Well, most of the folks I've known on here over the last 10+ years have been on plaquenil long-term and I've never heard of this as a side effect before... so whatever it is, my bet is that it is NOT related to plaquenil.
I don't think it's really anything to worry too much about
, but do mention it to your rheumy when next you see him/her.
Lynnwood, Lupus & Sjogren's Moderator, Dx: 2002DIAGNOSING LUPUS & HW's LUPUS 101
"Life is far too important to be taken seriously." - Oscar Wilde