What is the recommended management of herpes zoster in a pregnant woman?

Management of Herpes Zoster (Shingles) in Pregnancy

Oral acyclovir is the recommended first-line treatment for herpes zoster in pregnant women, given at 800 mg five times daily, and should be initiated as soon as possible after rash onset. 1

Safety Profile in Pregnancy

• Acyclovir is classified as FDA Category B in pregnancy and has the most extensive safety data of any antiviral agent used during pregnancy 2, 1
• A registry of 596 infants exposed to acyclovir during the first trimester showed no increased rate of birth defects compared to the general population (2.3% vs. 3.2%), with no specific pattern of defects linked to the drug 1
• Acyclovir is the antiviral drug with the most reported experience in pregnancy and appears to be safe, making it the first choice for therapy of herpes zoster infections in pregnancy 2

Treatment Protocol

Oral acyclovir 800 mg five times daily should be started within 24 hours of rash onset for maximum effectiveness 1, 3, 4

• Treatment is most effective when initiated within 24 hours of rash appearance, as this timing reduces severity of symptoms and accelerates healing 1, 3
• For severe disease or complications (such as disseminated infection, encephalitis, or pneumonitis), intravenous acyclovir at 10 mg/kg every 8 hours is indicated 2, 4
• Treatment should be continued for 7-10 days, or until all lesions have crusted 4, 5

Key Distinctions: Herpes Zoster vs. Varicella in Pregnancy

Maternal herpes zoster during pregnancy does NOT cause congenital varicella syndrome, unlike maternal varicella (chickenpox) infection 1

• Herpes zoster represents reactivation of latent varicella-zoster virus and does not result in viremia that can cross the placenta 6
• Multiple studies of perinatal maternal herpes zoster infection suggest no intrauterine transmission to the fetus 6
• The primary concern with herpes zoster in pregnancy is maternal comfort and prevention of complications, not fetal risk 6

Transmission Precautions

• Herpes zoster is significantly less contagious than chickenpox—approximately 20% as transmissible—and spreads only through direct contact with fluid from active vesicles 7
• The pregnant woman with herpes zoster should avoid contact with other susceptible pregnant women, neonates, and immunocompromised individuals until all lesions are fully crusted 7
• Lesions should be kept covered, and the patient should maintain good hand hygiene to prevent transmission 7
• The contagious period extends from 1-2 days before rash onset until all lesions have dried and crusted, typically 4-7 days after rash onset 7

Critical Pitfalls to Avoid

• Do not delay treatment waiting for laboratory confirmation—herpes zoster is a clinical diagnosis, and antiviral therapy must be started within 24 hours of rash onset for optimal benefit 1, 3
• Do not confuse herpes zoster with varicella exposure management—pregnant women with herpes zoster do NOT require varicella-zoster immune globulin (VZIG), as this is only indicated for susceptible pregnant women exposed to varicella or herpes zoster 2, 1
• Do not assume the fetus is at risk for congenital varicella syndrome—this complication only occurs with maternal varicella infection in the first or second trimester, not with herpes zoster 1, 6
• Do not use intravenous acyclovir routinely—reserve IV therapy for severe disease with complications or risk factors, such as disseminated infection, immunocompromise, or involvement of the ophthalmic division of the trigeminal nerve 2, 4

Monitoring and Follow-up

• Monitor for signs of dissemination (new lesions appearing outside the primary dermatome) or complications such as pneumonitis, encephalitis, or hepatitis 2
• Ensure adequate hydration during treatment, particularly if using higher doses of acyclovir, and monitor renal function if there is pre-existing renal impairment 4
• Reassure the patient that herpes zoster in pregnancy does not pose a risk to the fetus and that treatment is primarily for maternal benefit 6