It seems I did not have the flu because something very strange happened to me. I was achey and ran a fever between 99.5 and 100.1 for about 4 hours then all of the sudden it went away, so I don't think it was the flu because when I get the flu with a fever it usually lasts for days, Also with me the flu usually comes along with sore throat and cold symptoms. Can Idiopathic SFSN and it's underlying condition depending on what it is, cause flu like symptoms and fever? This was so strange because I almost never get a fever. Thanks, Jan

Autoimmune disease may cause a fever too.

Lupus is one example.

http://www.emedicinehealth.com/lupus...s/page3_em.htm

Sometimes your immune system may abort a flu. If your
vit D is at a good level, it may nip things quickly.