Eczema herpeticum

OVERVIEW

• Disseminated viral infection characterized by fever, lymphadenopathy, and acute eruption of painful, monomorphic clustered vesicles
• Most often seen as a complication of atopic dermatitis/eczema
• Most cases due to HSV-1 or HSV-2
• Eczema herpeticum is one of the few dermatological emergencies

CLINICAL FEATURES

• Fever
• Lymphadenopathy
• Malaise
• Skin lesions:
  • Clusters of monomorphic itchy and painful blisters, most often on face and neck
  • New patches form and spread over 7-10 days
  • May be filled with clear yellow fluid or thick purulent material
  • Often blood-stained
  • Older blisters crust over and form erosions
  • Lesions heal over 3-6 weeks

INVESTIGATIONS

• Blister scrapings for viral culture and/or PCR
• Bacterial swab for MCS as eczema herpeticum can resemble impetigo, and may be complicated by secondary bacterial infection

MANAGEMENT

• Oral acyclovir 400-800mg 5 times daily; or valaciclovir 1g BD, for 10-14 days or until lesions heal
• Secondary bacterial skin infection requires antibiotic therapy
• Topical steroids are not recommended
• Ophthalmology review is required if eyelid or eye involvement is suspected

COMPLICATIONS

• Secondary bacterial infection with staphylococci or streptococci causing impetigo and cellulitis
• Severe cases may cause multi-organ involvement, including eyes, brain, lung and liver
• Mortality is rare