Eczema: eczema herpeticum

Atopic patients are at risk of developing more extensive eruptions of herpes simplex (eczema herpeticum) and varicella-zoster infections when compared to non-atopic individuals. 

This chapter is set out as follows: 

• Most cases of eczema herpeticum are due to herpes simplex virus types 1 or 2 

• Usually arises during a first episode of a herpes simplex infection
• Eczema herpeticum may also complicate recurrent herpes. However, repeated episodes of eczema herpeticum are unusual
• It can affect all ages but is more commonly seen in infants and children with atopic eczema 

Cutaneous features

• Starts with clusters of itchy or painful vesicles / punched-out monomorphic erosions, which may coalesce
• Any site may be affected, most commonly the face and neck. Lesions can occur in normal skin or in sites actively or previously affected by atopic eczema or other skin conditions
• New patches form and spread over a period of 7 to 10 days, and can become widespread
• Secondary bacterial infection with staphylococci or streptococci may lead to impetigo and / or cellulitis

Systemic features

• Fever, lethargy or distress

• If the clinical diagnosis is uncertain infection can be confirmed by viral swabs taken from the base of a fresh blister, however, beware of false negative results 

• Treat suspected eczema herpeticum immediately with systemic aciclovir and discuss the same day with the on-call dermatologist as admission may be needed - systemic eczema herpeticum is uncommon, but can be fatal

• If eczema herpeticum involves the skin around the eyes, refer for same-day ophthalmological advice