Postimmunization acute necrotizing hemorrhagic encephalopathy
ICD-10 G04.32 is a billable code used to indicate a diagnosis of postimmunization acute necrotizing hemorrhagic encephalopathy.
Postimmunization acute necrotizing hemorrhagic encephalopathy (PAHNE) is a rare but severe neurological condition that can occur following vaccination. It is characterized by rapid onset of neurological symptoms, including seizures, altered mental status, and focal neurological deficits. The condition is associated with necrotizing lesions in the brain, leading to hemorrhagic changes, which can be detected through neuroimaging studies such as MRI. The pathophysiology is thought to involve an autoimmune response triggered by the vaccine, resulting in inflammation and damage to the central nervous system (CNS). Clinically, patients may present with symptoms similar to those of viral encephalitis, but the acute nature and association with recent immunization are key distinguishing factors. Diagnosis is often supported by the exclusion of other infectious causes of encephalopathy, and timely recognition is crucial for management, which may include corticosteroids and supportive care. Given its rarity, awareness among healthcare providers is essential for early identification and intervention.
Detailed neurological examination findings, imaging results, and vaccination history.
Patients presenting with acute neurological symptoms following vaccination.
Ensure clear documentation of the timeline between vaccination and symptom onset.
History of vaccination, exclusion of other infectious causes, and laboratory results.
Patients with encephalopathy where vaccination history is relevant.
Consideration of differential diagnoses and thorough documentation of clinical reasoning.
Used to evaluate for hemorrhagic changes in the brain.
Document indications for imaging and findings.
Neurology may require additional imaging studies.
Common symptoms include seizures, altered mental status, headache, and focal neurological deficits, typically occurring shortly after vaccination.
