What is horse chestnut extract?

Hi,
I am officially allergic (deathly, anaphylactic shock style), to walnuts and peanuts.  However, I always avoid any type of nut.  Anyways, I have been shopping around for a good moisturizer for my eyes, which are itchy and sensitive and red because of my regular hay fever (cats/pollen/dust etc.), and I found an eye gel that I really want to try, which can be found here, along with the ingredients:http://www.isabellacatalog.com/p/Hydrafirm-Eye-Lip-Gel.cfm

My problem is that in the ingredients, "Aesculus Hippocastanum (Horse Chestnut) Extract" is listed.  I'm worried about whether or not this is safe to put on my skin?  Even though I'm even sure if this is a real nut or not.  Even then, it's just the extract.  I need advice on whether or not this would be safe for me to use.  I would really like to use it, so any advice is appreciated!
Thanks,
Kyndal

[Lekajdes]

"Horse chestnut is LIKELY SAFE for most people when a standardized seed extract product is used short-term. Standardized products have been tested to contain exact amounts of a verified chemical. Look for products which have had the toxic substance esculin removed. Horse chestnut products can sometimes cause side effects such as dizziness, headache, stomach upset, and itching.

Pollen from the horse chestnut flower can cause allergic reactions. Rectal (suppository) use of horse chestnut may cause inflammation and itching in the anal area.

Raw horse chestnut seed, bark, flower, and leaf are UNSAFE and can even cause death when taken by mouth. Signs of poisoning include stomach upset, kidney problems, muscle twitching, weakness, loss of coordination, enlarged eye pupils, vomiting, diarrhea, depression, paralysis, and stupor. Accidental ingestion of horse chestnut requires prompt medical attention. Children have been poisoned by drinking a tea made from the leaves and twigs or eating seeds."
This is some information I gathered, but before using it, you should consult the doctor.