The phrase "touched a sore spot" means to say or do something that has caused discomfort, offense or upset to another person, usually touching on a sensitive or delicate subject. There are many synonyms for this phrase that can be used interchangeably, including "hit a nerve", "struck a chord", "pushed a button", "rubbed salt in the wound", "picked at a scab" and "trampled on someone's feelings". These synonyms all convey a similar meaning and can be used in different contexts to describe situations where someone has unintentionally or intentionally caused pain or irritation to another person. It is important to be mindful of others' feelings and avoid touching on sensitive topics unnecessarily.