Acute Otitis Media. Aspects of diagnosis and prophylaxis

University dissertation from Foglé-Hansson, Margaretha

Abstract: Acute otitis media (AOM) is one of the most common childhood diseases and the most common causes of antibiotic treatment in small children. Most children will experience one or two episodes of AOM during preschool age but some will suffer from repeated attacks, they will become otitis-prone. Complications with severe, sometimes fatal infections such as acute mastoiditis and meningitis are nowadays rare but does still exist. The major pathogens found in AOM are Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pyogenes. During the last decades all these common upper airway bacteria have developed various degrees of resistance against antibiotics. Several studies have related these problems to a large consumption of antibiotics especially in small children. It is of great interest to reduce the antibiotic consumption in these small children without raising the number of serious complications. In the first two studies intermittent antibiotic prophylaxis at upper respiratory tract infections (URTI) was tested as a method of reducing the number of AOM episodes in small otitis prone children. Long time prophylaxis with antibiotics have been shown to be effective but raises the antibiotic consumption very much. The prophylactic model studied here was treatment with a short-term penicillin V course of 5 days at episodes of URTI. It was shown that this seemed effective in the slightly older patients in the first study but that this method was not effective in the younger truly otitis prone children. The children in this study were treated with large quantities of pcV during the study period of one year, but there was no change in the upper airway bacteria regarding the susceptibility to betalactams in the S. pneumoniae or the ?-laktamase-production in the H. influenzae. Most complications in AOM are caused by the gram+ bacteria while most AOM caused by gram- bacteria will heal without treatment. If we could differentiate the potentially dangerous bacteria from the more harmless ones at the diagnostic moment we might be able to chose treatment more judiciously and thus lower the number of antibiotic treatments without raising the number of complications. An experimental study showed that we were able to predict the type of bacteria responsible for the infection regarding gram-positive (S. pneumoniae and S. pyogenes) and gram-negative bacteria (H. influenzae and M. catarrhalis). The same was possible in humans studied at the ENT department in Skövde during optimal conditions. In summary; prophylaxis at URTI in children with penicillin V in a short-term period did not reduce the amount of episodes of AOM in the younger truly otitis-prone children. The antibiotic susceptibility for penicillin in the S. pneumoniae during these repetitive courses of pcV did not change and the H. influenzae did not produce more ?-laktamase. It was possible to predict whether a gram+ or gram ? bacteria was the causing pathogen in an experimental and a human setting which further emphasises the need of better diagnosis in AOM.