Thank you for sharing your question with the EmpowHER community.
My first concern would be whether your skin condition is resolved or not. Have you had a dermatologist look at it? Does the area still itch? Has any keloid formed on the scar ? Because if so, it is not advised to tattoo over it. Also, it's not a good idea to tattoo your scar if it is less than 1 year old, and any portion of it is still itching, infected or red.
With any tattoo comes the risk of complications like, risk of infection and allergic reaction to name a few. It's best to discuss that area with your doctor and your tattoo artist so you can determine what's best.