I saw a young woman recently who is on isotretinoin for cystic acne and noticed a bandage on her left great toe. I asked about this and was told that a podiatrist had removed part of the nail because it was ingrown. Isotretinon can cause paronychia and excess granulation tissue in the nail folds and nail removal is not usually indicated in these cases. I asked if the podiatrist knew she was on isotretinoin and both the patient and her mother said "No."
"The more complicated your medical problems, the more fragmented your care will be. The average Medicare patient sees two physicians and five specialists a year. Those with a chronic illness see an average of 13 physicians a year. A Medicare patient with coronary artery disease sees ten physicians in six distinct practices annually. Indeed, the more physicians following someone after a heart attack, the lower the survival rates."
It is up to the patient to make sure his primary doctor (and other prescribing physicians) have all pertinent records from other providers.
An article on KevinMD summarizes this topic well: How to Fix Your Fragmented Medical Care.
Here is a full text article that addresses hypergranulation tissue and nail problems in patients on isotretinoin.