Acute otitis media recent trends

Introduction:

Definition of acute otitis media has undergone lot of changes during recent times. According to the American Academy of Paediatrics the following criteria should be fulfilled before a diagnosis of acute otitis media could be made..

1. History of acute onset of signs & symptoms

2. Presence of middle ear effusion

3. Signs & symptoms of middle ear inflammation

The presence of middle ear infection is indicated by:

Bulging of ear drum Limited / absent mobility of ear drum Air / fluid level behind the ear drum Otorrhoea Signs & symptoms of middle ear infection include:

Erythema of ear drum Otalgia with discomfort in the ear According to American Academy of Paediatricians clinical history had a very poor predictive value in young children.

Role of Pneumatic otoscopy:

The committee constituted by American Academy of Paediatricians has stressed the important role of pneumatic otoscopy in the diagnosis of middle ear effusion. This is one of the most important clinical examination that could identify middle ear effusion. Tympanometry can atmost supplement pneumatic otoscopy because the external auditory canal of infants is highly pliable and the resultant graph would only produce a canalogram rather than tympanogram. The extreme pliability of external canal will cause the tympanometry readings to be normal even in the presence of middle ear effusion .

Before performing pneumatic otoscopy the external canal should be cleaned off cerumen / debris. The speculum used should be of proper dimensions to cause a proper seal of external auditory canal.

Pneumatic otoscopic findings to suggest the presence of middle ear effusion include:

Fullness / bulging of ear drum causing distortion to the normal cone of light Reduced / absent mobility Cloudiness of ear drum - caused by oedema in the mucosal layer Redness of the ear drum - Could be seen even in a crying child Presence if air fluid level as seen through the ear drum Major challenge to the attending physician is to discriminate between Acute otitis media and otitis media with effusion. This discrimination is a must because otitis media with effusion may commonly be caused by viral infections of the upper respiratory tract. It should also be borne in mind that otitis media with effusion may be a prelude to acute otitis media / may be caused by acute otitis media. In patients with otitis media of viral etiology it is prudent to avoid unnecessary use of antibiotics.

Pathophysiology:

Eustachean tube has commonly been implicated. Eustachean tube has been attributed with three functions:

Protection Ventilation Drainage In patients with acute otitis media it is the protective function of the eustachean tube that takes a beating.

Management:

Pain is the most troublesome part of acute otitis media. If pain is present treatment should be resorted to. A combination of Ibuprofen / paracetomol is ideal in this scenario. It should be tried out within the first 48 hours. If pain is not alleviated then Myringotomy will have to be resorted to. Role of myringotomy is not only to let out secretions from middle ear cavity, but also to obtain specimen for bacterial cultures.

Microbiology:

Causative organisms include:

Streptococcus Pneumoniae H. Influenza M. Catarrhalis Pneumococci - common in infants Role of antibiotics:

Observation of the patient without resorting to antibiotic use is an option to be considered in the following scenario:

Children above the age of 2 Aom is devoid of complications Diagnosis is pretty certain Patient is ready to attend periodic follow ups Acute otitis media in a child of less than 2 years of age is likely to cause complications. These children should be immediatly treated with a course of antibiotics. The drug of choice being ampicillin in doses of 80 - 90 mg /day in three divided doses. Lack of symptomatic improvement within 48 hours after starting the antibiotic should alert the physician the need to change the antibiotic. Drug resistance is commonly caused by Beta lactamase producing H. Influenza / M. catharrhalis. In these patients potassium clavulanate can be prescribed in addition to amoxycillin in doses of 6.4 mg / kg / day in two divided doses.

Second line antibiotics include:

Cefdinir - 14mg/kg/day in two divided doses Cefpodoxime - 10mg /kg/day single dose Cefuroxime - 30mg/kg/day in two divided doses Prevention:

Encourage breast feeding of infants Pneumococcal / Influenza vaccines Hygiene in day care centres