If you have very sensitive skin or are prone to allergic reactions, you want to avoid lower quality metals like gold filled hoops & rings as well as any gold plated jewelry.
Skin sensitivity to solid gold jewelry usually comes down to the alloy content. Moving up to a higher karat may reduce the risk of having an allergic reaction. To create 10k, 14k or 18k solid gold, there needs to be alloy mixed in with 24k gold. The higher up in karat, the less alloy used to craft that karat of gold. This factors in to why there are much fewer people allergic to 18k than 10k.
We can't guarantee that there isn't any nickel in the alloy we use when melting the gold, which is usually the culprit when it comes to irritation. The alloy content should be a negligible amount in 14k gold for the majority of the population, but if you are very prone to allergic reactions, we always recommend purchasing 18k gold.