Trypophobia is not a real phobia. Look at the official list of phobias, and this is not even on there. This is a word 4chan made up back in the day that ended up spreading to various parts of the web.

It is however a very real and natural reaction. Your discomfort (e.g. skin crawling, shivering, nausea, etc.) is an automatic reaction of the sympathetic nervous system known as horripilation. This, like goosebumps, are a legacy genetic trait that serve to protect us as a 'fight-or-flight' response to imminent threat. This sudden onset of sympathetic nervous system responses in your body are the result of a complex process in your brain that takes place when you visually analyze flawed organic texture.

There is a region on your brain called the somatosensory cortex which, just like the other cortical regions, is in charge of performing the higher level interpreting of the nervous signals that it receives from the thalamus.

In the case of the somatosensory cortex, it is very specialized on interpreting the nervous signals that come from and go to your sensory and tactile system. This cortical structure is so specific, that well-defined cytoarchitectonic regions deal with very specific parts of your body. Your brain has a whole area in this structure devoted to digesting the tactile data from your feet. It has another dedicated area for your ears. It even has quite larger (in comparison) areas for the tip of your fingers alone.

In essence, your brain is very good at keeping track of the where and how of every inch of surface of your body. When you see the picture of a hand in perfectly good shape, your occipital lobe relays the visual data it gets through the ventral stream into your somatosensory cortex and you relate and evoke 'truth' that you derive from such data. If the picture of such hand was shiny for example, you could easily relate and 'almost feel' the oily sensation in your own hand.

If the picture in question portrays the hand's skin as being very dry, you can relate and perhaps even 'feel' the scratching of the skin when you rub it. The senses, are the 'language' of your brain. When you see a flawed texture, the way in which your brain interprets it is by formulating and reenacting all associated 'feelings' about it. When it goes around trying to formulate holes in your tact for you to accurately digest this disturbing visual data, it overwhelms the somatosensory cortex by demanding it to portray data it can not process. The very X/Y coordinates for you to, say, 'feel' the depth of each hole, simply do not exist in your neurons' history.

The picture of the fingers display a severe burn lesion most likely inflicted by electric discharge exit wound. It is likely that the subject had an accident while handling high voltage. You can clearly see the carbonized bone at the center of each wound. You, at this very moment, are naturally not having a similar wound. You are most likely to be able to feel the tip of your own fingers, feel their warmth, the pulse of your blood, the lush red color and the texture of your skin. The disturbing wound picture has enough information for your visual cortex to try to 'draw' a charred bone in your somatosensory cortex so you can interpret the visual data and accurately represent the depth/distance/position information you are gazing.

People who do not experience any adverse reaction at all are simply reacting in the simplest possible way by deeming it ficticious, thus not relating, and have no horripilation reaction at all. People with a greater neural network plasticity go as far as formulate it either way, despite not being wounded, 'enacting' the actual lesion, inflicting the virtual wound, and triggering the sympathetic system's response in awe. There is nothing you can do to avoid this reaction (and perhaps might even go as far as to congratulate yourself for having a greater density of proprioception than others). But there is something you can do to get rid of the discomfort after experiencing the horripilation.

Quite simply, just go ahead and rub your own skin. With the full surface of your hand palms, go on and rub your arms, your neck, anywhere you feel the piloerection (goosebumps).

You will notice that the eeriness is actually replaced with a satisfactory sensation of comfort, because what you're doing is you're overriding the anomalous data that your visual cortex interpreted from the flawed texture picture, with real data of the hypothetic surface when, as you rub your own skin, and find out that in fact, you do not possess such lesions.

It's as simple as that.