As Winston sits before the blank diary page, his ulcerous sore " begins it itching unbearably." For what could this ulcerous sore be an objective correlative

Sitting before the blank diary page, Winston is about to commit a crime.

It is not surprising that at this moment, his sore begins to itch unbearably. It is a reminder of his guilty conscience and of the crime he is about to commit. It is his internalization of Big Brother, reminding him that any thought not in support of Big Brother is a crime.