fixtures
- Furniture parts
- Machinery parts
- Nickel plating for metal alloys
- Mobile phones
Allergic contact dermatitis (a form of delayed allergy) occurs when skin that has become sensitive (allergic) to a substance, comes into contact with that substance. Symptoms may take as long as 72 hours or more after exposure to appear, usually at the site of nickel contact. There are also rare cases of immediate allergy to nickel appearing as a contact urticaria or hive-like reaction at the site of contact with the nickel-containing item.
There is another type of contact dermatitis called irritant contact dermatitis, which happens when skin is repeatedly exposed to a mild irritant, such as from detergents or frequent wet work. Symptoms of this type of cumulative irritant contact dermatitis are usually gradual in onset or can be immediate with severe exposures. Irritant contact dermatitis may predispose an individual to develop allergic contact dermatitis, for instance, to nickel.
Nickel allergy is something that some of us acquire after we are born. It is a common allergy that affects millions (about 10 percent or more) of the population in the U.S., where the most common underlying event is ear piercing. It is much more common in women than men. This may be because women are more likely to wear jewelry or have piercings.
Symptoms and Causes
What usually causes the nickel allergy rash to appear?
Sweat leaches nickel from many types of metal, especially stainless steel. This “free” nickel is then absorbed by the skin where it causes a rash. Tissue fluids are even more likely to dissolve nickel in jewelry, so the open wound from ear piercing is often a cause.
What are the symptoms of nickel allergy?
The symptoms of nickel allergy can be mild, or severe enough to be disabling. They include red skin, itching or burning sensations, blisters, cracked skin and, in severe cases, swelling and spread beyond the site(s) of initial contacts. A severe form of nickel allergy called systemic nickel allergy syndrome can also cause headaches, fatigue, nausea, vomiting and diarrhea.
Diagnosis and Tests
How is nickel allergy diagnosed?
Your doctor will examine your skin and talk to you about your medical history and what metals and other substances have contacted your skin. If the doctor suspects you have a nickel allergy, the next step might be a patch test. Tiny amounts of substances that might cause an allergic reaction, including nickel, are placed on your back and covered with patches that remain in place for 2 days. The patched test sites are then analyzed after two days, and again two or more days after that.
Management and Treatment
How are the symptoms of nickel allergy treated?
There is no “cure” for nickel allergy, but avoidance of contact with the inciting object(s) often results in clearing of the rash. Treatments for contact allergies include lotions and creams, oatmeal baths, and other medications called topical corticosteroids that decrease inflammation. Antihistamines, medications that block a substance the immune system releases when it encounters something it is allergic to, can also be used. You might have to try different medications to see what works for you.
Systemic (usually oral or intramuscular) corticosteroids are occasionally used in short courses for severe spread of dermatitis. When other treatments have not helped, either because of spread of the contact allergy or association with other types of dermatitis such as atopic (endogenous) eczema (dermatitis), doctors sometimes use phototherapy – also called light therapy – which is the use of ultraviolet light on the skin. Phototherapy is a long process, and it can take months of steady treatments to produce an improvement.
How can nickel allergy be controlled?
If you are allergic to nickel, the best thing to do is to preferably avoid or decrease your exposure to nickel. Here are some ways to do that:
- Choose jewelry that does not contain nickel.
- Clothing fasteners like belt buckles and zippers are often made with nickel, but you can use plastic or plastic-coated ones instead.
- The same goes for household items like kitchen tools, keys, razors and eyeglass frames: choose things that do not contain nickel.
- Use a protective cover on electronic devices such as cell phones and laptop computers.
- Some foods contain small amounts of nickel, so in some cases where the rash involves the hands or areas beyond direct contact with nickel-containing objects, a low-nickel avoidance food trial may be prescribed. This involves not eating foods that contain a lot of it. These include soy products, nuts, chocolate, legumes (such as peas, beans, and lentils), and oatmeal.
- Wash any body part that you think might have come into contact with nickel.
- You can buy testing kits that use a compound called dimethylglyoxime to test objects for nickel.
Outlook / Prognosis
What is the outlook for people who are allergic to nickel?
Nickel allergy is not life-threatening. But because there is no cure, avoiding its symptoms can be a life-long challenge. It might affect your work, if your work brings you into frequent contact with nickel. This can be true for cashiers, locksmiths, carpenters and metalworkers, for example.
When should you call a doctor about nickel allergy?
If you have a rash and you do not know why, make an appointment to see a doctor. If you know you are allergic to nickel, and the treatments you are using are not working, see a doctor. Rashes can become infected. Symptoms that indicate an urgent need for medical help include:
- Rapidly spreading rash
- Increasing redness
- Rash around your eyes
- Pus in the area of the rash