Review Question - QID 105446

This infant with a history of eczema, fever, irritability, malaise, and a disseminated monomorphic vesicular rash most likely has eczema herpeticum, for which the treatment is acyclovir.

Eczema herpeticum is a potentially life-threatening rash caused by infection with herpes simplex virus (HSV) in the setting of an impaired skin barrier (such as eczema). It classically presents as a red, vesicular rash. There are often "punched out" erosions and associated crusting that give the rash its characteristic appearance. Although it can occur in any age group, this condition is particularly life-threatening in infants, who already have a relatively weak immune system. Complications include herpes keratoconjunctivitis, herpes encephalitis, and viremia. Acyclovir treats the infection and prevents complications. While mild cases may be managed with oral acyclovir, more severe cases or those with an immunocompromised state require intravenous therapy. Patients will often require hospital admission with additional supportive care.

Xiao et. al review the clinical manifestations, diagnosis and management of eczema herpeticum. They note the association of the disease with atopic dermatitis. They recommend treatment with acyclovir and state that while mild cases may be managed with oral acyclovir, moderate to severe cases require intravenous acyclovir.

Figure A shows an infant with a red, vesicular monomorphic rash across the face, with associated erosions and crusting, consistent with eczema herpeticum.

Incorrect answers:
Answer 1: Cefazolin may be used to treat cellulitis. Cellulitis is less common in this patient's age group. The appearance of this patient's rash in conjunction with a history of atopic dermatitis are more strongly suggestive of eczema herpeticum.

Answer 2: Clindamycin may be used to treat bacterial skin and soft tissue infections. It offers coverage for MRSA.

Answer 4: In an infant with with a rash due to a simple viral exanthem such as roseola, supportive care and isolation would be appropriate.

Answer 5: Topical mupirocin may be used for the management of impetigo. Impetigo may also appear as a facial rash with crusting. A disseminated rash with systemic signs such as fever would be unusual in impetigo.

Bullet Summary:
Eczema herpeticum is a potentially life-threatening manifestation of herpes simplex virus infection and is managed with acyclovir.