Does a medical doctor have to tell if a patient self inflicts an injury?

[zoombug222]

Recently, I self-inflicted a burn, but I told everyone that it was from my toaster. I don't think the look of the burn is very convincing to be a toaster oven burn. A medical doctor would probably see the truth behind the wound. If he was suspicious of my self-inflicting the burn, would he be obligated to tell my parents? I am 18, but I still go to a pediatrician.
I plan on telling the doctor that I got it from a toaster oven burn, but if he wasn't obligated to tell how I really got it, then I would tell the truth and he may be able to help me more (if how I got the burn changes things diagnostically).
I am just worried of an infection, becuase the burn is starting to feel hot and I think that's a sign of infection.
I got the burn Sunday (5 days ago), if that helps with whether I should go to the doctor at this point, because I am debating on whether I should go.

[ibu guru]

The doctor needs to know the truth of how you got the burn because it may affect treatment. You have waited too long, and it very possibly is infected if red, swollen, hot to the touch, or not healing properly.

Medical confidentiality: you are over 18, so he cannot tell your parents. Doctors are required to report public health risks (e.g. STDs, tuberculosis, HIV/AIDS, other communicable diseases), gunshot wounds, suspected child abuse. For attempted suicide or intentional infliction of harm, he will refer you to psychiatric/counseling help. Do it.