What is the treatment for eczema herpeticum?

Treatment of Eczema Herpeticum

Eczema herpeticum requires prompt treatment with systemic antiviral therapy, specifically oral acyclovir for mild to moderate cases and intravenous acyclovir for severe or febrile cases. 1

Diagnosis and Clinical Presentation

Eczema herpeticum (EH) is a disseminated herpes simplex virus infection occurring in patients with atopic dermatitis, characterized by:

• Multiple discrete vesicles and erosions on eczematous skin 1
• Umbilicated papules and vesicles with erosions and crusting 2
• Systemic symptoms may include fever and lymphopenia 3

EH should be considered a medical emergency due to potential complications including bacteremia and death if left untreated 2.

Treatment Algorithm

First-Line Treatment:

1. Antiviral Therapy:

   • Mild to moderate cases: Oral acyclovir given early in the course of disease 1
   • Severe or febrile cases: Intravenous acyclovir 1
   • Dosage should be based on the medication's drug profile and patient factors 1

2. Concurrent Management of Bacterial Infection:

   • If secondary bacterial infection is present, add systemic antibiotics 1
   • First choice: Flucloxacillin for Staphylococcus aureus (most common pathogen) 1
   • Alternatives:
     • Phenoxymethylpenicillin if β-hemolytic streptococci are isolated 1
     • Erythromycin for penicillin-allergic patients or resistant cases 1

Treatment Efficacy:

Clinical trials have demonstrated that oral acyclovir is effective for EH with an efficacy rate of 81.3% compared to 42.9% with placebo 4. Before the use of acyclovir, mortality rates for untreated EH ranged from 10-50%, but with proper antiviral therapy, mortality has been dramatically reduced 1.

Special Considerations

Risk Factors for EH:

• Extrinsic atopic dermatitis (AD with elevated IgE levels) 5
• Early onset of AD (especially for recurrent EH) 5, 3
• Severe AD 3

Important Clinical Pearls:

• EH only affects areas with active AD lesions; skin without AD is not affected 5
• Laboratory confirmation may be obtained through viral cultures, molecular diagnostics, or direct fluorescent antibody testing 6, 2
• Recurrent EH may occur and requires vigilant monitoring 5, 6

Pitfalls to Avoid:

• Misdiagnosis as impetigo or primary varicella infection can lead to treatment delays 2
• Delaying antiviral therapy can increase morbidity and length of hospital stay 1
• Thymidine-kinase resistant strains may develop in recurrent cases, requiring alternative antivirals 6

Management of Underlying Atopic Dermatitis

Controlling the underlying AD is crucial for preventing recurrent EH:

• Continue appropriate topical treatments for AD
• For severe, recalcitrant AD requiring systemic treatment, consider non-myelosuppressive immunomodulating agents such as intravenous immunoglobulin or interferon gamma 6

Remember that EH is a dermatologic urgency that requires prompt recognition and treatment to prevent complications and reduce morbidity.