Feeling bugs crawling on your skin is a neurological symptom called "formication". In combination with other neurological symptoms such as night terrors and sleepwalking, and with the irritability and outbursts, you might want to consider getting a referral for a neuro consult from your pediatrician. 
Not every problem gifted children experience is due to giftedness.
Of course they are not only due to giftedness.  
I think mountainmom did say that originally too.  She commented on my response and I commented back.  that's all.