| Pathogenesis | • Vertical transmission ◦ Intrauterine, perinatal, postnatal • typically occurs during delivery by a mother with active genital lesions • Also be contracted in utero (rare and often fatal) • Postnatally through direct exposure to a contact's active lesion (eg, cold sore). | | --- | --- | | Clinical findings | • Skin-eye-mouth ◦ Mucocutaneous vesicles ◦ Keratoconjunctivitis • CNS ◦ Seizures, fever, lethargy ◦ Temporal lobe hemorrhage/edema • Disseminated ◦ Sepsis, hepatitis, pneumonia | | Diagnosis | • Viral surface cultures • HSV PCR (blood, cerebrospinal fluid) | | Treatment | • Acyclovir |
Characteristic vesicles on an erythematous base are prominent in skin-eye-mouth disease; however, cutaneous findings may be absent in CNS and disseminated disease. CNS disease, as seen in this patient, typically presents in the second or third week of life with signs of encephalitis, including seizure, lethargy, and poor feeding. A full fontanel is suggestive of increased intracranial pressure.
Viral transmission through the olfactory bulb to the temporal lobe results in temporal lobe hemorrhage and edema, as seen on this patient's imaging. Lumbar puncture typically shows elevated white blood cells and normal to low glucose. The presence of red blood cells in the cerebrospinal fluid (CSF) is less common in neonates with HSV encephalitis than in older children and in adults. Empiric acyclovir is initiated while awaiting confirmatory results of HSV PCR testing of the CSF.
“ Brain imaging reveals patchy areas of increased attenuation in the cerebral cortex and edema and hemorrhage in the left temporal lobe and brainstem”
(Choices A and E) Cytomegalovirus (CMV) and Toxoplasma gondii can cause neonatal seizures, but intracranial calcifications are seen on neuroimaging in both conditions. In addition, symptomatic congenital toxoplasmosis and CMV infection also typically present with other findings such as jaundice, hepatosplenomegaly, and chorioretinitis.
(Choices B and D) Neonatal bacterial meningitis due to group B Streptococcus and Listeria monocytogenes can cause fever and seizure. Imaging findings may include cerebral edema, hydrocephalus, and abscess but not temporal lobe hemorrhage, which is highly specific for HSV.