Deep Herpes in an Adolescent With Severe Atopic Dermatitis and Concurrent Methicillin-Resistant Staphylococcus aureus (MRSA) Bacteremia.

Herpes simplex virus (HSV) infection is a well-recognized complication of atopic dermatitis, most commonly presenting as eczema herpeticum. Deep herpes is a recently described clinicopathologic manifestation of HSV infection, characterized by viral involvement of cutaneous stromal cells with limited or absent epidermal infection, which can make diagnosis challenging when classic histopathologic findings are absent. We report a 17-year-old adolescent with severe atopic dermatitis who presented with fever and a rapidly progressive painful erosive eruption. Evaluation revealed methicillin-resistant Staphylococcus aureus (MRSA) bacteremia. Skin biopsy demonstrated a hyperplastic spongiotic epidermis with a superficial and mid-dermal inflammatory infiltrate. Although characteristic epidermotropic HSV cytopathic changes were absent, HSV-2 immunohistochemistry identified infected cells within the dermal inflammatory infiltrate, supporting a diagnosis of deep herpes. The patient demonstrated rapid clinical improvement following treatment with intravenous acyclovir and vancomycin, with cessation of new lesion formation, progressive re-epithelialization, and resolution of systemic symptoms.  This case highlights deep herpes as an uncommon manifestation of HSV infection in an adolescent with severe atopic dermatitis complicated by concurrent MRSA bacteremia. Pediatricians should consider deep herpes in patients with severe atopic dermatitis who present with painful erosive eruptions and systemic symptoms, particularly when clinical findings and routine diagnostic testing are inconclusive.