Eczema Herpeticum

Background

• Eczema herpeticum is a cutaneous vesicular eruption caused by herpes simplex type 1 or type 2 virus that occurs in patients with an underlying skin disorder, most commonly atopic dermatitis.

Evaluation

• Eczema herpeticum is characterized by monomorphic papulovesicular lesions, which are often eroded ("punched-out").
• Lesions occur on areas affected by atopic dermatitis or another skin disorder and can spread to unaffected skin.
• Systemic symptoms such as fever, lymphadenopathy, or keratoconjunctivitis can be present, and suggest more severe infection.
• Viral culture confirms the diagnosis, but may take up to 48 hours for results, and has low sensitivity. Tzanck smear, polymerase chain reaction, or direct fluorescent antibody testing may be helpful to support a clinical diagnosis.

Management

• Start acyclovir for known or high suspicion of eczema herpeticum.
  • For severe infection in adults or children, acyclovir 5-10 mg/kg IV 3 times daily for 5-7 days, and for infants, acyclovir 10-20 mg/kg IV 3 times daily.
  • For mild disease, options include:
    • acyclovir 400 mg orally 5 times daily in adults and adolescents, and acyclovir 25-60 mg/kg orally daily divided into 3-5 doses in children ≤ 12 years old
    • valacyclovir 500 mg orally 3 times daily in adolescents and adults
    • famciclovir 500 mg orally twice daily in adolescents and adults
• Consider prophylactic antibiotics for secondary bacterial infection, with coverage of Staphylococcus aureus as this organism frequently colonizes patients with atopic dermatitis.
• For patients with severe recurrent eczema herpeticum, consider prophylactic antiviral therapy.