Poisn by pertuss vaccine, inc combin w pertuss, undet, subs

This code signifies an adverse reaction or poisoning resulting from a pertussis-containing vaccine, where the intent of the poisoning is unknown. This could involve an overdose, incorrect administration, or an idiosyncratic reaction to the vaccine components. The "subsequent encounter" indicates that the patient is receiving follow-up care for this poisoning event after the initial treatment.

Use this code for patients presenting for ongoing management of symptoms related to a pertussis vaccine poisoning, when the circumstances surrounding the poisoning are not yet determined (e.g., accidental, intentional self-harm, assault). This applies after the initial acute phase of treatment has concluded.

• Always assign an additional code for the specific manifestation(s) of the poisoning.
• If the intent of the poisoning is later determined, update the code to reflect the appropriate intent (e.g., accidental, intentional).
• Ensure documentation clearly supports a "subsequent encounter" for the poisoning, not an initial presentation.