Hi. I Have Very Long Hair (down To My Chest)

Hi. I have very long hair (down to my chest) for a guy, and every once in a while, it starts to itch and, when I itch it, it seems to start to excrete some sort of clear fluid? If I leave it alone, the itching stops, along with the excretion. But when I itch at it again, it starts back up. Is this some kind of dandruff? Or a rash perhaps?