Blister (nonthermal), left knee, initial encounter

This code signifies the presence of a fluid-filled lesion on the left knee that is not caused by heat, cold, or chemicals. It indicates a primary or initial episode of care for this specific condition.

Apply this code when documenting the first time a patient presents for treatment of a non-burn-related blister on their left knee. This includes blisters caused by friction, pressure, or other mechanical trauma.

• Ensure the documentation clearly specifies "left knee" and confirms the blister is non-thermal in origin.
• The "A" in the seventh character indicates an initial encounter for active treatment of the blister.
• Do not use this code for blisters resulting from burns, frostbite, or chemical exposure; those have specific codes.