Given the pattern of attacks and response to John of Ohio, a viral explanation seems at least likely. I'd like to get an antibody test, but my GP doesn't feel qualified to interpret any results, which is fair. She referred me to a doctor who specializes in allergies and immunology. But his website is all about allergies. I have no idea what type of doctor to ask for a reference to. I tried to find someone who is a virologist, but struck out. Any suggestion about specializations is very, very much appreciated.