Green’s Dictionary of Slang

Spitalfields crawl n.

[the insanitary condition of housing in Spitalfields, East London]

(UK tramp) the squirming action of someone who is covered in lice.

[UK]T. Burke Nights in Town 223: Some of them [i.e. tramps] writhe in a manner so suggestive as to give you the itch. This writhe is known as the Spitalfields Crawl.