Infectious Disease · Congenital Infections
The facts most likely to be tested
Congenital varicella syndrome occurs following maternal primary varicella-zoster virus (VZV) infection during the first or second trimester of pregnancy.
Classic cutaneous manifestations include cicatricial skin lesions appearing in a dermatomal distribution.
Affected infants frequently present with limb hypoplasia or atrophy due to damage to the developing peripheral nerves.
Neurological involvement is characterized by microcephaly, cortical atrophy, and seizures.
Ocular findings are highly suggestive and include chorioretinitis, microphthalmia, and cataracts.
The risk of developing congenital varicella syndrome is highest when maternal infection occurs between 8 and 20 weeks gestation.
Diagnosis is confirmed via PCR testing for VZV DNA in amniotic fluid or neonatal tissue, though clinical diagnosis is often based on the classic constellation of findings.
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A 2-week-old male infant is brought to the clinic for evaluation of skin abnormalities noted at birth. The mother reports having had a severe, pruritic, vesicular rash during her 14th week of pregnancy that was diagnosed as chickenpox. Physical examination reveals scarring skin lesions in a dermatomal pattern on the left lower extremity. The infant also exhibits hypoplasia of the left leg and microcephaly. Ocular examination demonstrates chorioretinitis.
What is the most likely diagnosis?
Congenital varicella syndrome
The patient presents with the classic triad of cicatricial skin lesions, limb hypoplasia, and ocular/neurological defects following maternal primary VZV infection in the first trimester, which is pathognomonic for congenital varicella syndrome.
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Etiology / Epidemiology
Occurs via maternal varicella-zoster virus (VZV) infection during the first 20 weeks of gestation.
Clinical Manifestations
Classic triad: cicatricial skin lesions, limb hypoplasia, and neurologic/ocular defects.
Diagnosis
Diagnosis is primarily clinical; PCR of amniotic fluid is the gold standard for prenatal confirmation.
Treatment
Supportive care; Varicella-zoster immune globulin (VZIG) is indicated for exposed neonates, not for established syndrome.
Prognosis
High mortality rate; 30% mortality in the first few months of life for affected infants.
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Epidemiology & Etiology
Congenital varicella syndrome (CVS) results from primary maternal VZV infection, most commonly between 8 and 20 weeks gestation. The risk of fetal transmission is low, estimated at <2% during this window. Maternal immunity (prior vaccination or infection) effectively prevents fetal syndrome.
Pertinent Anatomy
The virus exhibits neurotropism, affecting the dermatomes and developing limb buds. Damage to the central nervous system and peripheral nerves leads to the characteristic structural anomalies observed at birth.
Pathophysiology
VZV causes direct viral damage to fetal tissues during critical organogenesis. The virus induces cicatricial scarring, disrupts bone growth, and causes inflammatory destruction of the developing brain and eyes. This results in permanent, non-progressive structural defects rather than active viral infection at birth.
Clinical Manifestations
Infants present with cicatricial skin lesions in a dermatomal distribution, often appearing as zigzag scarring. Limb hypoplasia and paresis are hallmark findings. Ocular defects include microphthalmia and chorioretinitis. Red flags include seizures, microcephaly, and severe developmental delay.
Diagnosis
Diagnosis is based on the presence of characteristic physical findings in a neonate born to a mother with documented primary VZV infection. PCR of amniotic fluid is the gold standard for prenatal diagnosis. Postnatal diagnosis is confirmed via IgM serology or viral culture from skin lesions.
Treatment
Management is strictly supportive, focusing on physical therapy for limb deformities and seizure control. VZIG is administered to neonates born to mothers who develop varicella 5 days before to 2 days after delivery to prevent neonatal varicella, but it is ineffective for established CVS.
Prognosis
Prognosis is poor, with a 30% mortality rate within the first year of life. Survivors often face significant neurodevelopmental disabilities and chronic orthopedic complications. Long-term monitoring by pediatric neurology and ophthalmology is mandatory.
Differential Diagnosis
Congenital Rubella: presents with cataracts and sensorineural hearing loss
Congenital CMV: presents with periventricular calcifications and petechiae
Congenital Toxoplasmosis: presents with intracranial calcifications and hydrocephalus
Congenital Syphilis: presents with hepatosplenomegaly and Hutchinson teeth
Neonatal Varicella: occurs from maternal infection near delivery, presenting with active vesicles