Q: Please help with coding this scenario: We have a patient with a chronic wound due to constant, compulsive scratching. The wound measures 3 cm x 1.5 cm x 0.3 cm deep. Is this appropriate for trauma? How deep is "superficial?" A: The question to ask to determine the correct code is "How did the wound originate?" advises coding expert Joan Usher of JLU Health Record Systems in Pembroke, MA. If the wound started due to compulsive scratching, this would be coded as a trauma, open wound to the (location), she says. If this is now chronic in nature, it should be coded to late effects of open wound 906.0 to 906.1. If the wound originated due to surgery, it would be coded to non-healing surgical wound 998.83.