Pediatrics · Year 3 · from Pediatrics

Case 1: Atopic Dermatitis with Eczema Herpeticum

Patient Demographics

  • Age: 2-year-old female
  • Sex: Female

Chief Complaint

"Her eczema suddenly got worse and now she has blisters all over."

History of Present Illness

A 2-year-old girl with a history of moderate atopic dermatitis presents with acute worsening of her skin condition over the past 2 days. Her mother notes that the usual red, scaly patches have developed numerous small blisters that look like they have been "punched out." The child has been increasingly irritable, has had fever to 39.5C, and is not eating well. Her 5-year-old sibling had a "cold sore" on the lip last week. The child's eczema has been managed with emollients and intermittent topical hydrocortisone, but her mother reports the eczema was flaring before this new rash developed.

Physical Examination

  • Vital Signs: Temperature 39.2C, HR 130 bpm, RR 26/min
  • General: Irritable, uncomfortable-appearing toddler
  • Skin:
  • Face: Multiple monomorphic, punched-out erosions with hemorrhagic crusting on cheeks and around mouth
  • Arms: Scattered vesicles and erosions with underlying eczematous changes in antecubital fossae
  • Trunk: Clustered vesiculopustules on erythematous base, many with central umbilication
  • Legs: Similar findings in popliteal fossae
  • Lesions appear at the same stage of development (monomorphic)
  • HEENT: No oral lesions visible
  • Lymph nodes: Tender anterior cervical lymphadenopathy

Laboratory Findings

  • Tzanck smear: Multinucleated giant cells present
  • HSV PCR (from vesicle base): Positive for HSV-1
  • CBC: WBC 15,200/uL with lymphocyte predominance

Diagnosis

Eczema herpeticum (Kaposi varicelliform eruption)

Clinical Reasoning

This child with underlying atopic dermatitis has developed eczema herpeticum, a disseminated herpes simplex virus infection occurring in the setting of disrupted skin barrier. The key features are: (1) sudden worsening of eczema with systemic symptoms, (2) monomorphic punched-out erosions (unlike varicella which shows lesions at different stages), (3) clustered vesicles typical of HSV, and (4) exposure to a family member with oral herpes. This is a dermatologic emergency because HSV can disseminate to cause encephalitis, hepatitis, or other organ involvement in these vulnerable patients.

Management

  1. Immediate hospitalization: Required for IV antiviral therapy and monitoring
  2. IV acyclovir: 10-20 mg/kg every 8 hours until new lesions stop appearing and existing lesions are crusting
  3. Transition to oral: Oral acyclovir or valacyclovir to complete 10-14 day course
  4. Ophthalmology consult: Rule out ocular HSV involvement if periorbital lesions present
  5. Wound care: Gentle cleansing, topical antibiotics to prevent secondary bacterial infection
  6. Do NOT use topical corticosteroids: May worsen HSV dissemination
  7. Education: Avoid contact with individuals with active cold sores

Clinical Image

Image Description: A child with eczema herpeticum demonstrating characteristic monomorphic punched-out erosions with hemorrhagic crusting, superimposed on a background of atopic dermatitis.

Source: DermNet NZ URL: https://dermnetnz.org/topics/eczema-herpeticum License: CC BY-NC-ND 3.0 NZ

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