What is nickel allergy

Nickel allergy is one of the most common causes of contact allergic dermatitis. In affected individuals, dermatitis (also called eczema) develops in places where nickel-containing metal is touching your skin.

The most common sites for nickel dermatitis are the earlobes (from earrings), the wrists (from a watch strap) and the lower abdomen (from a jeans stud), but nickel can be found in many everyday items, such as coins, zippers, cellphones and eyeglass frames. The affected areas become intensely itchy and may become red and blistered (acute dermatitis) or dry, thickened and pigmented (chronic dermatitis).

Contact allergic dermatitis to nickel may develop at any age and in males and females. Once this nickel allergy has developed, it persists for many years, often life-long.

Nickel allergy is more common in women, probably because they are more likely to have piercings than men, although this is changing. The degree of nickel allergy varies. Some people develop dermatitis from even brief contact with nickel-containing items, while others break out only after many years of skin contact with nickel.

Can nickel allergy affect areas that are not in contact with metal?

This has been debated by dermatologists.

Some people develop intermittent or persistent eczema on their hands and feet. Nickel allergy is usually a blistering type of eczema, known as pompholyx or dyshidrotic hand dermatitis. Sometimes it is due to contact with metal items containing nickel, but often there is no obvious reason for it.

It has been suggested that in nickel allergic people pompholyx may be due to nickel in the diet. Unfortunately it is not possible to avoid ingesting nickel as it is present in most foodstuffs. A low-nickel diet is only rarely helpful.

Figure 1. Nickel allergy rash

Figure 2. Nickel allergy earrings

Nickel allergy causes

The exact cause of nickel allergy is unknown. As with other allergies, nickel allergy develops when your immune system views nickel as a harmful, rather than harmless substance. Normally, your immune system only reacts to protect your body against bacteria, viruses or toxic substances.

Once your body has developed a reaction to a particular agent (allergen) — in this case, nickel — your immune system will always be sensitive to it. That means anytime you come into contact with nickel, your immune system will respond and produce an allergic response.

Your immune system’s sensitivity to nickel may develop after your first exposure or after repeated or prolonged exposure. Sensitivity to nickel may, in part, be inherited.

Sources of nickel exposure

Common items that may expose you to nickel include:

• Jewelry for body piercings
• Other jewelry, including rings, bracelets, necklaces and jewelry clasps
• Watchbands
• Clothing fasteners, such as zippers, snaps and bra hooks
• Belt buckles
• Eyeglass frames
• Coins
• Metal tools
• Cellphones
• Keys
• Military “dog-tag” ID
• Chalk
• Medical devices
• Laptops or computer tablets
• E-cigarettes

Risk factors for nickel allergy

Certain factors may increase your risk of developing a nickel allergy, including:

• Having ear or body piercings. Because nickel is common in jewelry, nickel allergy is most often associated with earrings and other body-piercing jewelry containing nickel.
• Working with metal. If you work in an occupation that constantly exposes you to nickel, your risk of developing an allergy may be higher than it is for someone who doesn’t work with the metal. In addition, people who have regular exposure to nickel while doing “wet work” — as a result of either sweat or frequent contact with water — may be more likely to develop nickel allergy. These people may include bartenders, people who work in certain food industries and domestic cleaners. Other people who may have an increased risk of nickel allergy include metalworkers, tailors and hairdressers.
• Being female. Females are more likely to have a nickel allergy than are males. This may be because females tend to have more piercings. A recent study found that overweight women seem to have an even higher risk of nickel allergy.
• Having a family history of nickel allergy. You may have inherited a tendency to develop a nickel allergy if other people in your family are sensitive to nickel.
• Being allergic to other metals. People who have a sensitivity to other metals may also be allergic to nickel.

Nickel allergy prevention

The best strategy to prevent a nickel allergy from developing is to avoid prolonged exposure to items containing nickel. If you already have a nickel allergy, the best way to prevent an allergic reaction is to avoid contact with the metal.

However, it’s not always easy to avoid nickel because it’s present in so many products. Home test kits are available to check for nickel in metal items.

The following tips may help you avoid nickel exposure:

Test your metal items for nickel

Test your metal items to see if they contain nickel. Obtain a nickel-testing kit from your dermatologist, pharmacist or online supplier. The kit consists of two small bottles of clear fluid; one contains dimethylglyoxime and the other ammonium hydroxide. When mixed together in the presence of nickel, a pink color results. The dimethylglyoxime nickel spot test is highly specific but only moderately sensitive to nickel ¹.

