When to Start Antiviral Therapy in Eczema Herpeticum

Prompt antiviral treatment is key to help prevent hospitalisation in this dermatological emergency

Eczema herpeticum

What is it?

People with atopic eczema are susceptible to many cutaneous superinfections, with bacteria (especially Staphylococcal) and viruses (especially herpes simplex).

Eczema herpeticum is due to herpes simplex superinfection in atopic eczema and can be a serious and even life-threatening complication.

It should be considered when there is:

Any sudden deterioration in atopic eczema
Skin pain
Development of typical herpetic lesions – they are initially vesicles, 1-2 mm in diameter, and are arranged as clusters. They will crust over a few days; the crusts will fall off and clustered superficial, punched out erosions will be seen. The resulting lesions can become confluent and often have a jagged margin.
Lymphadenopathy in adjacent nodes

Key points:

Skin swabs and PCR should be taken, but treatment should be initiated on clinical suspicion, as delays will result in progression.
Start antiviral therapy promptly
Oral aciclovir 400–800 mg 5 times daily, or, if available, valaciclovir 1 g twice daily, for 10–14 days or until lesions heal.
Intravenous aciclovir is prescribed if the patient is too sick to take tablets, or if the infection is deteriorating despite treatment.
Stop immunosuppressants including potent topical steroids and tacrolimus.
As impetiginisation is so common, start an anti-staphylococcal antibiotic.
Consult an ophthalmologist when eyelid or eye involvement is seen or suspected.

Why it matters:

Eczema herpeticum is considered one of the few dermatological emergencies. Prompt treatment with antiviral medication should eliminate the need for hospital admission.