Blister (nonthermal), left ankle, sequela

This code signifies a non-burn-related blister located on the left ankle that is a sequela of a previous injury or condition. It indicates a chronic or late effect of an initial insult, rather than an acute presentation.

Use this code for patients presenting with a persistent or recurrent blister on the left ankle that is directly attributable to an old injury, surgical site, or other resolved condition. This is appropriate when the original cause of the blister is no longer active but its effects are still manifesting.

• Ensure documentation clearly links the current blister to a prior condition or injury.
• Verify the blister is specifically on the left ankle and is not thermally induced.
• Do not use for acute blisters; the "S" seventh character denotes sequela.