Acute Suppurative Otits Media

ACUTE SUPPURATIVE OTITIS MEDIA
  • Purulent inflammation of the muco-periosteum of the middle ear cleft
  • Predisposing factors: poor nutrition, feeding in supine position, cleft palate
  • Commonly occurs in children (because ET is shorter, straighter and wider)
  • Streptococcus pneumoniae is the most common organism causing acute otitis media.
  • It accounts for roughly 30% of the cases. Other causative organisms includes Haemophilus influenzae (20%) Moraxella catarrhalis (12%), Streptococcus pyogenes and Staphylococcus aureus.
  • 95% of all cases of invasive disease (epiglottitis, meningitis) due to H. influenzae are caused by type b organisms that possess a polyribitol phosphate capsule. Otitis media is generally not caused by type b organisms.
CLINICAL STAGES OF ASOM
  • Stage of congestion
  1. Hyperemia of mucosa
  2. Ear ache, fever, mild hearing defect
  3. Otoscopy: Injection of TM – initially along the handle of malleus, later spreading to the periphery
  4. (cartwheel sign)
  • Stage of exudation
  1. Severe pain, high fever, marked deafness, mastoid tenderness
  2. TM thickened and bulge out with loss of landmarks
  • Stage of suppuration
  1. TM may rupture, releasing pus and relieving pain
  2. Ear discharge is the main symptom
  3. A small central perforation in the pars tensa through which pulsatile discharge is seen (light house sign).
  • In acute suppurative otitis media, 85% of cases show a small perforation in antero-inferior quadrant of pars tensa.
  • Perforations in this location were associated with smooth margins, good drainage of pus, and a favorable clinical course.
  • Hence this area is termed as “perforation zone”.
  • Only 15% of perforations occurred in other locations, most typically the posterior-superior quadrant.
  1. Stage of resolution – with increased host resistance and adequate antibiotics
  2. Stage of complications
  3. Stage of Sequelae
  • Most frequently ASOM resolves without sequelae.
  • Incomplete resolution due to inadequate or resistance to antibiotics of acute suppurative otitis media may lead to development of serous/secretory otitis media.
  • Watchful waiting is recommended without immediate use of antibiotics for children with uncomplicated otitis media with effusion.
  • Close to 90% of episodes of otitis media with effusion (glue ear) resolve spontaneously after an acute otitis media episode is diagnosed. 
TREATMENT OF ASOM
  1. Medical treatment: systemic antibiotics(like Erythromycin,Penicillin or Cephalosporin), decongestants, analgesics
  • Surgical:
  1. Myringotomy 
  2. Indications of myringotomy in acute otitis media:
  3. Drum is bulging + acute pain.
  • Incomplete resolution despite antibiotics when drum remains full with persistent conductive deafness.
  1. Persistent effusion beyond 12 weeks.
  2. In Myringotomy,a circumferential incision is made in the posteroinferior quadrant of tympanic membrane, midway between handle of malleus and tympanic annulus, as it is easily accessible,damage to ossicular chain does not occur and damage to chorda tympani is avoided.
COMPLICATIONS OF ASOM
  • Mastoiditis.-Most common complication of acute otitis media in children. 
  • Labyrinthitis-In the setting of middle ear infection, bacterial infection can invade through the round window causing acute suppurative labyrinthitis. 
  • Meningitis-Infection of middle ear can spread to CNS through Cochlear Aqueduct.
  • From the labyrinth, bacteria gain access to the cochlear aqueduct, forming a conduit between the perilymph and the cerebrospinal fluid (CSF) resulting in meningeal 
  • infiltration.
  • Facial nerve palsy - an uncommon complication of ASOM
Exam Question
  • Most common site of perforation of tympanic membrane in ASOM is Anterior inferior quadrant.
  • Most common extra-cranial compli­cation of ASOM is Subperiosteal abscess.
  • 95% of all cases of invasive disease (epiglottitis, meningitis) due to H. influenzae are caused by type b organisms that possess a polyribitol phosphate capsule. Otitis media is generally not caused by type b organisms.
  • Streptococcus Pneumoniae is the most common cause of Acute otitis media in children.
  • Infection of middle ear can spread to CNS through Cochlear Aqueduct.
  • The quadrant for a myringotomy in a case of acute suppurative otitis media is Postero-inferior as it is easily accessible,damage to ossicular chain does not occur and damage to chorda tympani is avoided
  • Most frequently ASOM resolves without sequelae.
  • Cart Wheel sign is seen in ASOM.
  • Acute suppurative otitis media is treated using Erythromycin,Penicillin or Cephalosporin.
  • Pulsatile otorrhoea is seen in ASOM.
  • Light house sign is seen in ASOM.
  • Inadequate antibiotic treatment of acute suppurative otitis media may lead to Secretory Otitis Media.
  • Most common complication of acute otitis media in children is Mastoiditis.
  • Incomplete resolution despite antibiotics when drum remains full and bulging is an indication for Myringotomy in a case of ASOM.
  • Light house sign in seen in ASOM in stage of Suppuration.
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