When we take a medical history, there is a modern tendency to concentrate on simply listing symptoms. This is evident in many EMR notes, since the number of items in a medical history or review of systems for many years has driven reimbursement.
This, and clinician compulsion to quickly get to the diagnosis in a time pressured visit, has kept us from letting the patient tell their story.
The order in which symptoms appeared is an important part of solving a diagnostic dilemma.
A simple example is the mysterious rash I read a case description of a while ago. Someone had an itch that turned into a severe rash on one leg and later developed a similar rash on the other leg. The timeline (if I remember correctly) revealed that a harmless itch was first treated with a cortisone cream to no avail and later treated with topical neosporin. This worsened the itch and caused a local allergic reaction. Rubbing one leg against the other during sleep exposed the other leg to neosporin, which the patient was by now allergic to. This case made it all the way to the medical journals. A simple question, like “tell me what happened, from beginning to end” would have solved this case very quickly.
When a patient is on multiple medications and has a new symptom that could be a side effect or interaction, the timelines of symptoms and treatments can sort things out. In my experience, patients aren’t usually able to recall which drug was started exactly when. Modern EMRs don’t display a graphic medication timeline the way our old paper charts used to. For this reason it takes more work than our patients would expect to correlate medication stops and starts with symptoms.
My 2011 post, A Deadly Interaction, illustrates how the stopping and starting of statin drugs can severely affect INRs in patients on warfarin, sometimes to the point of causing death. In the case I saw, the patient fared better, but it took the timeline to understand what had happened.
Speaking of statin drugs, I’ve lost count of the many times patients ignore their own timeline. People will say, “I think the medicine is causing my legs to hurt”. I then often get a positive answer when I ask, “did they hurt before you started the medicine?”
A dry cough from lisinopril and other ACE inhibitors is another case where I try to tease out the timeline. But if a patient with a preexisting cough still blames the medicine, I don’t argue the point; I just move on.
Twice so far this year I have seen a diabetic suddenly present with dramatically increased blood sugars. In both cases they had decided to eat healthier on the advice of helpful relatives and increased their fruit consumption. These patients had been diabetics for a long time, and somehow had forgotten that if something tastes sweet, it probably raises your blood sugar.
The detailed timeline is time-tested tool in making a correct diagnosis, just like the broad view of asking “what else is going on”.