Acute epiglottitis; a clinical, bacteriological and serological study.

25 patients, 15 children and 10 adults, with the clinical diagnosis of acute epiglottitis were studied. Patients severely ill on admission, 13 children and 1 adult, were immediately treated with tracheotomy and antibiotics; the remaining patients with antibiotics only. Haemophilus influenzae type b was the causative organism in all children and in 3 adults. One adult had a Diplococcus pneumoniae infection. No pathogens were isolated from the 6 remaining patients. Four of the children developed H. influenzae type b meningitis. All patients recovered. Anti-b antibodies were not demonstrable in any initial serum sample while agglutinating anti-b antibodies were found in subsequent samples (indirect hemagglutination). All patients with a type b infection had already initially precipitating anti-O antibodies against their own strain, and in most cases complement-fixing anti-O antibodies (mixed H. influenzae O antigen) with rising titers in subsequent serum samples. A possible connection between the presence of anti-O antibodies initially and the development of the acute epiglottitis is discussed.