Coxsackievirus A6-related hand foot and mouth disease: Skin manifestations in a cluster of adult patients

Background: Hand foot and mouth disease (HFMD) is a common childhood manifestation of enterovirus (EV) infection. It predominantly affects young children, and has been mainly associated with coxsackievirus (CV) A16 and EV 71. Objectives: We report an unusual cluster of adult patients with HFMD. Study design: Throat swabs and vesicular fluid samples obtained from patients admitted to the emergency room (ER) with HFMD were tested for EV by reverse transcription (RT)-real time PCR, and further subjected to sequencing and phylogenetic analysis. Results: CVA6 was identified as the causative agent of HFMD in five epidemiologically-unrelated adult patients (28-37 years old) admitted to the ER between December 2012 and February 2013. Phylogenetic analysis mapped the CVA6 strains into one cluster. All patients manifested with fever and a severe vasculitis-like rash, followed by spontaneous recovery. Conclusions: This cluster identifies CVA6 as an emerging cause of HFMD of unusual age distribution, seasonality, and clinical severity, underscoring the need for continued alertness and clinical-genotypic surveillance of EV HFMD.