I fell last Wednesday and hit the inside of my upper arm on the corner of a wood cabinet. As expected, I ended up with a horrible purple and red bruise the size of my fist. However, now there is a welt about the size of a quarter under the skin of the impact site that is extremely tender. Do I keep applying ice and heat? Can I wrap it lightly during the day so that it does not directly rub on my side?
Hello, I have studied your case.  I think you have developed collection of blood under the skin. It is called hematoma. It is very painful and needs to be treated. Furthermore, it would be better if you get x-ray of the hand also as some time it can be a hairline fracture. You should apply hot water fomentation and take Broken tablet if pain is there. Also, you can apply compression bandage. I hope this answer will be useful to you. Thanks