4. You/your child will have two, one time biopsies or skin samples taken by a dermatologist. Skin areas will be numbed with lidocaine and a 4 or 5 millimeter (or approximately 0.15 to 0.19 inch) sample will be taken in two different locations. The dermatologist taking the skin sample will use every effort to choose an area that can be covered by clothing or kept out of sight to others. The doctor will either use gelfoam or one stitch/suture per biopsy to seal off the area, which helps with healing and preventing bleeding. If a stitch is placed in the biopsy site, another visit about 7-10 days following the procedure will be necessary to remove the stitch.