The only time mine vanished (to my surprise) was when I had a course of strong antibiotics and steroids to treat a bad chest infection. It came straight back afterwards (this was over 20 years ago).
It was somewhat helped by a long course of oxytetracycline antibiotics (sp?) prescribed for it by doc who said it was infected skin (?????????). Came straight back after and a second course had negligible effect. (Again, this is years ago)!