Disseminated herpes or vaccinia in the setting of underlying skin diseases is known as Kaposi’s varicelliform eruption (KVE). Patients typically present with disseminated vesicopustules in the areas of the most severe involvement of their underlying skin disease. We report a case of eczema herpeticum in a woman with a long-standing history of atopic dermatitis (AD). This report also reviews the literature on eczema herpeticum and eczema vaccinatum (EV), summarizes clinical and histopathologic characteristics and treatment, and discusses the recommendations of the Centers for Disease Control and Prevention for smallpox vaccination.
Patients with chronic inflammatory skin diseases, particularly atopic dermatitis (AD), are at risk for dissemination of cutaneous viral infections. Infection is most commonly caused by herpes simplex virus (HSV); however, it also may occur with coxsackievirus or vaccinia. The term Kaposi's varicelliform eruption (KVE) is used synonymously with eczema herpeticum when HSV infects eczematous skin. When KVE occurs in a patient who has received or has come in close contact with someone who has received the smallpox vaccination, it also is referred to as eczema vaccinatum (EV). The pathogenesis of KVE may be related to impaired immune surveillance or simply may represent a mechanical phenomenon secondary to decreased epithelial barrier function. As the threat of bioterrorism with smallpox increases, physicians must address the question of safety when vaccination is considered in individuals with a history of atopy.
Case Report
A 40-year-old woman with long-standing AD presented with a 5-day history of painful vesicles that had started on her right arm and gradually spread to involve the rest of her body. She had been evaluated by a physician and had been placed on prednisone, cephalexin, and triamcinolone without improvement. The patient did not have any preceding history of oral ulcerations or erosions but did report a history of intermittent "cold sores." On examination, her face, chest, arms, abdomen, back, and upper thighs were packed with confluent vesicopapules; some areas were eroded and weeping a yellow serous fluid (Figures 1 through 3). Direct fluorescent antibody (DFA) test yielded positive results of HSV-1 and HSV-2. A diagnosis of eczema herpeticum was made, and treatment with valacyclovir and cephalexin was initiated. Results of a bacterial culture yielded Staphylococcus and Streptococcus species. Biopsy results confirmed cytopathic changes diagnostic of herpesvirus infection with focal keratinocyte necrosis and acantholysis (Figures 4 and 5).
Comment
KVE was first described in 1887 by Moritz Kaposi who was Professor and Chairman of Dermatology at the University of Vienna School of Medicine.1 Kaposi initially thought the condition was secondary to a fungal infection, but the discovery of inclusion bodies histologically suggested a viral etiology.2 The term KVE is now used to describe disseminated herpes simplex, vaccinia, or coxsackievirus in the setting of certain underlying skin diseases.1
Eczema herpeticum is a term often used synonymously with HSV-associated KVE because eczema is the most common underlying skin condition seen in KVE.1 KVE also has been reported to occur in the setting of Darier disease,3,4 cutaneous T-cell lymphoma,5 pityriasis rubra pilaris,6 familial benign chronic pemphigus,7 congenital ichthyosiform erythroderma, seborrheic dermatitis, Wiskott-Aldrich syndrome,8 psoriasis, and lupus erythematosus.9 Additionally, KVE has been reported in patients who have disruption of the epidermal barrier either as a result of irritant contact dermatitis caused by vigorous scrubbing of the face with a facial cleanser,10 following a skin graft,11 in the setting of second-degree burns,12 or after dermabrasion.2 It also has been reported to occur in the setting of multiple myeloma.13
The literature presents conflicting data regarding immunologic defects in response to herpesvirus infection in patients with AD. Although it has been suggested that patients with AD have depressed cell-mediated immunity to HSV, studies have failed to confirm this.14,15 Some authors have postulated that decreased numbers of circulating natural killer cells and a decrease of IL-2 receptors cause patients with atopic eczema to be more susceptible to herpetic infection.15 It may be that the spread of infection is related purely to mechanical factors rather than to immune surveillance.
KVE can present in a primary form or a recurrent form.16 The primary form presents with clusters of umbilicated vesicles and vesicopustules that usually occur in areas where skin has been most affected by the underlying skin disease.17 The lesions gradually spread and are accompanied by systemic symptoms such as fever, malaise, and lymphadenopathy.1 Milder cases may have lesions limited to the head and neck.16 Over time, the vesicles may become hemorrhagic and later develop into erosions that can become secondarily infected.17 More severe cases can result in scarring. Recurrent cases usually are more limited with fewer systemic symptoms.16
Herpetic keratitis is a serious ocular sequela. Fortunately, despite the frequent involvement of vesicopustules on the face, ocular herpetic infection is rare in the setting of KVE.18 One study reported 3 patients with KVE with positive HSV conjunctival culture results but no visible ocular disease.8 KVE can be associated with viremia and involvement of the lungs, liver, brain, and gastrointestinal tract.1 Prior to the availability of antiviral therapy, deaths occurred secondary to rhabdomyolysis and renal failure.18 Bacterial infection of the eroded skin can progress to bacterial sepsis.
Differential Diagnosis and Diagnosis