Blister (nonthermal) of lip, initial encounter

This code signifies a non-burn-related fluid-filled lesion on the lip. It indicates a localized collection of fluid under the epidermis, not caused by heat, chemicals, or radiation, and is being treated for the first time.

Use this code for patients presenting with a blister on the lip that is not due to a thermal injury, such as a friction blister or a blister from an allergic reaction. Documentation should clearly state the presence of a non-thermal blister on the lip and that this is the initial encounter for treatment.

• Differentiate carefully between thermal (burn) and non-thermal blisters; thermal blisters are coded differently.
• Ensure documentation specifies "initial encounter" for appropriate seventh character assignment.
• Consider additional codes for the underlying cause of the blister if known and clinically relevant (e.g., allergic contact dermatitis).