See generaly Arse Hair Demon, Klingon Arse-Pinch:

1. A medical affliction involving an infestation of microscopic gnomes with the tendency to pull one's arse-hair at will;

2. A person who is constantly nervous and jumpy is said to suffer from this malady.

N.B. A sufferer of this condition would be micro...trichotillomanic, and the chronic syndrome is micro...trichotillitis.

A longer, alternate form of this word is actually one of the lengthiest words in the English language. Sadly, it cannot be published in the UD because its length is over 40 characters, but here it is, broken-down:
From the Latin: gnomo (having to to with gnomes), ultra-microscopic (very small), perianal (surrounding the anal area), trichotillitis (condition involving hair-pulling)

Alternate form- gnomo...trichotillomania, which refers to particularly bad cases, where the gnomes are under a psychological compulsion to pull as often as possible.

The complete, obsolete, historical form of the word would be:
gnomoultramicroscopic perianal trichotillomania (spelled without the spaces).

When some little bitchboy is acting like a little tiny pee pee poo poo baby and messing up the group plans.