What is the treatment for Herpes herpeticum, especially in patients with a history of recurrent Herpes simplex infections?

Treatment of Eczema Herpeticum

Eczema herpeticum is a dermatologic emergency requiring immediate systemic antiviral therapy with intravenous acyclovir, particularly in severe cases or immunocompromised patients, as this condition historically carried a 10-50% mortality rate before antiviral therapy became available. 1

Immediate Treatment Protocol

First-Line Systemic Antiviral Therapy

• Intravenous acyclovir is the treatment of choice for eczema herpeticum, especially in severe presentations, immunocompromised patients, or those requiring hospitalization. 1

• IV acyclovir dosing: 5-10 mg/kg every 8 hours for 5-7 days or until clinical resolution is attained. 1

• Earlier initiation of acyclovir directly correlates with shorter hospital stays and better outcomes—timing is critical. 1

• A retrospective review of 1,331 children from 42 tertiary care pediatric hospitals demonstrated zero mortality when patients received systemic antiviral therapy, compared to the historical 10-50% mortality rate without treatment. 1

Oral Antiviral Options for Milder Cases

For less severe presentations in immunocompetent patients who can tolerate oral therapy:

• Acyclovir 400 mg orally 5 times daily until clinical resolution. 1

• Valacyclovir 1 gram orally twice daily for 7-10 days (superior bioavailability, less frequent dosing). 2

• Famciclovir 250 mg orally three times daily for 7-10 days as an alternative. 2

Critical Clinical Considerations

Why Systemic Therapy is Mandatory

• Topical acyclovir is substantially less effective than systemic therapy and should NOT be used as primary treatment for eczema herpeticum. 1, 2

• Eczema herpeticum represents widespread HSV infection in compromised skin barrier (atopic dermatitis), requiring systemic viral suppression that topical agents cannot achieve. 1, 3

• The infection can rapidly progress to life-threatening disseminated disease, particularly in patients with extensive atopic dermatitis. 4

Patients with Recurrent Herpes Simplex Infections

For patients with a history of recurrent HSV who develop eczema herpeticum:

• Treat the acute eczema herpeticum episode aggressively with systemic antivirals as outlined above—do not rely on their previous recurrent infection treatment regimens. 1

• After resolution, consider long-term suppressive antiviral prophylaxis to prevent future episodes of eczema herpeticum, particularly if recurrences are frequent (≥6 episodes/year). 1, 2

• Suppressive therapy regimens:

  • Acyclovir 400 mg orally twice daily, or 1
  • Valacyclovir 500 mg once daily, or 2
  • Famciclovir 250 mg twice daily 2

• Suppressive therapy reduces HSV recurrence frequency by at least 75% in patients with frequent recurrences. 1, 2

Monitoring and Treatment Duration

• Continue treatment until all lesions have completely crusted and clinical resolution is achieved—do not stop at an arbitrary 7-day mark if active lesions persist. 1

• For IV acyclovir, monitor renal function at initiation and once or twice weekly during treatment, with dose adjustments for renal impairment. 5

• If lesions fail to improve within 7-10 days despite appropriate therapy, suspect acyclovir resistance and obtain viral culture with susceptibility testing. 5, 2

Acyclovir-Resistant Cases

• For confirmed acyclovir-resistant HSV, switch to IV foscarnet 40 mg/kg every 8 hours until clinical resolution. 5, 2

• Resistance is rare in immunocompetent patients (<0.5%) but occurs more frequently in immunocompromised patients (7% for acyclovir). 1

Adjunctive Management

Concurrent Atopic Dermatitis Treatment

• Systemic antibiotics should be added if there is clinical evidence of secondary bacterial infection (common with S. aureus superinfection in atopic dermatitis). 1

• Continue appropriate topical corticosteroids for underlying atopic dermatitis alongside antiviral therapy—do not discontinue AD treatment during acute eczema herpeticum. 1

• However, avoid initiating or escalating systemic immunosuppression until the HSV infection is controlled. 1

Common Pitfalls to Avoid

• Never use topical acyclovir alone—it cannot address the systemic viral replication occurring in eczema herpeticum. 1, 2

• Do not delay systemic antiviral therapy while waiting for viral culture confirmation—clinical diagnosis should prompt immediate treatment given the historical mortality risk. 1

• Do not use valacyclovir 8 grams per day in immunocompromised patients due to risk of hemolytic uremic syndrome/thrombotic thrombocytopenic purpura. 2

• Do not confuse eczema herpeticum with simple recurrent herpes labialis—the former requires aggressive systemic therapy while the latter may be managed with shorter courses or even topical therapy in mild cases. 1, 3

Special Populations

Immunocompromised Patients

• Immunocompromised patients require IV acyclovir and may need prolonged treatment courses beyond 7-10 days. 1

• Consider temporary reduction of immunosuppressive medications if clinically feasible during acute infection. 5, 6

Pediatric Patients

• The same treatment principles apply to children—systemic acyclovir is safe and effective in pediatric populations with eczema herpeticum. 1

• Dosing remains weight-based: 5-10 mg/kg IV every 8 hours. 1

Pregnant Patients

• Acyclovir is considered safe during pregnancy and should not be withheld for eczema herpeticum given the serious maternal and fetal risks of untreated infection. 1