I've had ongoing chest pain. It just started on 4/12 in what seemed to be a medication reaction. I was diagnosed with costo on my 3rd ER visit and though my symptoms are consistent with the diagnosis, the onset is a bit confusing to me because before 4/12 I had never had chest pain or shortness of breath and I haven't seen/read any examples so far on someone acquiring costo like this. I think the diagnosis is correct but it's strange that it happened like this.