2019 ICD-10-CM Diagnosis Code B01.1

Varicella encephalitis, myelitis and encephalomyelitis

    2016 2017 2018 2019 Non-Billable/Non-Specific Code
  • B01.1 should not be used for reimbursement purposes as there are multiple codes below it that contain a greater level of detail.
  • The 2019 edition of ICD-10-CM B01.1 became effective on October 1, 2018.
  • This is the American ICD-10-CM version of B01.1 - other international versions of ICD-10 B01.1 may differ.
Applicable To
  • Postchickenpox encephalitis, myelitis and encephalomyelitis
The following code(s) above B01.1 contain annotation back-references
Annotation Back-References
In this context, annotation back-references refer to codes that contain:
  • Applicable To annotations, or
  • Code Also annotations, or
  • Code First annotations, or
  • Excludes1 annotations, or
  • Excludes2 annotations, or
  • Includes annotations, or
  • Note annotations, or
  • Use Additional annotations
that may be applicable to B01.1:
  • A00-B99
    2019 ICD-10-CM Range A00-B99

    Certain infectious and parasitic diseases

    Includes
    • diseases generally recognized as communicable or transmissible
    Type 1 Excludes
    • certain localized infections - see body system-related chapters
    Type 2 Excludes
    • carrier or suspected carrier of infectious disease (Z22.-)
    • infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
    • infectious and parasitic diseases specific to the perinatal period (P35-P39)
    • influenza and other acute respiratory infections (J00-J22)
    Use Additional
    • code to identify resistance to antimicrobial drugs (Z16.-)
    Certain infectious and parasitic diseases
Clinical Information
  • Inflammation of brain tissue caused by infection with the varicella-zoster virus (herpesvirus 3, human). This condition is associated with immunocompromised states, including the acquired immunodeficiency syndrome. Pathologically, the virus tends to induce a vasculopathy and infect oligodendrocytes and ependymal cells, leading to cerebral infarction, multifocal regions of demyelination, and periventricular necrosis. Manifestations of varicella encephalitis usually occur 5-7 days after onset of herpes zoster and include headache; vomiting; lethargy; focal neurologic deficits; fever; and coma. (from Joynt, Clinical Neurology, 1996, ch 26, pp29-32; hum pathol 1996 sep;27(9):927-38)
Code History
  • 2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
  • 2017 (effective 10/1/2016): No change
  • 2018 (effective 10/1/2017): No change
  • 2019 (effective 10/1/2018): No change
Code annotations containing back-references to B01.1:
  • Type 1 Excludes: G05
    , G04.01
    ICD-10-CM Diagnosis Code G05

    Encephalitis, myelitis and encephalomyelitis in diseases classified elsewhere

      2016 2017 2018 2019 Non-Billable/Non-Specific Code
    Code First
    • underlying disease, such as:
    • human immunodeficiency virus [HIV] disease (B20)
    • poliovirus (A80.-)
    • suppurative otitis media (H66.01-H66.4)
    • trichinellosis (B75)
    Type 1 Excludes
    • adenoviral encephalitis, myelitis and encephalomyelitis (A85.1)
    • congenital toxoplasmosis encephalitis, myelitis and encephalomyelitis (P37.1)
    • cytomegaloviral encephalitis, myelitis and encephalomyelitis (B25.8)
    • encephalitis, myelitis and encephalomyelitis (in) measles (B05.0)
    • encephalitis, myelitis and encephalomyelitis (in) systemic lupus erythematosus (M32.19)
    • enteroviral encephalitis, myelitis and encephalomyelitis (A85.0)
    • eosinophilic meningoencephalitis (B83.2)
    • herpesviral [herpes simplex] encephalitis, myelitis and encephalomyelitis (B00.4)
    • listerial encephalitis, myelitis and encephalomyelitis (A32.12)
    • meningococcal encephalitis, myelitis and encephalomyelitis (A39.81)
    • mumps encephalitis, myelitis and encephalomyelitis (B26.2)
    • postchickenpox encephalitis, myelitis and encephalomyelitis (B01.1-)
    • rubella encephalitis, myelitis and encephalomyelitis (B06.01)
    • toxoplasmosis encephalitis, myelitis and encephalomyelitis (B58.2)
    • zoster encephalitis, myelitis and encephalomyelitis (B02.0)
    ICD-10-CM Diagnosis Code G04.01

    Postinfectious acute disseminated encephalitis and encephalomyelitis (postinfectious ADEM)

      2016 2017 2018 2019 Billable/Specific Code
    Type 1 Excludes
    • post chickenpox encephalitis (B01.1)
    • post measles encephalitis (B05.0)
    • post measles myelitis (B05.1)
ICD-10-CM Codes Adjacent To B01.1
B00.53 Herpesviral conjunctivitis
B00.59 Other herpesviral disease of eye
B00.7 Disseminated herpesviral disease
B00.8 Other forms of herpesviral infections
B00.81 Herpesviral hepatitis
B00.82 Herpes simplex myelitis
B00.89 Other herpesviral infection
B00.9 Herpesviral infection, unspecified
B01 Varicella [chickenpox]
B01.0 Varicella meningitis
B01.1 Varicella encephalitis, myelitis and encephalomyelitis
B01.11 Varicella encephalitis and encephalomyelitis
B01.12 Varicella myelitis
B01.2 Varicella pneumonia
B01.8 Varicella with other complications
B01.81 Varicella keratitis
B01.89 Other varicella complications
B01.9 Varicella without complication
B02 Zoster [herpes zoster]
B02.0 Zoster encephalitis
B02.1 Zoster meningitis

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.