What is a jewellery allergy?
Jewellery allergy is a common cause of contact allergic dermatitis. Most jewellery allergy is caused by the metals nickel (see nickel allergy) and cobalt (see cobalt allergy) which is used in the manufacture of precious metal alloys. In less expensive jewellery, nickel is often used in the base metal which is then plated with gold or silver. Many people who believe that they are allergic to gold or silver jewellery are allergic to nickel, which can occur as a trace element in gold or silver or has been used in the manufacture of gold jewellery to whiten and strengthen the piece.
Jewellery allergy presents as dermatitis in places where nickel-containing metal is touching the skin. The most common sites of jewellery allergy are the earlobes (from earrings), the fingers (from rings), and around the neck (from necklaces); the affected areas become intensely itchy and may become red and blistered (acute dermatitis) or dry, thickened and pigmented (chronic dermatitis). Sometimes dermatitis later affects areas that are not in contact with jewellery, particularly the hands. Pompholyx is a blistering type of hand dermatitis that is prevalent in people with a previous history of jewellery allergy and may be due to contact with other sources of nickel such as coins and keys.
What other reactions to jewellery occur?
Jewellery reactions are not always due to an allergy to a specific metal. Other reasons for a rash on the site of a particular item of jewellery may include:
- Irritant contact dermatitis may be provoked by friction, surface particles and dirt on the metal, soap and water under the item or other non-metal components of the jewellery. Irritant reactions are more common in people that suffer from sensitive skin or atopic dermatitis
- Psoriasis and vitiligo can koebnerise and arise at a site or injury; for example, they could arise at the site of a tight watch strap, necklace or bangle
- A piercing site may be infected with Staphylococcus aureus, resulting in oozing and crusting (impetigo or wound infection).
Unrelated rashes should also be considered if patch tests prove negative.
How do I know if my jewellery contains nickel?
By looking at a piece of jewellery, it is very difficult to determine whether or not it contains nickel. One should assume that all metal jewellery has some amount of nickel in it unless it made of stainless (surgical) steel, is either 18- or 24-carat gold, is sterling silver, or pure platinum.
Gold for jewellery is typically measured in karats (also spelt carats).
- 24 karat (pure gold) contains 99.9% gold (plus 0.1% other metal).
- 18 karat is 75% gold.
- 12 karat is 50% gold.
- Nine karat is 37.5% gold.
To make up the rest of the metal, gold is alloyed with other metals. For people with metal allergy, particularly nickel allergy, the question is which metals are your gold jewellery alloyed with? Gold can be alloyed with many different types of metals which alter its hardness, colour and other properties. For example, yellow gold may be alloyed with silver and copper, while white gold is usually alloyed with nickel. Rhodium, a silvery-white metal related to platinum, is often used to plate yellow gold to make it into white gold. And even white gold with nickel is often rhodium-plated to make it appear whiter and shinier. Although the initial plating will protect you against any nickel in the gold, it eventually wears off over months or years. This leaves the white gold (alloyed with nickel) in contact with your skin.
There are three grades of silver for jewellery — pure silver, sterling silver and silver-plated. Pure silver is 99.9% silver but can be too soft and malleable to handle when making into jewellery. Sterling silver is 92.5% pure silver alloyed with copper. In some cases of sterling silver, a small percentage of other metals may be in the mix so traces of nickel may be present. Silver-plated jewellery is a base metal (and may contain nickel) that has been plated with a fine layer of silver alloy.
Who is affected by jewellery allergy?
Allergic contact dermatitis to metal jewellery may develop at any age. In most cases, this is due to nickel or cobalt allergy, and once it has occurred, it persists for many years, often life-long. Some people develop dermatitis (also called eczema) from even brief contact with nickel-containing items, while others after many years of wearing them without problems suddenly break out in a rash. This is usually confined to skin sites in contact with the metal but can spread more widely in severe cases.
Nickel allergy is more common in women, probably because they are more likely to wear jewellery than men, although this is changing. While nickel allergy is the most common jewellery allergy to occur, allergy to other metals used in jewellery is possible. However, it appears to be rare.
What is the treatment of jewellery allergy?
Treatment of jewellery allergy requires removing responsible jewellery.
How to avoid jewellery allergy
If you have a jewellery allergy, a dermatologist can perform a skin patch test to determine if you have a metal allergy. Once your nickel or cobalt allergy is confirmed, it is essential to avoid contact with that metal. The following tips may help when purchasing jewellery.
- Alternative white gold alloys are available based on palladium, silver and other white metals, but the palladium alloys are more expensive than those using nickel. High-karat white gold alloys are far more resistant to corrosion than are either pure silver or sterling silver.
- When having ears or other body parts pierced, have it done with a stainless steel needle and make sure your jewellery is made of stainless steel or either 18- or 24 karat gold.
- Look for jewellery that is hypoallergenic, i.e. made of stainless steel, at least 18-karat gold, sterling silver, or polycarbonate plastic.
- If you must wear earrings that contain nickel, add plastic covers made specifically for earring studs.
- If your wedding ring or another item of jewellery that you wear daily causes a reaction, you can ask a jeweller about having it plated in a non-allergic metal, such as rhodium or platinum. However, the coating will eventually wear off and need re-plating.
Test your metal items
Test your metal items to see if they contain nickel or cobalt. Obtain a testing kit from your dermatologist, pharmacist, or online.
Your dermatologist may have further specific advice, particularly if you are highly sensitive to nickel or other metals.