Apply a drop from each bottle on to the metal item to be tested – first try it on a coin. Use a cotton bud to rub gently – observe the color on the bud. If it remains clear, the item has no free nickel and will not cause dermatitis. If it is pink it contains nickel and may cause dermatitis if the metal touches your skin. The chemicals will not harm your jewellery.

Jewellery

Necklaces, necklace-clips, earrings, bracelets, watch-straps and rings may contain nickel. “Hypoallergenic” stainless steel, solid gold (12 carat or more) and silver jewellery should be safe. Nine-carat gold and white gold contain nickel. Plastic covers for earring studs can be obtained. Coating the stud with nail varnish is not recommended as the varnish soon chips off.

Nickel in clothing

Metal zips, bra hooks, suspender clips, hair-pins, buttons, studs, spectacle frames etc. are likely to contain nickel. Use substitutes made of plastic, coated or painted metal or some other material.

Nickel in personal articles

Personal items with nickel that may touch the skin causing dermatitis include mobile phones, lipstick holders, powder compacts, handbag catches, cigarette lighters, razors, keys, key rings, knives, and pens. These may sometimes cause dermatitis when they are within a pocket.

Metal items in the home

Cupboard handles, kitchen utensils, cutlery, toaster, metal teapots, scissors, needles, pins, thimble, vacuum cleaners, torches, bath plugs and many other items may contain nickel. Choose tools with plastic handles.

Stainless steel does not usually cause dermatitis unless it is nickel-plated.

Money

Silver-colored coins are composed of cupro-nickel. Cashiers with nickel allergy may develop hand dermatitis from this source. Wear gloves to handle money or pay with a credit card or check.

Metal at work

Nickel dermatitis may be aggravated by contact with paper clips, typewriter keys, instruments, metal fragments from a lathe or chain saw.

Wear hypoallergenic jewelry

Avoid jewelry that contains nickel. Purchase jewelry that’s made of materials that aren’t likely to cause allergic reactions. Look for jewelry made from such metals as nickel-free stainless steel, surgical-grade stainless steel, titanium, 18-karat yellow gold, or nickel-free yellow gold and sterling silver.

Surgical-grade stainless steel may contain some nickel, but it’s generally considered hypoallergenic for most people. Be sure that your earring backings also are made of hypoallergenic materials.

Choose a piercing studio carefully

Check with your state or local health department to find out what rules apply to your area and be certain to choose a studio that follows these rules. Visit a studio before getting a piercing to make sure that the piercer provides a clean, professional environment.

Also, check to be sure the studio uses sterile, nickel-free or surgical-grade stainless steel needles in sealed packages. If the studio uses a piercing gun, check to see if the part that touches the person getting pierced isn’t used on other customers. Check that the studio only sells hypoallergenic jewelry and can provide documentation of metal content of the products for sale.

Use substitute materials

Look for safer substitutes for common nickel-containing items:

• Watchbands made of leather, cloth or plastic
• Zippers or clothing fasteners made of plastic or coated metals
• Plastic or titanium eyeglass frames

Create a barrier

If you have to be exposed to nickel at work, creating a barrier between you and the nickel may help. If your hands have to touch nickel, wearing gloves may help.

Try covering buttons, snaps, zippers or tool handles with duct tape or with a clear barrier, such as Nickel Guard. Clear nail polish on jewelry may help, but may have to be reapplied often.

Nickel allergy food

Nickel is contained in a variety of foods and has been implicated in certain allergic skin conditions.

It is possible that the kind of dermatitis you have will improve if you follow a die that is low in nickel. Although nickel cannot be completely removed from the food you eat, it is possible to reduce nickel intake by half by avoiding foods with a high nickel content. The dermatitis will probably not clear completely during the diet period, but you are likely to see fewer and shorter flares.

To determine whether you can benefit from diet treatment, the diet instruction must be followed carefully for 1 to 3 months. It is important not to begin the diet at a time when you anticipate travel abroad or plan to participate in many social activities.

If your dermatitis clears or improves considerably after 1 to 3 months of following the diet, you can adjust the instructions as follows:

• Follow the diet strictly when eating at home, and adapt it to suit the circumstances when eating out.
• It is important to continue at all times to avoid those foods that have a very high nickel content. These include bran, oats, buckwheat, soy, legumes (in particular dried legumes, such as dried peas and beans), chocolate, cocoa, all kinds of nuts (including peanuts), and licorice.
• If you decide to break the diet with any of these foods, eat them in very small amounts.
• If you find it difficult to satisfy your appetite, it is best to supplement meals with foods containing very little nickel, for example, milk products, meat, potatoes, and cooked carrots.
• If after following the diet for 1 to 3 months you see no improvement in your dermatitis, the diet should be discontinued.

