Blister (nonthermal), unspecified knee, subsequent encounter

This code signifies a non-burn-related fluid-filled lesion on an unspecified knee, indicating a follow-up visit for a previously diagnosed condition. It applies to blisters caused by friction, pressure, or other non-thermal etiologies, rather than burns or frostbite.

This code is appropriate for subsequent encounters when a patient presents for ongoing management, evaluation, or treatment of a non-thermal blister on the knee. This includes follow-up appointments for wound care, monitoring for infection, or assessing healing progress after the initial diagnosis.

• Ensure the documentation clearly specifies a non-thermal etiology for the blister.
• Verify that the encounter is indeed subsequent to the initial treatment of the blister.
• Do not use this code for blisters caused by burns (T20-T31) or frostbite (T33-T34).