The Sami people of Scandinavia have 300 words for snow, while English has only a fraction of those. The “sense of touch” describes the entire tactile system, one of the five ordinary senses, complex systems often inadequately described by single words: sight, sound, smell, taste and touch.
Imagine….an entire system referred to simply as “touch”. Yet, it’s a very varied sensory world that is encompassed by that simple word “touch” . 
I often work with people who are hypersensitive to touch and/or have difficulty identifying the different kinds and qualities of touch. Many children I have known have confused light touch with pressure and pressure with light touch, experiencing light touch as painful and deep pressure as tickling. One autistic boy I know screamed “pain” before any physical touch occurred.
A wealth of information about the world comes to us through our sense of touch, and when we can’t rely on that information because it is inaccurate or incomplete, it is quite understandable that there would be confusion and anxiety.
Skin serves as a protective barrier between our internal systems and the world around us. The tactile system or touch system sends sensory information such as heat, cold, pain, pressure and movement from receptors in the skin (as well as tissues, muscles and bones) to the central nervous system The sense of touch lets us know that our feet are touching the ground when we stand and walk, and along with the adjunct somatosensory system, we don’t have to look at where we are stepping or at what we are touching. We would be quite anxious if we didn’t have this kind of information, or couldn’t rely on its accuracy.
The tactile system is a ‘first alert” system. The sense for light touch is the most primitive aspect of the tactile system for its ability to ‘sound the alarm’ to danger that something or someone is touching us. Without pain, heat or cold receptors we wouldn’t sense when we were cut, being burned or freezing.
With too much or inaccurate tactile information, it would be very difficult to pay attention to anything else. What would you be able to do if it felt that you were always itchy? or felt that your skin had been rubbed raw? How could you write or draw if you couldn’t tell how you were holding a pencil or a brush or how it was resting on the paper?
The same embryonic tissues that become our nervous system become our skin. All of the tactile receptors are actually modified dendrites. The skin, our largest organ, has millions of tactile receptors. There are four main types of tactile receptors: mechanoreceptors, thermoreceptors, pain receptors, and proprioceptors. There are rapidly adapting receptors (e.g. light touch, pain) and slowly adapting receptors (e.g. pressure). The brain receives superficial sensations, such as those for pain, temperature and simple touch, and deep sensations for sensing such things as position, movement and vibration.
Without our ‘simple’ sense of touch, we wouldn’t know how to move, how much pressure to use, whether we are on the earth or not, if we are in certain kinds of immediate danger, and would lose out on some of the most pleasurable experiences possible.