Editors

AinoRuohola

PaulaTähtinen

Otitis Media in Children: Risk Factors and Pathogenesis

About 40% of children experience one or more episodes of acute otitis media (AOM) by the age of one year Cumulative Incidence of Acute Otitis Media and about 70% by the age of two years.
The incidence is highest in the age group 0.5-2 years, and the peak is around 1 year Cumulative Incidence of Acute Otitis Media.

The risk factors for AOM Diagnosis of Otitis Media: Definitions and Workup and OME Otitis Media with Effusion (Glue Ear) are largely the same, i.e. poor function of the Eustachian tube typical for a small child and immature immunology.
AOM is almost always the result of upper respiratory tract infection Viral Respiratory Infection and Acute Otitis Media.
Attendance of group child care and the presence of siblings predispose to infections Mode of Day Care, Number of Siblings and History of Otitis in the Family as Risk Factors for Acute Otitis Media.
The role of genetic predisposition is significant.
The risk is increased by parental smoking because parents who smoke have increased nasopharyngeal carriage rates for bacteria Cigarette Smoke as a Risk Factor for Otitis Media.
The use of a dummy (pacifier) has been reported to increase the risk.
A short duration of breast feeding, or none at all, increases the risk Duration of Breastfeeding as Risk Factor for Acute Otitis Media.
In the case of recurrent otitis media, it is important to inform parents about risk factors and how to influence them (see Recurrent acute otitis media and its prevention Recurrent Acute Otitis Media and its Prevention).

AOM is almost without exception associated with a respiratory tract infection Viral Respiratory Infection and Acute Otitis Media. The central pathogenic mechanism involves the interaction between viruses and bacteria. Negative pressure within the middle ear contributes towards the development of an infection.
In most children, AOM is a mixed infection caused by both bacteria and viruses.
The most common causative bacteria are Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis. Rarer bacteria include Streptococcus pyogenes, which causes, however, a significant share of complications.
Pneumococcal vaccines have reduced the relative proportion of Streptococcus pneumoniae among causative bacteria, but it remains one of the main causes of acute otitis media.
The viruses associated with AOM most frequently are rhinovirus, RS virus, enterovirus and bocavirus.
OME often develops as a consequence of AOM as the middle ear effusion does not subside and the condition becomes prolonged for over 3 months.
OME may also develop without the presence of an infection, particularly as a result of functional and/or structural problems of the Eustachian tube.

Kaur R, Morris M, Pichichero ME. Epidemiology of Acute Otitis Media in the Postpneumococcal Conjugate Vaccine Era. Pediatrics 2017;140(3):e20170181. [PubMed]
Chonmaitree T, Trujillo R, Jennings K, et al. Acute Otitis Media and Other Complications of Viral Respiratory Infection. Pediatrics 2016;137(4):. [PubMed]
Nokso-Koivisto J, Marom T, Chonmaitree T. Importance of viruses in acute otitis media. Curr Opin Pediatr 2015;27(1):110-5. [PubMed]
Hoffman HJ, Daly KA, Bainbridge KE, et al. Panel 1: Epidemiology, natural history, and risk factors. Otolaryngol Head Neck Surg 2013;148(4 Suppl):E1-E25. [PubMed]
Hafrén L, Kentala E, Järvinen TM, et al. Genetic background and the risk of otitis media. Int J Pediatr Otorhinolaryngol 2012;76(1):41-4. [PubMed]
Niemelä M, Pihakari O, Pokka T et al. Pacifier as a risk factor for acute otitis media: A randomized, controlled trial of parental counseling. Pediatrics 2000;106(3):483-8. [PubMed]