Blister (nonthermal) of left thumb, sequela

This code signifies a non-heat-related fluid-filled lesion on the left thumb, representing a long-term effect or complication of an initial injury or condition. It indicates that the blister is no longer an acute event but rather a residual problem.

Apply this code when documenting a chronic or persistent blister on the left thumb that is a direct consequence of a previous injury or condition, and not due to a recent burn. This would be appropriate for follow-up encounters where the blister is a lingering issue.

• Ensure the documentation clearly states the blister is on the left thumb and is a sequela, not an acute injury.
• Always code the underlying cause of the original blister if known and still relevant.
• Do not use this code for acute blisters or those caused by thermal injury.