I have an 18 year old puppy who used to have a lump on her chest. I assumed it was a cyst because of her age and how it seemed evenly rounded and I could put my fingers around it. Recently, I realized the lump is no longer there. Instead, her skin feels dry and is very itchy any time I touch the area. There are no open wounds or scars. I was wondering if it could have burst? And if there is something I should do for her skin.