My dd2 (PSB-perfect second born) has a skin reaction to strawberries, blueberries and kiwi (I guess they must be relations), she seems to be ok if she eats them in something (ie no bad poo's), but if she gets some on her skin the reaction seems to be similar to your dd's, and last week her sister gave her a piece of kiwi (which I took away quickly!), but she rubbed her eye and it swelled up really badly. We gave her some Piriton (Supposed to be from 1 year old, unless dr recommends)and the rash and swelling went down really quickly.
I hope your lo is ok, and I would agree that it is probably a good idea to try little bits of aubergine (or related foods), in a little while, to see if she has grown out of it.