It is the Chicken Pox virus (which is a form of herpes) that goes dormant and lives in your nerve ganglion (anyone who has had the chicken pox can get shingles) and things like stress, trauma, ect can activate it, except that this time your body does not build imunity and you are prone to break outs for life.
Laz, I am looking into accupuncture, as I am already on antiviral meds and they are tearing me up, But I feel for your Mom, It feels like my chest is on fire!!!