-IBIS-1.5.0-
tx
eyes/ears/nose/throat
otitis media
diagnoses
definition and etiology
definition: Acute otitis media is a viral or bacterial infection of the middle ear, usually secondary to a URI. It is most common in children 6 to 36 months old and then again at 4-7 years old. It is the most frequent diagnosis of children in a clinical setting, and it is estimated that about 2 billion dollars are spent each year for conventional medical and surgical treatment of the condition. See "course/prognosis" for information on serous OM.
etiology: The Eustachian tube is the focal point of concern in most cases of acute otitis media. The eustachian tube protects the middle ear from nasopharyngeal secretions, regulates gas pressure in the middle ear, prevents bacteria and viruses from having easy access into the middle ear from the mouth and nasopharnyx, and clears secretions from the middle ear. In the child, the tube is at a horizontal level in the head (the tube becomes slightly vertical in the adult), making it easier for organisms to move from the nasopharynx into the middle ear. The tube opens during the act of swallowing due the contraction of the tensor veli palatini muscle. Obstruction of the tube and/or abnormal patency are the initiating factors causing acute otitis media. Obstruction may be:
1. Functional : Due to an abnormal opening mechanism and/or increased tubal compliance.
2. Mechanical: Due to abnormal hyperplasia of the tissues around the tubes opening into the nasopharynx or swelling of the tube itself.
3. From an infection or allergy affecting nearby tissues causing them to swell and occlude the tube.
In infants, the bacteria most involved are E. coli and S. aureus; in older children (but less than 8 years old), the most common bacteria are S. pneumonia, H. influenza, Group A-beta hemolytic streptococci, and S. aureus. Over 8 years of age H. influenza is less involved in infections of the ear and the other three bacteria are the main causes. OM usually begins when a viral URI or acute otitis media experiences secondary invasion by one of these bacterial organisms.
Causative factors involved in susceptibility include substituting early bottle feeding for breast feeding. Human breast milk seems to have a prophylactic effect on a baby, although the exact reason why is not understood: that is, whether it has more to do with an intolerance to the cow's milk or the natural immune boost provided by mother's milk, or a combination of both. A related factor to bottle feeding is that supine feeding with the bottle has been shown to cause regurgitation of the milk which then has a chance of entering the Eustachian tube. Another very common etiological factor in children is one or more food or inhalant allergies. Allergens may cause acute otitis media by causing mucus production and mucous membrane swelling. Once the allergens are discovered and removed from the child's environment or diet, health can greatly improve. Common food allergens in children include cow's milk, wheat, soy, corn, citrus, and egg, although other foods may be implicated on an individual basis. Inhalant allergies include molds, dust, animal dander, and hay fever.
Pre-teen OM seems to be related to true food allergies while OM in adults (20+) to be mostly food sensitivities. (Easley)
signs and symptoms
The initial complaint of AOM is usually that of a persistent painful earache.
Children may pull on their ear or bore their finger into the canal.
The child's mood may often change to irritability or clinginess.
There is not infrequently a history of recent viral URI, although eustachian tube obstruction from any cause can lead to infection.
Hearing loss may occur but is not that common.
Fever (up to 105°F/40.5°C), chills, nausea, vomiting and diarrhea may be present.
Tympanic membrane is hyperemic, opaque, and bulging: the cone of light is displaced, and the landmarks are hard to discern.
Insufflation shows a tympanic membrane that does not move.
If the tympanic membrane spontaneously ruptures, there is significant pain relief associated with the flow of bloody, serous, and/or purulent otorrhea.
lab findings:
WBCs may be increased.
(+) food allergy or other allergen testing.
positive culture of any discharge
course and prognosis
The potential complications of AOM include acute mastoiditis; petrositis; brain abscess; facial paralysis; epidural abscess; labyrinthitis; hearing loss (conductive and sensorineural); meningitis; subdural empyema; lateral sinus thrombosis; otitic hydrocephalus; and the development of serous otitis media. Symptoms of the beginning of one of the serious complications (all but serous OM) include headache, chills and fever, vertigo, and sudden severe hearing loss. The typical course for a child having recurrent infections and seeing an M.D. for treatment would be continuous use of antibiotics, tympanostomy tubes, tonsillectomy and adenoidectomy, although these procedures have no significant efficacy in the literature when compared to treatment with placebo. If a child is taken off of foods s/he is intolerant of and avoids other allergens, a complete cessation of AOM episodes may often ensue.
Serous otitis media (SOM): also known as secretory or nonsuppurative otitis media: is a chronic effusion in the middle ear, resulting from the incomplete resolution of AOM or a chronic obstruction of the eustachian tube. It may be recognized by seeing an air fluid level or bubbles behind the tympanic membrane with otoscopy, as well as retraction of the membrane, a displaced light reflex, and an ability to see the landmarks more distinctly. It is found in 20-40% of children under 6 years old and may cause conductive hearing loss. On culture, the exudate present is usually sterile but may contain pathogenic bacteria. Allergies have been firmly implicated in patients with SOM: either inhalant (16%), food (14%), or both (70%). Patients who are treated for allergies by removing the offending antigen and/or by desensitization show a very good success rate in curing SOM.
differential diagnosis
Otitis externa.
Foreign object in the ear.
Head trauma causing serous or bloody fluid leakage from ear.
footnotes