Shopworker Claire Slimman was stabbed with a hypodermic needle - after challenging a thief over a chocolate bar.
And the Poundland supervisor, who was stabbed in the stomach, had to wait for several agonising weeks after the attack by David Paul Reilly.
She had to have treatment and to wait in fear before she was told she had not caught Hepatitis.
Rebecca Young prosecuting told Leeds Crown Court that the incident happened at Poundland in Victoria Lane, Huddersfield, when Miss Slimman approached Reilly after he had already ignored another member of staff about paying for the Toblerone on November 5, 2014.
Miss Young said Reilly had been spotted rummaging in a display of chocolate after he was seen wandering around the store. The supervisor approached him but he waved the bar in the air saying: “Come and get it, take it from me.”
She said she thought that was odd for a shoplifter standing up to her in that way and hen suddenly lunged at her with his right hand.
She had to have vaccinations and had a stressful wait for the result of blood tests. “Happily she wasn’t infected with anything.”
Since the incident she had found it difficult to confront anybody in the shop when necessary.
Miss Young said Reilly was arrested and officers found six hypodermic syringes in his pockets.
The court heard he had 24 previous convictions for 80 offences including wounding and assault and had previously been made the subject of hospital orders under the mental health act.
Mark Brookes representing Reilly said the victim must have been terrified for some time as a result of what had happened but said: “I ask you to take into context what was happening to him at this time.”
He had stopped taking his medication, become homeless, was sleeping rough and stealing to feed himself.
Reilly, 43 of Church Lane, Moldgreen, admitted robbery and was jailed for 30 months.
Recorder David Gordon said there had to be an immediate jail term. “This was a very nasty and frightening incident.”
He has also been banned from Poundland or approaching Miss Slimman for five years.