Atypical Hand, Foot, and Mouth Disease Caused by Coxsackievirus A6 in Denmark: A Diagnostic Mimicker

Since 2008, outbreaks of atypical hand, foot, and mouth disease (HFMD) in children and adults have been reported worldwide. The majority of these outbreaks are caused by a new lineage of Coxsackie virus A6 (CV-A6) presenting a more severe clinical phenotype than the classical childhood HFMD caused by CV-A16. Between June 2014 and January 2016, 23 cases of atypical HFMD disease presented at a Dermatology Department at a regional University Hospital in Denmark. Patients were referred by general practitioners and dermatologists with a variety of clinical diagnoses, including eczema herpeticum, vasculitis, syphilis, dermatophytid, erythema multiforme and Stevens-Johnson syndrome. Three adults and 3 children required hospitalization due to extensive skin involvement and fever. All reported patients had laboratory-confirmed enterovirus infection. This study demonstrated an up-surge in atypical HFMD caused by CV-A6 in the Region of Southern Denmark and that atypical HFMD can be difficult to diagnose clinically as it may mimic other severe skin diseases.