Blister (nonthermal), right knee, sequela

This code indicates a non-heat-related blister located on the right knee, representing a late effect or complication of an earlier injury or condition. It signifies that the blister is a residual problem rather than an acute event.

Use this code when documenting a patient presenting with a blister on their right knee that is a long-term consequence of a previous injury, infection, or other non-thermal cause. This is appropriate for follow-up encounters where the blister is a persistent issue.

• Requires a seventh character "S" to denote sequela, indicating the blister is a late effect.
• Always sequence this code after the code for the primary condition or injury that caused the original blister.
• Do not use for acute blisters or blisters caused by burns or frostbite.