If you notice an itchy red rash, bumps, scaly skin or blisters where fake jewelry touched your skin, there's a decent chance that you're allergic to one of its components. A lot of jewelry contains nickel, which is a common allergen. Plus, costume jewelry has all kinds of components (including nickel) that can trigger your allergies. An allergy to fake jewelry falls under the category of "allergic contact dermatitis." This means that your body misidentifies certain substances and thinks they're harmful, even though they're not. Once your immune system makes this mistake, it will continue to make the same mistake every time you touch the substance that you're allergic to.
Allergic symptoms like rashes are the result of a chain reaction in your body. First, the allergen (for instance, nickel) touches your skin. Then your immune system registers the contact and sends out an alert to produce antibodies called immunoglobulin E. The antibodies then signal your mast cells to attack the "invader," which they do by releasing a swarm of chemicals. Among these chemicals is histamine, which is responsible for most of the allergic swelling, rashes and other symptoms. Generally, the visible allergic symptoms will start out where your fake jewelry touched your skin. If your reaction is severe, the rash might spread to other parts of your body.
Unfortunately, there's no way to cure allergies. The best way to prevent an allergic reaction to fake jewelry is to avoid wearing it. If you want to figure out exactly what substance in your jewelry is causing the reaction, your doctor can help you determine the allergen. Then, you can opt to buy jewelry that doesn't contain that substance. If you do have a reaction to fake jewelry, remove the offending accessory. Over-the-counter antihistamines are often helpful in treating the symptoms.