The reason we ask your history is because, well, it's important

We recently had a patient who came in with a whole body reaction to a medication she had received a week ago. Her skin looked terrible. All over discoloration, thickening, swelling, painful lesions. Certainly she was having a reaction, but just how much was acute was difficult to discern. She was also African American and that makes it much harder (especially for me) to tell the extent of erythema.

We asked her if she had any other medical conditions, had ever had anything like this happen before, what her skin usually looks like. She pointed to an area on her wrist that was smooth and much lighter in color than the rest of her skin and said that her skin always looks like that. We admitted her for fear of SJS/TEN (really bad necrotic skin conditions that can be due to drug reactions).

Later we called her primary care doctor to find out that she has a chronic skin condition and has been seeing a dermatologist for years.

........

So you just happened to forget that you have a chronic skin condition and see a whole separate doctor for YEARS to treat it? That just happened to slip your mind when we specifically asked you what your skin normally looks like and if you have any other medical conditions??