I believe that strange sensations that feel like bugs crawling under your skin, twitches, and shocks or what feels like pins or zaps to your skin as well as itching ears or strange sensations in your mouth and throat is usually related to inflamed nerves in your body. Inflammation plays a huge role in most cases. I believe there are cases of it actually being parasites such as scabies, but usually it is you nerves from some sort of disease action. Very often though the person does have intestinal parasites as well and can actually be the very reason that this inflammation started in the first place. Guillian Barr syndrome can be caused by infection that results in inflamed nerve endings. The herpes virus can cause nerves to inflame and give strange sensations. Any type of Autoimmune Disease can also give you strange sensations, since autoimmunes disease simply translates as body inflamation which doctors don't clarify properly. Guillian Barr syndrome is said to be an autoimmune condition, but is caused by infection and can go away. I believe there is a strong gastrointestinal relationship to the inflammation as well as the sensations. It can make you feel crazy.
I went through all of these sensations when diagnosed with autoimmune disease. I did find I also had intestinal parasites after herbal cleanses, but it wasn't parasites that were crawling on my skin causing the sensations, it was simply overactive and inflamed nerves. I did develop cancer a few years later. It is very important to alkalize, supplement with minerals as many times there is a few deficiencies esp magnesium, and enhance digestion and eat right. Getting rid of intestinal parasites is a big part of helping your digestion. Make sure to get plenty of omega 3's as well to control and combat inflammation. Mix 1/2 cup cottage cheese with a tablespoon of flax seed oil to get your omega 3's. Cottage cheese gets your body to absorb the flax seed oil better. Also get plenty (and I mean tons) of vitamin C, as vitamin C reduces body inflamation as well. Flax seed oil and vitamin C are POTENT and healthy nutritional anti-inflamatories.