InfectionEmergencyICD-10 B00.0
Eczema herpeticum & cutaneous HSV
Kaposi varicelliform eruption · disseminated HSV · widespread herpes simplex
Eczema herpeticum (Kaposi varicelliform eruption) is a disseminated cutaneous herpes simplex virus (HSV-1 > HSV-2) infection superimposed on a disrupted skin barrier — most often atopic eczema, but also Darier disease, pemphigus, burn injury, pityriasis rubra pilaris, ichthyosis, mycosis fungoides, post-Mohs / large-defect reconstruction, and ICI-related dermatitis. It is a dermatological emergency requiring early antiviral therapy. Recognition matters in skin-oncology because both ICI-induced eczema and post-surgical denuded skin are predisposing settings.
CurrentLast reviewed 16 May 2026
Context and risk factors
- Most common predisposition: atopic eczema.
- Other underlying conditions:
- Darier disease, Hailey-Hailey, pemphigus, bullous pemphigoid, pityriasis rubra pilaris, ichthyosis.
- Burns, large surgical defects, post-grafting wounds.
- Mycosis fungoides, cutaneous T-cell lymphoma.
- ICI-related dermatitis, eczema flares on EGFRi / BRAFi.
- Immunosuppression — transplant, HIV.
- HSV-1 > HSV-2; reactivation or primary infection.
Clinical features
- Abrupt onset crops of monomorphic 2-3 mm umbilicated vesicopustules on existing dermatosis, often face / neck / trunk.
- Punched-out erosions and haemorrhagic crusts after vesicle rupture.
- Pain rather than itch may predominate.
- Systemic features: fever, malaise, lymphadenopathy, sometimes sepsis.
- Severe forms: keratoconjunctivitis, encephalitis, hepatitis, disseminated intravascular coagulation.
- Differentiate from typical eczema flare (vesicles + punched-out erosions, not background lichenification only).
Investigations
- HSV PCR from vesicle / erosion swab — sensitive and specific; results within hours.
- Tzanck smear (multinucleated giant cells; doesn't distinguish HSV vs VZV).
- Bacterial swab — secondary S. aureus infection common; eczema herpeticum + impetigo coexistence frequent.
- Bloods if systemic features: FBC, LFT, U&E, CRP, blood cultures; consider HIV.
- Ophthalmology review if periocular involvement.
Differentials
- Bullous impetigo / staphylococcal scalded skin — staphylococcal exotoxin; large fragile bullae.
- Varicella / disseminated zoster — pleomorphic vs monomorphic vesicles.
- Hand-foot-and-mouth disease (Coxsackie).
- Smallpox / monkeypox in atypical / travel-related cases.
- Disseminated CMV / EBV in immunosuppressed.
- SJS/TEN — drug history; mucosal involvement.
- Eczema flare with crusting — no punched-out erosions or vesicles.
Management
- Empirical antiviral while awaiting PCR — do not delay:
- Aciclovir 400-800 mg PO 5× daily for 5-7 days.
- Valaciclovir 1 g PO BD until lesions heal (typically 10–14 days).
- IV aciclovir 5-10 mg/kg TDS in severe / systemic / paediatric / immunosuppressed / ocular involvement / no oral tolerance.
- Hold topical calcineurin inhibitors and tapering of high-potency topical steroids until infection controlled.
- Bland emollients; eczema management resumes once infection controlled.
- Treat coexistent bacterial superinfection (flucloxacillin / co-amoxiclav).
- Admit if systemic features, ocular involvement, immunosuppression, paediatric, or significant body-surface area.
- Education re recognition (early antiviral course at home for recurrent disease in atopic patients).
- Long-term suppressive aciclovir (400 mg BD) in recurrent disease.
- Skin-oncology specifics:
- ICI dermatitis with eczematous appearance: do not start TCI in suspected EH; PCR first.
- Post-Mohs / post-graft denuded skin: empirical antiviral if widespread vesicles; multidisciplinary discussion.
References
- Wollenberg A et al. Eczema herpeticum and other dermatoses complicated by herpes simplex virus infection. J Allergy Clin Immunol. 2003;112:667-674.
- Aronson PL et al. Risk factors for severe disease in eczema herpeticum. J Pediatr. 2014;164:1131-1136.
- Beck LA, Boguniewicz M, Hata T, et al. Phenotype of atopic dermatitis subjects with a history of eczema herpeticum. J Allergy Clin Immunol. 2009;124:260-269.
- NICE CKS. Atopic eczema — herpes simplex infection. London: NICE; accessed 18 May 2026.
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