The following food items have a high nickel content ²

Grains and grain products:

• Bran
• Buckwheat
• Millet
• Muesli and other similar breakfast cereals
• Multi grain breads
• Oatmeal
• Rice (unpolished)
• Rye bran
• Sesame seeds
• Sunflower seeds
• Wheat bran and other bran and fiber products, including cereals, bran biscuits, fiber tablets

Fruit, berries

• Dates
• Figs
• Pineapple
• Prunes
• Raspberries

Meat, fish, poultry

• Shellfish like shrimp, mussels and crawfish

Dairy products

• Chocolate milk

Vegetables

• Beans (green, brown, white)
• Kale
• Leeks
• Lettuce
• Lentils
• Peas (green and split)
• Soy protein powder (used in sausages, sandwich meat, products made from minced meat, bread soup concentrates, bouillon)
• Spinach
• Sprouts made from beans and alfalfa

Drinks

• Chocolate and cocoa drinks
• Tea from drink dispensers

Miscellaneous

• Almonds
• Baking powder (in large amounts)
• Hazelnuts and other nuts
• Peanuts
• Sweets containing chocolate, marzipan, nuts, strong licorice
• Vitamins containing nickel

Various food items and drinks can aggravate nickel dermatitis even though the nickel content of these foods may be low. These include beer, wine (in particular, red wine), herring, mackerel, tuna, tomato, onion, carrot, and certain fruits, in particular, apples and citrus fruits (juice). These vegetables can usually be tolerated when cooked.

The first liter of water taken from the tap in the morning should not be used in food preparation, as nickel may be released from the tap during the night. Nickel-plated kitchen utensils, such as egg beaters and tea balls, should be replaced.

Acid foods such as stewed fruits and rhubarb cooked in stainless steel utensils should be avoided. The acids in the foods can cause nickel to be released from the utensils. Canned foods should be eaten only in moderation.

Hand dermatitis that is affected by nickel in food will also be made worse by other conditions. Prolonged physical contact with nickel-plated items should be avoided. Other substances that can irritate sensitive skin, such as soapy water, household cleaning agents, raw fruits and vegetables, garden soil, and oil products used in repair work, should also be avoided.

Systemic nickel allergy syndrome

Systemic nickel allergy syndrome is characterized by contact dermatitis associated with systemic symptoms after ingestion of foods containing nickel ³. This definition has been recently coined to describe a clinical condition that links together cutaneous manifestations (such as allergic contact dermatitis, pompholyx, erythema, urticaria, angioedema, and dysydrosis), gastrointestinal disorders with mucosa histopathologic changes and a number of systemic clinical manifestations, including, but not limited to, headache, chronic fatigue, cystitis and/or vulvovaginitis, and iron-deficiency anemia, all related to the intake of nickel-containing foods ⁴, ⁵, ⁶.

Da Mata and colleagues ³ conducted a nickel elimination diet on 331 adult patients (aged between 18 and 65 years) who’ve had positive skin patch test for nickel and who had symptoms suggestive of systemic nickel allergy syndrome. During the elimination diet of rich food in nickel for 60 days, patients reported significant improvement and/or absence of symptoms, mainly gastrointestinal and cutaneous. After the period, the nickel diet was reintroduced in 43 patients and others 44, maintained the exclusion diet for over 60 days. In the nickel diet group, there was a recurrence of symptoms between the seventh and the twentieth day of the nickel diet. The second group who maintained the exclusion diet, continued without symptoms.

Another retrospective studies confirm that dietary nickel can be the chief trigger for provocation and persistence of symptoms in a subpopulation of patients with chronic allergic-like idiopathic dermatitis syndromes and nickel sensitization ⁷, ⁸, ⁹.

Previous experimental studies in patients with allergic contact dermatitis had demonstrated that systemically absorbed nickel can be the real cause for the onset of both secondary eruptions in those where a simple contact exposure cannot account for the distribution or the aggravation of skin lesions and, in some cases, of widespread dermatitis syndromes, which include a variety of clinical manifestations ranged from maculo-papular rash to flexural dermatitis, toxicoderma, and chronic urticaria ¹⁰, ¹¹, ¹², ¹³.

But still, the relationship between dietary nickel and systemic contact dermatitis remains controversial. The studies concerning systemically induced nickel dermatitis have been brought into questions because of some inconsistencies related to diagnostic procedures, diet, and doses of challenge ¹⁴.

