Trypophobia

Trypophobia is the fear of small holes in living things or objects. This might sound like an unusual phobia at first, but people who experience it say that the holes or circles they see on an object resulted in feelings of skin crawling, disgust or nausea.

Many diseases and illnesses can result in sores or blisters on the skin (eg. Chicken Pox or Measles), which is one potential reason why a person may become averse to seeing "holes". And in nature, things that may be dangerous can be covered in spots such as poisonous mushrooms or berries.