Eczema herpeticum is a potentially serious viral infection which most commonly affects people with atopic eczema, but may also affect those with other inflammatory skin conditions.
It is caused by herpes simplex virus HSV1, but it can also be caused by other related viruses. Eczema herpeticum develops when the virus infects large areas of skin, rather than being confined to a small area as in the common cold sore.
Clinical features include:
areas of rapidly worsening, painful eczema
possible fever, lethargy or distress
clustered blisters consistent with early-stage cold sores
punched-out erosions (usually 1–3 mm) uniform in appearance which may coalesce
Suspected cases should be treated with aciclovir and referred for a dermatology opinion. Take swabs for herpes simplex virus.