I searched “asked chatgtp”, hot water can flare up rosacea by inducing vasodilation.

In cholinergic urticaria the skin raised and itchy, my face also it’s become red after shower but I think it’s because the hot water causes vasodilation.

If you mean they skip you over like they do not engage with you in conversation, it’s highly likely that they are shy or just scared to take the first step.

When you are with your friends and someone don’t say hi to you or shake your hand, its under consideration and rudeness of them, it has no thing to do with you.