Hi Brenda,
With looking after your operated arm (the healing hand blister and the upcoming forearm biopsy) I'm not sure of the protective measures.
Nevertheless people here may know of some recommended care when an arm has had lymph surgery and needs a little more surgery.
I have arm lymphoedema for ages so I have yearly skin checks with all staying steady. If I needed a skin biopsy, even though it's not big surgery I guess I would phone my lymphoedema physio to find out the latest for looking after my arm.
I'm a good healer but figure I may as well have all the bells and whistles to take the pressure off the lymph vessels!
Best wishes with finding the info and for good outcomes and healing! Jenny xx