title: Coxsackievirus A6 associated hand, foot and mouth disease in adults: clinical presentation and review of the literature.
abstract: Hand, foot, and mouth disease (HFMD) is generally considered a rare illness in adults. Classically, HFMD has been strongly associated with coxsackievirus strain A16 and enterovirus 71. The coxsackievirus A6 (CVA6) strain has been linked to severe worldwide outbreaks since 2008. CVA6 is associated with a more severe and profound course of disease, affecting both children and adults.
  
  
  
  To present a series of five adult patients diagnosed with HFMD due to CVA6. We investigate method of diagnosis and compare clinical presentation of adult cases to those in children.
  
  
  
  Each patient underwent a full-body skin exam as well as inspection of the oral cavity. Rapid plasma reagin (RPR) and serologic assays by complement fixation against coxsackievirus B (1-6) and A (2,4,7,9,10,16) were performed as indicated. As standard serological testing does not detect CVA6, real-time reverse transcription-polymerase chain reaction (qRT-PCR) of serum, buccal swabs, and skin scrapings were performed by the Centers for Disease Control and Prevention (CDC).
  
  
  
  Each patient had clinical findings consistent with various stages of HFMD. One patient presented with delayed onychomadesis and desquamation of the palms and soles. RPR and serologic assays by complement fixation against CVB (1-6) and CVA (2,4,7,9,10,16) were mostly negative, although elevated in two patients due to cross-reactivity. qRT-PCR identified CVA6 genetic material in samples from all patients.
  
  
  
  This series demonstrates that there is a wide array of disease presentation of CVA6 associated HFMD in adults.
authors.affiliation: Center for Clinical Studies, Houston, TX, USA; Department of Dermatology, Tufts Medical Center, Boston, MA, USA.
authors.forename: Marigdalia K
authors.initials: MK
authors.lastname: Ramirez-Fort
authors.affiliation: Center for Clinical Studies, Houston, TX, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Downing
authors.affiliation: Department of Dermatology, University of Texas Health Science Center at Houston, Houston, TX, USA.
authors.forename: Hung Q
authors.initials: HQ
authors.lastname: Doan
authors.affiliation: Department of Dermatology, University of Texas Health Science Center at Houston, Houston, TX, USA.
authors.forename: Frances
authors.initials: F
authors.lastname: Benoist
authors.affiliation: Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: M Steven
authors.initials: MS
authors.lastname: Oberste
authors.affiliation: Center for Clinical Studies, Houston, TX, USA.
authors.forename: Farhan
authors.initials: F
authors.lastname: Khan
authors.affiliation: Center for Clinical Studies, Houston, TX, USA; Department of Dermatology, University of Texas Health Science Center at Houston, Houston, TX, USA. Electronic address: styring@ccstexas.com.
authors.forename: Stephen K
authors.initials: SK
authors.lastname: Tyring
mesh_terms: D000293:Adolescent; D000328:Adult; D003168:Complement Fixation Tests; D003384:Coxsackievirus Infections / Q000175:diagnosis*; D004196:Disease Outbreaks; D018450:Disease Progression; D004770:Enterovirus / Q000145:classification*; D005260:Female; D006232:Hand, Foot and Mouth Disease / Q000175:diagnosis* / Q000635:transmission / Q000821:virology*; D006801:Humans; D008297:Male; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055815:Young Adult
keywords: Coxsackievirus A6; Enterovirus; Hand foot and mouth disease