Inflammation of the Middle Ear (Otitis Media): Causes

Pathogenesis (development of disease)

Acute otitis media usually occurs in association with a viral infection of the upper respiratory tract. The most common causative agent is respiratory syncytial virus. See the overview below for other common pathogens. However, otitis media can also be caused hematogenously or by a tympanic membrane defect. The secretions and inflammation cause relative obstruction of the auditory tuba (eustachii) – the “eustachian tube” connecting the middle ear to the nasopharynx. Normally, the mucosa of the middle ear absorbs air in the middle ear. If the air is not replaced, as may be caused by relative obstruction of the eustachian tube, negative pressure is generated, causing leakage of serous fluid. This leakage of fluid favors microbiological growth, allowing the inflammatory process to begin.

If the infection and inflammatory response is prolonged, perforation of the tympanic membrane or invasion of the surrounding air-filled spaces of the mastoid may result.

Approximately 60-80% of acute otitis media are caused by bacteria and 20-40% by viruses.

Possible pathogens include:

  • Bacteria
    • Haemophilus influenzae
    • Moraxella catarrhalis
    • Pneumococcus
    • Streptococcus pneumoniae
    • Streptococcus pyogenes – representative of GAS (group A streptococci).
    • Staphylococcus aureus
  • Mycoplasma spec. (cell wall-less bacteria)
  • Viruses
    • Respiratory syncytial viruses
    • Parainfluenza viruses
    • Influenza viruses
    • Adenoviruses
    • Enteroviruses
    • Rhinoviruses

Etiology (causes)

Biographical causes

  • Anatomic variants – Anatomic anomalies in the pharyngeal (throat) region.
  • Large pharyngeal tonsils or congenital cleft palate may result in impaired middle ear ventilation and drainage of fluid from the middle ear
  • Family history – otitis media in other family members.
  • Age – children are more commonly affected, especially between the ages of 6 months and 3 years, which can be attributed to immunologic (lack of antibodies to pneumococcus) and anatomic (low angle of the Eustachian tube) factors
  • Lack of breastfeeding – children who were breastfed during the first three months of life are less likely to be affected
  • Pacifier use – children who constantly suck on a pacifier are more likely to suffer from otitis media.

Behavioral causes

  • Consumption of stimulants
    • Tobacco (smoking) and passive smoking
  • Contact with many people increases the risk of infection

Causes due to disease

  • Gastroesophageal reflux disease (synonyms: GERD, gastroesophageal reflux disease; gastroesophageal reflux disease (GERD); gastroesophageal reflux disease (reflux disease); gastroesophageal reflux; reflux esophagitis; reflux disease; reflux esophagitis; peptic esophagitis) – inflammatory disease of the esophagus (esophagitis) caused by the pathological reflux (reflux) of acidic gastric juices and other gastric contents → chronic otitis media
  • Immunodeficiencies such as HIV disease.
  • Upper respiratory tract infections such as colds, sinusitis (sinusitis), pharyngitis (pharyngitis) or influenza.