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Difficulty: MediumPediatric Infectious Diseases

Match each clinical vignette describing a neonate with a congenital infection to the most likely causative pathogen.

  • A 2-week-old infant develops copious clear nasal discharge, a desquamating maculopapular rash on the palms and soles, and hepatosplenomegaly. Radiography reveals periostitis of the long bones.Treponema pallidum
  • A neonate is found to have macrocephaly, severe chorioretinitis, and diffuse, scattered intracranial calcifications throughout the brain parenchyma on cranial ultrasound.Toxoplasma gondii
  • A small-for-gestational-age neonate presents with a petechial rash, jaundice, and microcephaly. Head imaging demonstrates calcifications strictly localized to the periventricular areas.Cytomegalovirus (CMV)
  • A newborn is evaluated for a continuous machine-like murmur, absent red reflexes bilaterally, and abnormal auditory brainstem response testing indicating sensorineural hearing loss.Rubella virus
  • A neonate is born prematurely with massive generalized edema, pleural effusions, and ascites. Cord blood analysis demonstrates severe anemia without evidence of structural anomalies.Parvovirus B19

Answer

The correct pairings match each classic neonatal presentation to its specific congenital (TORCH) infection: Syphilis (Treponema pallidum) with snuffles and palmar/plantar rash; Toxoplasmosis with diffuse calcifications and macrocephaly; CMV with periventricular calcifications and microcephaly; Rubella with cataracts, deafness, and a patent ductus arteriosus; and Parvovirus B19 with hydrops fetalis.
Each congenital infection presents with unique, identifying clinical features. Treponema pallidum is characterized by snuffles, periostitis, and a palmar/plantar rash. Toxoplasma gondii causes diffuse intracranial calcifications and hydrocephalus. Cytomegalovirus is identified by periventricular calcifications and microcephaly. Rubella virus classically presents with cataracts, sensorineural hearing loss, and congenital heart defects like a patent ductus arteriosus. Parvovirus B19 targets fetal red blood cells, causing severe anemia that culminates in hydrops fetalis.

Step-by-Step Solution

1
Analyze the first vignette for unique clinical signs.
The presence of copious nasal discharge (snuffles) and a desquamating rash on the palms and soles strongly indicates Treponema pallidum.
These are pathognomonic early signs of congenital syphilis.
2
Differentiate the two vignettes featuring intracranial calcifications.
Diffuse parenchymal calcifications with macrocephaly point to Toxoplasma gondii, while periventricular calcifications with microcephaly point to Cytomegalovirus.
Location of calcifications and head size are the primary differentiating factors for these two congenital infections.
3
Evaluate the vignette with cardiac and ophthalmologic findings.
A continuous machine-like murmur (patent ductus arteriosus) and absent red reflexes (cataracts) alongside hearing loss indicate Rubella virus.
This specific triad is the classic manifestation of congenital rubella syndrome.
4
Assess the final vignette presenting with fluid overload and anemia.
Massive generalized edema, pleural effusions, and severe anemia represent non-immune hydrops fetalis, which is caused by Parvovirus B19.
Parvovirus B19 specifically targets erythroid progenitor cells, leading to severe fetal anemia and subsequent high-output heart failure.

Key Concept

Clinical presentation and differentiation of congenital (TORCH) infections
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Topics

Pediatric Infectious Diseases

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