In his book "The Civility Solution: What to Do When People Are Rude" (St. Martin's Press, 2008), P.M. Forni presents social quandaries and proposes civil solutions to them. He closes his book with a tipsheet on dealing with rudeness, composed by psychologist Arthur Ciaramicoli. If someone's being uncivil to you, consider these points, adapted from the tipsheet, before you react.
1. Don't personalize rude behavior. It's unlikely to be about you, even though it's directed at you.
2. Be aware that rude behavior comes from various sources (sleep deprivation, depression, stress, illness, insecurity, etc.).
3. Respond with calmness rather than behavior that escalates rude behavior.
4. "An eye for an eye" is a poor approach; don't turn another's insecurity into your own.
5. Self-righteous behavior only reflects poorly on you; don't use the opportunity to demean another.
6. Try to address the underlying cause of the behavior. ("I can see you are very stressed. Maybe I could help if you tell me what's bothering you.")
7. When necessary, set limits tactfully and assertively, not aggressively.
8. If the conversation remains irrational, know when to quit.
9. Don't assume rudeness is a permanent part of someone's personality. It is a pattern of rudeness (not one mishap) that determines character.
10. In the end, always let empathy - the ability to read others accurately - be your guide in understanding rudeness, knowing how to respond to a rude individual and knowing when to leave the scene.