Anna told House that her asthma had not been improving. She insisted that she had been using her inhaler. 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.
Anna then walked out of the clinic in a huff.