Nickel allergy symptoms

An allergic reaction (contact dermatitis) usually begins within hours to days after exposure to nickel. The reaction may last as long as two to four weeks. The reaction tends to occur only where your skin came into contact with nickel, but sometimes may appear in other places on your body.

Once you develop a nickel allergy, however, you’ll always be sensitive to the metal and need to avoid contact.

Nickel allergy signs and symptoms include:

• Rash or bumps on the skin
• Itching, which may be severe
• Redness or changes in skin color
• Dry patches of skin that may resemble a burn
• Blisters and draining fluid in severe cases

Nickel allergy diagnosis

Your doctor can usually diagnose nickel allergy based on your skin’s appearance, and a recent exposure to items that may contain nickel.

If the cause of your rash isn’t apparent, however, your doctor may recommend a patch test (contact hypersensitivity allergy test). He or she may refer you to an allergy specialist (allergist) or a skin specialist (dermatologist) for this test.

Nickel allergy test

Subjects undergoing baseline series patch tests are specifically tested to nickel sulphate-hexahydrate (NiO4S.6H2O).

During a patch test, very small quantities of potential allergens (including nickel) are applied to your skin and covered with small patches. The patches remain on your skin for two days before the doctor removes them. If you have a nickel allergy, the skin under the nickel patch will be inflamed when the patch is removed or in the days after removal of the patch.

Because of the low concentrations of allergens used, patch tests are safe even for people with severe allergies.

Figure 3. Nickel allergy test

Note: The top photo shows a positive patch test (on the left), after a patch containing nickel was left on the skin for 48 hours. The lower photo shows nickel allergy from metal in clothing, such as a belt buckle.

Nickel allergy treatment

There’s no cure for nickel allergy. Once you develop a sensitivity to nickel, you’ll develop a rash (contact dermatitis) whenever you come into contact with the nickel metal.

It is essential to avoid skin contact with nickel-containing metals.

Treatment is often necessary for nickel dermatitis.

• Compresses. Dry up blisters with diluted vinegar compresses. Do not use these if the skin is dry.
• Use soothing lotions, such as calamine lotion, which may ease itching.
• Topical steroids. Apply topical steroid to the dermatitis as directed by your doctor.
• Antibiotics. Antibiotics may be necessary for secondary infection of nickel dermatitis (impetigo).
• Emollients. Apply soothing emollient creams frequently to relieve itch and dry skin. Using emollient creams or lotions, such as petroleum jelly or mineral oil, could reduce your need for topical corticosteroids.

Unfortunately, desensitization with injections or pills is not possible so the allergy tends to persist long-term.

Your doctor may prescribe one of the following medications to reduce irritation and improve the condition of a rash from a nickel allergy reaction:

• Corticosteroid cream, such as clobetasol (Clobex, Cormax, others) and betamethasone dipropionate (Diprolene). Long-term use of these can lead to skin thinning.
• Nonsteroidal creams, such as pimecrolimus (Elidel) and tacrolimus (Protopic). The most common side effect is temporary stinging at the application site.
• Oral corticosteroid, such as prednisone, if the reaction is severe or a rash covers a large area. These drugs can cause a host of side effects, including weight gain, mood swings and increased blood pressure.
• Oral antihistamine, such as fexofenadine (Allegra) and cetirizine (Zyrtec), for relief of itching. However, these may not be very effective for skin itching.

Phototherapy

This treatment involves exposing your skin to controlled amounts of artificial ultraviolet light. It’s generally reserved for people who haven’t gotten better with topical or oral steroids. It can take months for phototherapy to have an effect on a nickel allergy reaction.

Low nickel diet

This diet low in nickel-containing foods has been suggested to patients with severe contact allergy to nickel. Its efficacy is unknown. Nickel cannot be completely avoided from diet. Avoid nickel-plated utensils and metal cooking pots. Avoid drinking the initial flow of water from a metal tap.

Foods allowed

• Meat, poultry, most fish, eggs, milk, yogurt, cheese, quark, butter, margarine
• Cereals, bread, flour, rice, pasta
• Small servings of wholemeal flour, wholegrain cereals, wheat bran and wheatgerm
• Most vegetables
• Small servings of beetroot, cabbage, cauliflower, leeks , parsnips, potatoes, spinach
• Fruit such as bananas, and occasional apples and citrus fruit, raw and stewed
• Tea, coffee, soft drinks, cordials

Foods to avoid

• Canned food, especially spaghetti and baked beans
• Green beans, soya beens, broccoli, peas including split peas, canned vegetables
• Canned fruit, dried fruit, nuts, oatmeal
• Cocoa, drinking chocolate, chocolate

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