Familial and microbiological contribution to the otitis–prone condition

ObjectiveOur group has an ongoing clinical research project investigating the immunology of the otitis–prone (OP) phenotype. In light of evidence that this condition arises from underlying immunological defects, we examined our sample population of stringently defined OP (sOP) children suffering 3 episodes of acute otitis media within 6 months or 4 within a year for a familial association with the sOP phenotype.MethodsWe analyzed the frequency of sOP within and between families and the nasopharyngeal (NP) otopathogen colonization patterns within and between families.ResultsThe presence of sOP siblings significantly predicted that additional children in the same family would likewise become sOP, with an odds ratio of 3.7 (95% CI 0.77–15.2, 95% lower bound 0.95). We further present evidence for an environmental contribution to this effect by means of prolonged exposure to otopathogens within family units.ConclusionsOP children have a significant familial association. The tendency of siblings to share similar patterns of microbial NP colonization contributes to this association. Further research is necessary to determine whether and to what extent genetics are involved.