Blister (nonthermal) of unspecified ear, sequela

This code signifies a non-thermal blister affecting an unspecified ear, representing a late effect or complication of an earlier injury or condition. It indicates that the blister is no longer an acute injury but rather a residual problem.

Apply this code when documentation clearly states a non-thermal blister of the ear as a sequela, meaning it's a chronic or residual condition from a previous injury. This is appropriate when the original acute injury has healed, but the blister persists as a long-term consequence.

• Always sequence this sequela code after the code for the original injury or condition that caused the blister, if known and still relevant.
• Ensure documentation specifies "sequela" or "late effect" to justify using the 7th character 'S'.
• Distinguish from acute non-thermal blisters (S00.42XA) and thermal blisters (T20-T25 series).