Eczema and Anti-Depressants

Anyone ever heard of someone getting eczema when withdrawing from an anti-depressant?  I am currently tapering off of Effexor XR and have developed eczema of the lips.  I spoke with a dermatologist who could not tell me why this would happen but advised hydrocortisone ointment, which -is- helping.

I would just like to know why this is the case.  The prescribing doctor seems to be clueless about the medication in general (one of the reasons I'm tapering off) and insists it couldn't be the medication (even though eczema is listed as a side effect!).

I've made the assumption that the Effexor is causing my eczema (rather than my toothpaste) b/c it only flares up when I've made another taper to a lower level.  By the end of the day, or at the latest the next morning, my mouth is red and swollen.  If left untreated, my lips will chap and peel.  They also itch!

That evidence, including the fact that eczema is a known Effexor withdrawal side effect, tells me it is likely the anti-depressant.

But why?