Epiglottitis in a 2-year-old child occurs most commonly due to infection with:
Though the introduction of Hib vaccine has reduced the annual incidence of acute epiglottitis but still most of the pediatric cases seen today are due to haemophilus influenzae B. --Harrison 17th/ed p212 In adults it can be caused by group A streptococcus, S. pneumoniae, S. aureus and Klebsiella pneumoniae
Influenza virus
Staphylococcus aureus
Haemophilus influenzae
Respiratory syncytial virus