How can a skin allergen continue to do harm long after the allergen does not come into contact with the skin?

Several years ago I was injured just above my ankle in the front of my leg. I was under a doctor's care as a result. A friend suggested I apply vitamin E "ointment" around the wound to expedite healing. I applied it twice, and soon experienced intense itching and discoloration. It became unbearalbe. Of course I immediately stopped the use of the oinment. Regardless, I experienced the symptoms for weeks, as I waited to see a dermitologist for the problem. The skin eventually became broken with many reddish poc-marks that spread adjacent to the wound and a bit up my leg. After finally seeing the dermatologist, he prescribed a number of treatments (ointments), until finding one that worked. But scarring has been left behind. To this day--three years later--the former wound site is greatly discolored and not pretty. So, again, How can a skin allergen continue to do harm many weeks after the allergen does not come into contact with the skin? Thank you.

How can a skin allergen continue to do harm long after the allergen does not come into contact with the skin?
its called a type 4 allergic reaction where cytokines are involved.