The end of physical diagnosis
The physical exam is increasingly becoming a formality, as technology takes a bigger and bigger role in diagnosis, as summaized by Dr. Sandeep Jauhar in this Perspective piece in the NEJM.
For example, when I see an otherwise healthy child with peanut allergy, what exactly do I learn from the examination? Almost always the answer is little or nothing. Occasionally I can pick up evidence of environmental allergies on eye or nose exam, but that is the exception. For residents during their training, when admitted patients have already been examined several times and had multiple tests, the answer is even less.
In general, technology is increasingly dominant in defining actual pathology because it works so well. As Jaudhar notes, a chest X-ray is better at diagnosing pneumonia than "Sir William Osler with a stethoscope." As a medical student, I used to hate what I called "retrospective physical diagnosis." Patients with aortic regurgitation (when blood flows backwards from the aorta into the heart during diastole, when the heart is relaxing) have a "to and fro" murmur you can hear by listening to the femoral pulses. More than once on a cardiology rotation, I was sent in to listen for this fascinating murmur. Of course, not once had it been used to diagnose aortic regurgitation! Instead, once the echocardiogram revealed AR, everyone went back to listen. How useful is that?
What I think the exam is best for is picking up abnormalities and ruling out badness, especially in primary care where it can help guide use of technology. A normal neuro exam in a patient with headache is very reassuring.
And as I've noted, sometimes one or two abnormalities on exam can lead you to find something unexpected.