Pus in the middle ear.
Usually children. This is more of an adult guide, as I have never consulted on a case of otitis media. My children never had it. Neener neener.
Streptococcus pneumoniae, and/or Haemophilus influenzae (unencapsulated) (the big 2), then alpha-Streptococci, Moraxella catarrhalis (PubMed). 66% will have both bacteria and viruses with Picornaviruses accounting for 60% of all viral etiologies (PubMed).
In the Cochrane review of 2010 (PubMed), the risk for treatment failure was higher with short courses (< 7 d) of antibiotics (21% failure) vs longer courses (>= 7d ) (18% failure). But if I have learned nothing else in the last 5 years, I do not really trust the Cochrane reviews anymore.
10 days therapy is better than five in kids (PubMed).
In a randomized trial of children 6 to 35 months treatment failure occurred in 18.6% of the children who received Amoxicillin/clavulanate, as compared with 44.9% of the children who received placebo and, what a surprise, the antibioitc group had diarrhea (PubMed). Augmentin is probably better than GoLytely for gettin' them bowels a movin'.
In kids, 7 days of amoxicillin/clavulanate reduced the duration of middle ear effusion (MEE) by two weeks and possible concomitant hearing impairment in children with AOM and reduced the risk for persistent MEE (PubMed). It's all about MEE MEE MEE. So self centered
Adults, as a rule, do not get otitis media. They have Wegener's, perhaps an immunoglobulin deficiency or immotile cilia syndrome. I see an adult with otitis media, I get an ANCA, quantitative immunoglobulins and IgG subtypes. It can be a manifestation of an immunodeficiency.
Tubes treated with quinolone ear drops have increased risk of perforations requiring tympanoplasty, a complication exaggerated by corticosteroids.(PubMed).
Relevant links to my Medscape blog