Hand, Foot & Mouth Disease

Definition

Hand, Foot & Mouth Disease (HFMD) is a common viral illness in children caused by enteroviruses, characterized by fever, oral ulcers, and vesicular rash on the hands, feet, and sometimes buttocks.

Epidemiology

• Most common in children under 5 years of age
• Occurs worldwide with seasonal peaks in summer and early autumn
• Highly contagious through respiratory droplets, contact with blister fluid, or fecal-oral route
• Outbreaks often occur in daycare centers or schools
• Usually self-limiting with low mortality, but complications are possible in infants or immunocompromised children

Etiology

• Enteroviruses: most commonly Coxsackievirus A16 and Enterovirus 71
• Transmission via respiratory secretions, saliva, blister fluid, or feces
• Close contact with infected individuals increases risk
• No specific host predisposition in otherwise healthy children
• Immunocompromised children may develop severe or prolonged illness

Pathophysiology

• Virus enters via the oropharynx or gastrointestinal tract
• Initial replication in lymphoid tissues (tonsils, Peyer’s patches)
• Viremia leads to dissemination to skin and mucous membranes
• Lesions form as vesicles on palms, soles, oral mucosa, and sometimes buttocks
• Immune response limits infection, leading to resolution in 7–10 days
• Rarely, EV71 can cause CNS involvement (meningitis, encephalitis)