Why would you be willing to take the chance of an infection when you already have trouble healing? Is your life worth that little? And for what? A tattoo, something that is completely unnecessary.
You should be thankful that there is a medication that can help you with healing; 50 years ago it didn’t exist and when you got a wound that didn’t heal you usually died of infection or blood poisoning.
Please don’t take the chance, you would be putting your health and life in jeopardy.