What to say when you don't know?

How about "I don't know"?
It seems simplistic but its not. A few years ago Medchi, the Maryland malpractice insurer sponsored a course to teach physicians how to say sorry.
I don't think most patients realize how hard it is for many doctors to admit when they don't know the answer.
Part of the problem is that the doctors feel they are not living up to the patient expectations and so cannot admit they don't know.
In my opinion there really is only one way to proceed. Admit you don't know, explain to the patient why there is a question and come up with a strategy for resolving the issue.
As we all know you can not fix a problem until you identify what it is. This may require a second opinion or additional tests.
The problem comes sometimes when the expert opinion suffers from the inability to say "I don't know".
For example this often occurs with dermatology, a patient may have been sent to try to get an exact diagnosis but often a biopsy is done and the report comes back without one.
At this point the dermatologist should return the patient to the primary care doctor and say honestly "unfortunately, I don't know what this is. Here are some suggestions as far as possible therapies or management".
Great. Thank you very much.
This is better than trying all kinds of products and therapies, having the patient run from pillar to post and paying high copays to no avail.
I have a patient at the moment who walks around with a scarf to cover her face because she is so embarrassed by her skin.
We had cleared her skin of all the acne but she had one spot with an ingrown hair that she kept picking. It got bigger and bigger.
I sent her to the dermatologist to get the hair removed with laser. It went well initially, but after that area was done she and the dermatologist decided to do a wider area for hair removal and start using different products. When she reacted to those, they decided to try some others. That did not work so after 4 more products she sought out a second opinion dermatologist who wanted to try more stuff.  Now her face is a disaster.
After 3 dermatologists she recently came back to see if I can get her back to where she was before she went to the first dermatologist. After that, we shall work on the scars.
What makes it harder for some doctors with big egos to admit they don't know, is that patients comb the internet and act like they know everything. This can be a slippery slope, for both doctor and patient especially when accepting on speck that the patient's own diagnosis is correct.
I am absolutely an advocate for patient education and information, so I encourage patients to learn as much as they can but beware of self diagnosis without expert input.
A patient told me the other day that she had read a woman's blog where the person claimed to have developed invasive cervical cancer within a year of having a normal pap smear. She now wants to have two pap smears done a year just in case. I told her that would not be appropriate. All I can say is that based on the pathology of cervical cancer that sounds next to impossible.
I know nothing about the writer or her motivation and I told the patient so. "But why would she write it if it wasn't true?"
I answered truthfully: I don't know.