This patient’s presentation of macrocephaly, hypotonia, jaundice, purpuric rash, chorioretinitis, and diffusely scattered calcifications is consistent with congenital toxoplasmosis caused by the organism Toxoplasma Gondii.
Congenital rubella infection is associated with cataracts, congenital heart defects, and less commonly with jaundice and chorioretinitis. While congenital cytomegalovirus infection is associated with parenchymal calcifications, they are often in the periventricular and basal ganglia regions. Too, CMV usually presents with sensorineural deafness, hepatosplenomegaly, and microcephaly, which is not seen in this case. Congenital syphilis infection is caused by Treponema pallidum and presents at birth with bloody nasal discharge (“snuffles”), long bone deformities, keratitis, and frontal bossing. Infection with herpes simplex virus may manifest with temporal lobe lesions on MRI, with sparing of the basal ganglia.