Eczema varicellicum has been reported, and it has been suggested that some cases of EH may actually be caused by VZV as the 2 are clinically indistinguishable and less than half of EH cases are diagnosed with laboratory confirmation.8
Confirm Dx before you treat
To guide management, cases of suspected eczema coxsackium should be confirmed, and HSV/VZV should be ruled out.9 Testing modalities include swabbing vesicular fluid for enterovirus polymerase chain reaction (PCR) analysis (preferred modality), oropharyngeal swab up to 2 weeks after infection, or viral isolate from stool samples up to 3 months after infection.2,3
Treatment for eczema coxsackium involves supportive care such as intravenous (IV) hydration and antipyretics. Some studies show potential benefit with IV immunoglobulin in treating severe HFMD, while other studies show the exacerbation of widespread HFMD with this treatment.7,10
Prompt diagnosis and treatment for eczema coxsackium is critical to prevent unnecessary antiviral therapy and to help guide monitoring for associated morbidities including Gianotti-Crosti syndrome–like eruptions, purpuric eruptions, and onychomadesis.
Our patient. Because EH was in the differential, our patient was started on empiric IV acyclovir 10 mg/kg every 8 hours while test results were pending. In addition, she received acetaminophen, IV fluids, gentle sponge baths, and diligent emollient application. Scraping from a vesicle revealed negative herpes simplex virus 1/2 PCR, negative VZV direct fluorescent antibody, and a positive enterovirus PCR—confirming the diagnosis of eczema coxsackium. Interestingly, a viral culture was negative in our patient, consistent with prior reports of enterovirus being difficult to culture.11
With confirmation of the diagnosis of eczema coxsackium, the IV acyclovir was discontinued, and symptoms resolved after 7 days.
CORRESPONDENCE
Shane M. Swink, DO, MS, Division of Dermatology, 1200 South Cedar Crest Boulevard, Allentown, PA 18103; shanesw@pcom.edu