Reading recent paper (1), I thought on the problem of patient - physician relationship, what strengthens and what potentially weaknesses it.
In other words, how does a patient get an idea on professional level of his/her physician?
The paper I read says: "Also, respect for physicians has been replaced by distrust and unlimited demands". (1)
To me this sounds as a part of a general tendency. The population gets more information, sometimes of a doubtful quality, and uses it to challenge physicians. But on the other hand, this puts previously questionless position of a doctor in a new situation - they need to be well prepared! It touches everyone everywhere, also in research and medicine.
I think a good way to handle it would be asking where the person got the information, checking it and responding based on your expertise and relevant literature. Challenging your knowledge is not necessarily a bad thing:)
(1) http://360.bio/news/20/1473354418889634/?utm_source=Newsletter_SE&utm_medium=email&utm_campaign=SE_Sep-09-2016/, Accessed 9th September 2016