Blister (nonthermal) of left front wall of thorax, sequela

This code signifies a non-thermal blister located on the anterior aspect of the left chest wall, indicating a long-term effect or complication of a previous injury or condition. It describes a residual blister that is not due to heat, cold, or chemical exposure, but rather a lasting consequence.

Use this code when documenting a patient presenting with a persistent, non-healing, or recurrent blister on the left front of the thorax, where the original cause of the blister has resolved but the blister itself remains as a sequela. This would apply to situations where the blister is a chronic manifestation of an earlier, non-thermal injury or dermatological condition.

• Always assign an external cause code (V00-Y99) to describe the original event that led to the sequela, if known.
• Ensure the documentation clearly specifies "left front wall of thorax" and "blister (nonthermal)" to support this specific code.
• Distinguish from acute blisters (S20.31- or S20.32-) by the "S" seventh character, indicating a sequela.