Contagious illness caused by the varicella zoster virus; can impact the foetus if mother catches it for the first time in pregnancy

Clinical features (mother)

• Fever
• Malaise
• Vesicular rash

Investigations

• Usually obvious on clinical grounds
• Confirmation can be obtained by scraping a lesion and using immunohistochemical staining or PCR

Management

• When the pregnant woman has previously had chickenpox, they are safe
• When they are not sure about their immunity, test the VZV IgG levels
• When they are not immune, they can be treated with IV varicella immunoglobulins as prophylaxis against developing chickenpox; this should be given within ten days of exposure
• Supportive treatment
• Acyclovir should be considered if 20+ weeks
• Severe chicken pox:
  • Hospitalize, IV acyclovir
  • Aim to prevent complications - hepatitis, encephalitis, pneumonia

Complications

• It is dangerous in pregnancy because it can lead to:
  • More severe cases in the mother e.g. varicella pneumonitits, hepatitis, or encephalitis
  • Fetal varicella syndrome
  • Severe neonatal varicella infection
• The typical features of congenital varicella syndrome include:
  • Fetal growth restriction
  • Microcephaly, hydrocephalus and learning disability
  • Scars and significant skin changes located in specific dermatomes
  • Limb hypoplasia (underdeveloped limbs)
  • Cataracts and inflammation in the eye (chorioretinitis)