you could be picking up energy, as we go through our days we sometimes pick up negative energy. sometimes people act as a magnet to energy unknowingly charging your body with energy. when you touch something, you're grounding this energy. try meditating daily, cleanse the negative energy, and charge with positive energy. [breath in visualize/feel positive energy entering your body, breath out and visualize/feel negative energy] once you feel you have all the negative energy out of your body, visualize/feel a circle of silver/white/gold [whatever positive colour] light surrounding you, and shielding you from negative energy throughout your day. as i said, this should be done daily as a way to keep negative energy away.
if you still feel a build up, try balancing your chakra's. this will clear any negative gunk out of your system and help the energy flow better through your body.