Most common extra-cutaneous manifestation of chicken pox in children is:
CNS involvement
Varicella pneumonia
Congenital varicella
Reye syndrome
The most common extracutaneous site of involvement in chicken pox in children is the CNS. CSF contains lymphocytes and elevated levels of protein. CNS involvement is a benign complication of VZV infection in children and generally does not require hospitalization. Aseptic meningitis, encephalitis, transverse myelitis, and Guillain-Barre syndrome can also occur.
viral infection