Congenital varicella syndrome

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Congenital Varicella Syndrome is a rare fetal disorder caused by intrauterine infection with varicella-zoster virus (VZV) during early pregnancy, resulting in a spectrum of cutaneous, neurological, ocular, and musculoskeletal anomalies.

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Epidemiology

Incidence: ~0.9–2% if maternal varicella occurs in first 20 weeks of pregnancy.
Risk highest if maternal infection between 13–20 weeks.
Rare after 20 weeks gestation; almost no cases reported if infection occurs after 28 weeks.

Pathogenesis

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Risk period for CVS: Before 20 weeks gestation, especially weeks 13–20.

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Maternal primary varicella infection → transplacental transmission of VZV → fetal infection.
Virus infects developing tissues → inflammation, necrosis, and scarring.
Persistent viral infection may impair organogenesis and cause segmental tissue loss.

Clinical Features

Classic tetrad (may not all be present):

Dermatomal skin scars + ipsilateral limb hypoplasia + CNS defects + ocular anomalies

Domain	Manifestations
1. Skin	Cicatricial skin scarring in a dermatomal distribution.
2. Neurological	• Cortical atrophy, microcephaly.
• Intellectual disability.
• Seizures.
• Segmental motor/sensory deficits.
• Limb paresis from spinal cord damage.
3. Ocular	• Chorioretinitis
• Microphthalmia.
• Cataracts.
• Optic nerve atrophy.
4. Limb hypoplasia	Often ipsilateral to skin lesions; due to denervation and ischemia.

Other possible findings:

Gastrointestinal or genitourinary malformations.
Growth restriction.