Epiglottitis in a 2-year-old child occurs most commonly due to infection with:
Influenza virus
Staphylococcus aureus
Haemophilus influenzae
Respiratory syncytial virus
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