According to the official gov.uk website which is basically fact it states if you have suffered multiple fits/attacks in the past you must be free from attacks and medication for 10 years plus have no more than a 2% chance of having another fit/attack.
For one off fits/attacks then the time to be free of fits/attacks and medication is reduced to 5 years.
The fact your epilepsy happened as a child would not alter the conditions of the requirements.
You may well be expected to undergo a more intensive medical because of your past.