This poem is an expression of a troubled person's innermost  turmoil, as he always feels a constant eerie sensation of something crawling inside his skin. 

"Crawling!"

"People!"

Which often symbolizes their deep inner fear, anxiety and 

"Pain!"

The person usually doesn't know the origin or the cause of this feeling.

All they feel is the isolation and sheer Hopelessness in their search for life's answers.