My dermatologist said that it was not uncommon not to find a cause. I still have the patches on my legs. My doctor told me that the spots may take a long time to go away or sometimes they may not go away. He prescribed two topical solutions which needless to say did not work. Marks on the legs, whether from erythema nodosum or anything else, can take many months to disappear.
Treatment is of little value.
I agree with your doctor that, despite the x-rays and blood tests we usually do, the cause of erythema nodosum is usually not found. Dr. R Information contained within this forum is intended solely for general educational purposes and is not intended nor implied to be a substitute for professional medical advice relative to your specific medical condition or question. Only your physician can provide specific diagnoses and therapies. All rights reserved.