Anaphylactic reaction due to vaccination, subs encntr

This code describes an anaphylactic reaction that occurred as a severe, systemic allergic response to a vaccination, and the patient is being seen for follow-up care or management of residual effects. Anaphylaxis is a life-threatening condition characterized by rapid onset of symptoms such as hives, angioedema, respiratory distress, and hypotension.

Use this code when documenting subsequent encounters for a patient who previously experienced anaphylaxis due to a vaccine. This includes visits for monitoring, managing lingering symptoms, or addressing complications arising from the initial reaction. It is appropriate for any visit after the initial treatment of the acute anaphylactic episode.

• Always sequence this code after the appropriate external cause code (e.g., Y59.0- for adverse effect of vaccine).
• Ensure documentation clearly specifies "subsequent encounter" to justify the use of the "D" seventh character.
• Do not use for the initial treatment of the acute anaphylactic reaction; for that, use the "A" (initial encounter) seventh character.