I have chronic idiopathic urticaria. recently, i noticed my hives worsen when i use tampons, but when i remove them, they get better. any ideas?

Hard to associate : You're saying that this is occurs with your systemic urticaria. If there's a relationship it may be due to a substance in the tampon. The other possibility is that you're using the tampon because it's it's your cycle and it may be related to something there and not to the tampon at all.

Triggers: Chronic hives have many triggers including hormonal changes such as those see with your period or pregnancy. A reaction to tampons is possible but unlikely. Try a different brand or try pads instead to what happens to the hives.