Corrosion of unsp degree of unsp thumb (nail), sequela

This code signifies a long-term complication or late effect resulting from a past corrosive injury to an unspecified thumb, including the nail. The original burn's severity is not documented or is unknown, and the specific thumb (left or right) is also not specified. This code is used when the acute phase of the injury has passed, and the patient is now experiencing residual problems.

Use this code when documenting a follow-up visit for a patient presenting with a chronic issue, such as scarring, contracture, or chronic pain, directly attributable to a corrosive burn of the thumb that occurred in the past. This applies when the initial burn's degree was not specified or is no longer relevant to the current sequela, and the laterality of the thumb is also not specified.

• Always use this code as a secondary diagnosis, following a code that describes the specific nature of the sequela (e.g., scar, contracture).
• Ensure the documentation clearly indicates a "sequela" or "late effect" of a past corrosive injury to the thumb.
• Avoid using this code for acute corrosive injuries; those require codes from the initial encounter or subsequent encounter categories.