I heard that dry ice can be used to apply directly on keloid, similar to liquid nitrogen.I have one small keloid on chest, it just sometime made me feel pain and itchy before.Then I had 4 sessions treated by liquid nitrogen but it has grown back after that, even it turns be worse, it's larger (x3), more and more painful and itchy.It makes me lose all confidence.How can i do with dry ice?Is this safe to do by myself? If so how large can I apply it on my scar?A part or whole?Please help me.Thanks!