Accidental exposure of the wound the diesel fuel can cause pain and stinging. If this happens, you should wash and rinse it off. With a brief contact of the fuel on the wound, I do not think there will be significant long term carcinogenic effects from the exposure.
Keep the wound clean. You can wash it with antiseptic solution or water. If you have an antibiotic or antiseptic ointment, you can apply this on the wound. You should seek medical attention if the wound becomes red and painful and if there is pus discharge, as this may indicate the wound has become infected.
