Blister (nonthermal), unspecified knee, sequela

This diagnosis code indicates a non-burn related blister located on an unspecified knee, representing a residual condition or complication from an initial injury or disease. It signifies that the blister is not an acute event but rather a lingering effect.

This code is appropriate for documenting a patient presenting with a blister on the knee that is a long-term consequence of a previous injury, infection, or other dermatological condition, and the specific knee (left or right) is not documented. It should be used when the blister is not due to heat or cold exposure.

• Always seek to specify the laterality (left or right knee) if documented to use a more specific code.
• Ensure the medical record clearly indicates the blister is a "sequela" or a "late effect" of a prior condition.
• Do not use this code for acute blisters; instead, use the appropriate acute blister code.