Blister (nonthermal) of unspecified thumb, sequela

This code indicates a non-burn related blister on an unspecified thumb, representing a residual effect or complication of an initial injury or condition. It signifies that the acute phase of the blister has passed, and the current encounter addresses a long-term consequence.

Apply this code when documenting follow-up care for a blister on the thumb that is not due to heat, cold, or chemical exposure, and the blister itself is a sequela. This is appropriate for encounters addressing scarring, chronic pain, or other persistent issues directly resulting from the original blister.

• Only use this code for sequela encounters; an acute blister would require a different 7th character.
• Ensure documentation clearly specifies the thumb is affected and the blister is nonthermal.
• If the specific thumb (right or left) is known, a more precise code should be used.