Since late 2011, at least 36 cases of atypical Hand, Foot, and Mouth Disease (HFMD) associated with Coxsackievirus A6 (CVA6) have been identified in California. Additional cases have been reported throughout the United States. Some cases have experienced severe fever and extensive rash, often involving entire extremities, the face, buttocks, trunk, and areas of previous skin disease or damage (e.g., eczema, dermatitis, sunburn). Onychomadesis (nail shedding) and/or skin desquamation was described in several cases and some patients presented with large, hemorrhagic blisters. Not only are atypical features being seen, but cases are also being noted in older children, adolescents, and adults. No deaths have been associated with reported cases in the United States.
Hospitalization is more common for atypical (vs. typical) HFMD, the risk of transmission is potentially greater, and there is no specific treatment. For these reasons, local clinicians are requested to report hospitalized and/or severely symptomatic cases of suspected atypical HFMD to the Epidemiology and Immunization Services Branch via Confidential Morbidity Report (CMR) form, faxed to (858) 715-6458. Outbreaks of suspected atypical HFMD should also be reported.
Standard enterovirus PCR testing will not differentiate between CVA6 and other enteroviruses. Therefore, clinicians are advised to collect throat and vesicle swabs within 48-72 hours of symptom onset from all hospitalized and/or are severely symptomatic cases of suspected atypical HFMD. Specimens should be stored in viral transport media and delivered to the San Diego County Public Health Laboratory for identification via sequencing/serotyping at the California Department of Public Health, Viral and Rickettsial Disease Laboratory. A specimen submission form is included as the second page of this alert.
Enteroviruses are spread by the respiratory and fecal-oral routes, and from contact with vesicles/blisters or their fluid. Patients with atypical HFMD should be educated about the importance of hand and respiratory hygiene, disinfection of surfaces and fomites, avoidance of sharing personal items, and exclusion from child care settings until they are afebrile for at least 24 hours and lesions are healed or scabbed and are no longer draining.
For more information about typical and atypical HFMD, please visit the following CDC website: http://www.cdc.gov/hand-  foot-mouth/index.html.