Resolution of Hand, Foot, and Mouth Disease With Valacyclovir

Hand, foot, and mouth disease (HFMD) is a common viral illness that predominantly affects young children, with approximately 95% of cases occurring in individuals under the age of 5. While typically self-limiting, a subset of cases may present with more severe cardiopulmonary and neurological sequelae, such as myocarditis, pneumonia, meningitis, and encephalitis. Management is primarily supportive, as no standard antiviral therapy currently exists. However, previous case reports have suggested that acyclovir may offer therapeutic benefits. We present a case of a healthy 39-year-old female who experienced dramatic symptomatic improvement within 10 hours and complete resolution within 48 hours following off-label valacyclovir use. This case raises the possibility of valacyclovir use in adults with HFMD and highlights the need for further research to validate its role.