Anna was a clinic patient in the Season 5 episode Joy to the World. She was portrayed by actress Alix Korey.
Anna came to the clinic and was seen by House. House was on his very best behavior as he was trying to prove to Wilson that he could be so nice to a patient that one would buy him a present.
Anna told House that her asthma had not been improving. She insisted that she had been using her inhaler and goes through one a week. Knowing that the most likely cause was misuse of the inhaler, House asked her very politely if she had been using it properly. She said that she knew how to use it and that she wasn't an idiot. House then asked her to demonstrate it, at which point she pointed the inhaler at her neck and pressed the top; he smiled, since she had just proven she was an idiot.
Anna then walked out of the clinic in a huff, apparently due to House's unseen response. One of many possible insults could have been "You do know its called an inhaler, meaning in INHALE air; it's not the latest expensive perfume."