What is the recommended treatment for an infant diagnosed with shingles (herpes zoster)?

Treatment of Shingles in Infants

Infants diagnosed with shingles should be treated with oral acyclovir at 20 mg/kg body weight (maximum 400 mg/dose) three times daily for 5-10 days, ideally started within 24 hours of rash onset. 1

First-Line Antiviral Treatment

• Oral acyclovir is the primary treatment recommended by the CDC for shingles in immunocompetent children, including infants 1
• The standard dosing is acyclovir 20 mg/kg body weight (maximum 400 mg/dose) orally 3 times daily for 5-10 days 1
• Treatment must be initiated within 24 hours of rash onset to maximize effectiveness 1, 2
• Early antiviral therapy shortens viral shedding, accelerates healing by 1-2 days, and reduces the intensity and duration of acute pain 3

When to Escalate to Intravenous Therapy

For severe cases or immunocompromised infants, intravenous acyclovir is necessary:

• IV acyclovir dosing: 10 mg/kg body weight every 8 hours 1, 2
• This route is indicated for disseminated disease, visceral involvement, or any immunocompromised state 1, 4
• Immunocompromised infants are at high risk for severe complications including viral pneumonia, encephalitis, and hepatitis 4

Critical Considerations for Infants

Shingles in infancy warrants special attention:

• Infants who acquired chickenpox during their first year of life have an increased risk of developing shingles 5
• While shingles is rare in children overall, when it occurs in infants, the diagnosis is primarily clinical based on the characteristic unilateral dermatomal vesicular rash 6
• If history and physical examination are normal, laboratory testing for occult immunodeficiency or malignancy is not necessary 6
• However, nine out of 25 pediatric cases in one series were immunocompromised, highlighting the importance of considering underlying conditions 6

Adjunctive Management

Beyond antivirals, supportive care includes:

• Antiseptic measures to prevent secondary bacterial infection 6
• Analgesics for pain control as needed 6
• Antibiotics only if secondary bacterial infection develops 6

Prevention in Susceptible Infants

For infants exposed to varicella-zoster virus who have never had chickenpox:

• Varicella zoster immune globulin (VZIG) should be administered within 96 hours of exposure (ideally within 48 hours) 5, 1
• VZIG dosing: 1 vial (1.25 mL) per 10 kg body weight intramuscularly (maximum 5 vials) 5
• If VZIG is unavailable, consider a 7-day course of oral acyclovir started 7-10 days after exposure 2

Common Pitfalls to Avoid

• Do not delay treatment initiation, especially in high-risk infants 2
• Do not withhold antiviral therapy while awaiting laboratory confirmation—the diagnosis is clinical 6
• Do not assume a benign course in immunocompromised infants, as they require aggressive IV treatment 1, 4
• Chronic suppressive therapy is not needed after lesions resolve 2

Prognosis

• Immunocompetent infants with shingles typically have a favorable outcome without sequelae when treated appropriately 6
• All 25 pediatric patients in a recent case series had complete resolution with no long-term complications 6