Just as others have said, the symptoms are always there, but more bearable some days than others. Usually there seems to be absolutely no rhyme or reason to the changes. However I have noticed that stress makes things much worse. For instance I always come back from holidays now with either (a) a rash, (b) a nervous twitch, (c) red eyes that make me look as if I've been crying the whole time, or (d) any combination of these.