What are the indications for antibiotics (abx) in eczema herpeticum?

Indications for Antibiotics in Eczema Herpeticum

Antibiotics are only indicated in eczema herpeticum when there is clinical evidence of secondary bacterial infection, not for the primary viral infection itself. 1

Understanding Eczema Herpeticum

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

• Multiple discrete vesicles and erosions on areas of pre-existing eczema 1
• Potential for significant morbidity and mortality if left untreated 1, 2
• Primary treatment is systemic antiviral therapy, not antibiotics 1

Specific Indications for Antibiotics

Antibiotics should be used in eczema herpeticum only when:

• Overt secondary bacterial infection is clinically evident 1
• Signs of bacterial superinfection are present, such as:
  • Purulent exudate or pustules 1
  • Crusting that appears infected rather than simply part of the dermatitis 1
  • Systemic signs of infection (fever, elevated inflammatory markers) 1

Antibiotic Selection for Secondary Bacterial Infection

When secondary bacterial infection is confirmed:

• Flucloxacillin is typically the first-line antibiotic for treating Staphylococcus aureus, the most common pathogen 1
• Phenoxymethylpenicillin should be used if Group A beta-hemolytic streptococci are isolated 1
• Erythromycin is appropriate for patients with penicillin allergy or when resistance to flucloxacillin is identified 1
• Skin culture with bacterial antibiotic susceptibility testing may be necessary for recurrent or non-responsive infections 1

Important Considerations

• Antibiotics should be administered alongside standard atopic dermatitis treatment, including topical steroids 1
• Systemic antiviral therapy (acyclovir) is the mainstay of treatment for the primary HSV infection in eczema herpeticum 1
• Early initiation of antiviral therapy is crucial and correlates with reduced length of hospital stay and better outcomes 1
• In ill, febrile patients, intravenous acyclovir should be given rather than oral therapy 1

Common Pitfalls to Avoid

• Using antibiotics for colonization without clinical infection: S. aureus colonizes >90% of atopic dermatitis patients, but antibiotics should not be used unless there is clear evidence of infection 1, 3
• Delaying antiviral therapy: This can lead to increased morbidity and longer hospital stays 1
• Missing secondary bacterial infection: Patients with eczema herpeticum are at increased risk for secondary bacterial infections, particularly with S. aureus 2, 4
• Failing to recognize eczema herpeticum: Early recognition is critical as untreated cases can progress to shock, sepsis, and death 2

Evidence Quality

The recommendations are based on clinical guidelines from reputable dermatology organizations, with the American Academy of Dermatology guidelines from 2014 1 representing the most recent comprehensive guidance on this topic. These guidelines clearly state that systemic antibiotics should be reserved for cases with clinical evidence of bacterial infection, while all cases of eczema herpeticum require systemic antiviral therapy.