Age Range Affected by Hand, Foot, and Mouth Disease
HFMD predominantly affects children under 5 years of age, with the highest incidence occurring in children under 3 years old. 1, 2
Primary Age Distribution
- Children under 5 years constitute approximately 87% of all HFMD cases, representing the most susceptible population 3
- The average age of affected children is approximately 3 years, with the highest peak incidence in the 0-3 year age group 4, 5
- The median age at presentation is 25 months (approximately 2 years), with a range extending from 4 months to 11 years 3
Age-Related Disease Patterns
- Less than 3% of HFMD cases occur in individuals aged 18 years or older, making adult cases exceedingly rare 6, 1
- Severe complications, particularly neurological involvement, are most common in children under 3 years of age 2, 7
- The incidence of HFMD shows a linear decline with increasing age, with progressively fewer cases as children grow older 5
Rare Presentations in Older Populations
- Teenagers (>14 years) and adults can develop HFMD, but this is exceptionally rare 7
- When HFMD occurs in teenagers or adults, it may present with severe neurological complications including brainstem encephalitis, as documented in a 16-year-old case with EV71 infection 7
- Clinicians should maintain awareness that HFMD can occur outside the typical pediatric age range, as prompt recognition and treatment may be life-saving in these atypical presentations 7
Clinical Significance of Age
- Younger children (<5 years) have lower herd immunity to enteroviruses, which explains their higher susceptibility to HFMD 3
- The male-to-female ratio is approximately 1.3:1, showing slight male preponderance across all age groups 3
- Poor feeding due to painful oral ulcers is the primary reason for hospital admission in young children, occurring in 76.7% of hospitalized cases 3