How often does this happen to you? You're in a social situation, minding your own business. Someone walks up to you, hikes up his or her shirt, pants, or dress to reveal a lump, bump, or rash, and without a second thought, asks, "What's this?"
I call it "What's This Rounds." My wife and I joke about it. Each time we enter a gathering, one of us invariably will say, "I wonder what we'll see at 'What's This Rounds' tonight!"
It can happen anywhere: at a party, a ball game, or while we're strolling down the street. A man once stopped me in front of the T. Rex skeleton at the American Museum of Natural History in New York to inquire about a dermatofibroma on his leg. (To this day I have no clue who he was.)
Incredibly, I've had "what's this" phone calls as well. (Why anyone thinks I'll know what "this" is, without seeing it, is completely beyond me.) These days, I'm getting "what's this" e-mails, too - from patients and physicians!
It happens to all of us, and we joke about it. But what do you do? You don't want to appear rude or aloof; but there are obvious legal and ethical issues to consider, especially when the individuals are not under your care (as they almost never are).
Does a casual "what's this" question create a physician-patient relationship? Do you owe a "duty of care" to such people, just because they've asked you to identify a bump or rash?
As so often happens, the law in this situation is inconsistent, and unreliable; few if any written statutes directly address the issue, and courts have gone both ways.
Some judges have ruled that "informal consultations" are analogous to "Good Samaritan" encounters (although Good Samaritan laws seldom specifically cover such situations) and in the same way, cannot create a liability. Other courts have found that existence of a doctor-patient relationship has to be decided on a case-by-case basis.
Obviously, a lot depends on where you practice; legal precedents vary state by state, and it may be wise to review the situation in your state (or ask your attorney or malpractice carrier to do it for you).
Nevertheless, some basic guidelines are in order, no matter where you live.
When a relative or acquaintance asks my advice, whenever possible, I answer that this isn't the time or place. They need to come to my office (or see their own doctor) where they can be examined with the proper equipment and lighting, in proper privacy.
When I must give an answer, I always preface it with a disclaimer: We are talking informally, as opposed to professionally, and the person asking should not be relying on my advice, because I am not legally his or her doctor (as those are the two essential requirements for legal liability).
It goes without saying that I never discuss other patients, or matters outside my field of expertise, and I never prescribe medications informally.
When a colleague grabs me in the hall and asks about treating a patient I haven't seen, I preface it with a similar disclaimer. I emphasize that my advice is necessarily general and abstract because individual situations vary, and I can't really be more specific without examining the patient myself.
When the request is via e-mail (as it is, more and more often), I have a prepared, template response suggesting that a comprehensive evaluation is necessary, so that any specific diagnosis and treatment recommendations will be based on a full understanding of the patient's specific medical history, and not on secondhand or incomplete information.
If the patient already has a specific, well established diagnosis, I may suggest some potential treatment options in general, abstract terms. At the end of the template, my lawyer added a sentence emphasizing that my response does not imply a formal consulting relationship, nor am I advocating a particular course of action.
Some lawyers suggest keeping a record of informal consults in an office folder designated specifically for that purpose. You can't create a chart for a patient you have never seen, of course, but the doctor soliciting your advice may well have made a note in the patient's chart about it.
In the absence of any documentation by you, that will be the only written record. To protect yourself, you may wish to write your own note in a "miscellaneous" file that does not imply a doctor-patient relationship, but allows you to document your side of the conversation, emphasizing the informal, nonspecific, and inconclusive nature of the advice.