Diamonds are all fun and games - right? Until they aren't. Anyone who had woken with the dreaded "ring rash" knows sometimes the diamond ring you love can by your enemy.
Now, there are two main causes of ring rash.
The first is simple irritation from soap and water under your ring. If you wash your hands (and we hope you do) probably don't know notice but sometimes water and soap gets stuck under your ring and can cause a rash. This is a pretty easy solve. When you can it's always a good idea to take your rings off as you wash and dry your hands so can make sure to get the area under your ring completely dry and clean before you put your rings back on. This kind of rash usually goes away with a topical steroid cream like Cortaid and can be prevented by just making sure that area is really dry after washing your hands.
The second type of ring rash is from an allergy to the metal. This is one is not as easy to cure (obvi). Most 14k and 18k gold alloys contain some nickel, and a nickel allergy can be fairly common. Many people don't know they have a nickel allergy because it's not like they are touching nickel in their every day lives until they have a wedding ring on! If you suspect you have a nickel allergy it's a good idea to confirm with demonologist before you freak out you are allergic to your diamond ring.
If you do have a nickel allergy and having a ring made, you should inform your jeweler so they can use an alloy that does not involve nickel. If your existing ring has nickel in it, some people have had success rhodium plating it to provide a barrier between the nickel and the skin.
It's always a good idea if you have ring rash not to jump to conclusions and check with your doctor!