A rash where a ring sits can be contact dermatitis: a red, itchy rash that appears when skin touches something that irritates it or that it is allergic to. Nickel is one metal that Australia’s dermatologists name as a cause of the allergic kind, and the Perth Mint lists nickel among the white metals that can be mixed with gold to make white gold.
General information, not medical advice. healthdirect says to see your doctor if you think you have contact dermatitis. healthdirect’s helpline is 1800 022 222, known in Victoria as NURSE-ON-CALL, and a registered nurse can be reached on it at any hour, on any day of the week. Read more on healthdirect: contact dermatitis.
Two kinds of reaction
healthdirect describes two types of contact dermatitis, and they behave differently.
Allergic contact dermatitis
- The immune system reacts to a particular substance, called an allergen.
- The rash is delayed: it shows up a day or so after contact.
- It can spread past the patch of skin that touched the trigger.
- healthdirect says that once you are allergic to an allergen, the allergy is for life.
Irritant contact dermatitis
- The skin is damaged by something it meets too long or too often, until it can no longer protect itself.
- The rash stays where the contact was.
- healthdirect’s list of causes includes water from washing the hands too often, and handwash, soaps and detergents.
Either kind can leave skin red, dry and itchy, and a severe case can weep or blister; long contact can thicken the skin and make it scaly. It is also possible to have both kinds at once.
Where metal comes in
The Australasian College of Dermatologists says the place a rash appears follows the place the chemical touched, and gives metal as an example: earrings or watch parts containing nickel can affect the earlobes or wrists. The College adds that this kind of reaction usually needs longer contact: Australian coins contain nickel, but people seldom hold them long enough to react, even when allergic to it. A ring, by contrast, can stay on the finger all day and all night.
Wearing something for years without trouble is no guarantee: the College says a person can still develop contact dermatitis to a chemical after long contact with no problems.
On the metal side, the Perth Mint names nickel, with silver and palladium, among the white metals that can be alloyed with gold to make white gold. So the alloy inside a white band is a fair question to put to the seller, and its answer is a description the seller has to get right (see Buying a ring: your rights). The carats and colours are set out in Gold carats explained.
How a doctor finds the cause
A doctor can diagnose allergic contact dermatitis with patch testing, which healthdirect says usually takes around five days. In order:
Patches on
Sticky patches carrying small amounts of possible triggers go on the skin, usually the back, for two days.
First reading
After two days the patches come off and the skin is checked for a reaction.
Second reading
You usually go back two days later, so the doctor can look for a reaction that came on late; some people need another reading a few days after that.
The College notes that prick tests and blood tests do not identify this kind of allergy, because it is a delayed reaction, and warns that some tests sold as allergy tests have no scientific basis. healthdirect says there is no specific test for the irritant kind; a doctor goes by the symptoms and what the skin has been exposed to.
When healthdirect says to see a doctor
healthdirect says to see your doctor if you think you have contact dermatitis. healthdirect also says to see your doctor if:
- a product you were recommended for the rash is making it worse
- the rash is widespread
- it appears suddenly
- the rash hurts
- along with the rash, you feel unwell or you have a fever.
Skin with contact dermatitis can become infected. healthdirect names two signs that mean a visit to your doctor: a fever, or pus in the blisters.
What treatment involves
healthdirect says treatment comes down to finding the trigger and avoiding it, after which the rash should slowly clear. The College gives the same picture for the allergic kind: once contact stops, the rash takes days to a few weeks to improve. A doctor may refer you to a dermatologist or an allergist, and may prescribe a steroid (anti-inflammatory) cream or tablets. For looking after the skin meanwhile, healthdirect suggests trying not to scratch, keeping nails short, and asking a pharmacist or doctor about products for dry, sore or itchy skin.
Read more
healthdirect’s page links further reading from the Australasian Society of Clinical Immunology and Allergy (ASCIA) on allergic contact dermatitis. The College’s page on allergic contact dermatitis covers causes, patch testing and outlook in more detail.