CSOM: Active, Inactive (Quiescent), and Healed - Classification & Timeline

Classification Framework

Timeline: Mucosal (Tubotympanic) CSOM

Stage 1 - ACTIVE Mucosal COM

• Definition: Permanent defect of the pars tensa with inflamed middle ear mucosa producing mucopurulent discharge
• Duration criterion: Discharge present for >2-6 weeks (some sources say >6 weeks = chronic); classically discharge lasting at least 2 weeks with TM perforation = CSOM
• Clinical features:
  • Intermittent or continuous mucopurulent, non-foul smelling discharge
  • Aggravated by upper respiratory tract infections (URTIs)
  • Hearing loss typically worsens during active discharge phase (mucosal edema)
  • Middle ear mucosa: red, edematous, velvety on otoscopy
  • Central (safe) perforation of pars tensa

Stage 2 - INACTIVE / QUIESCENT Mucosal COM

• Definition: Permanent perforation of the pars tensa is still present, but the middle ear mucosa is NOT inflamed - dry ear
• Duration criterion: No discharge for 6 months = inactive/quiescent stage (per clinical exam viva criteria)
• Clinical features:
  • Dry central perforation
  • No active infection or discharge
  • Conductive hearing loss persists
  • Middle ear mucosa appears normal
  • Lamina propria around the perforation may be thickened
  • Mucocutaneous junction is at the margin of the perforation
  • Tympanoplasty is the ideal time to operate - ear must be dry before surgery

Stage 3 - HEALED Chronic Otitis Media

• Definition: Permanently controlled infection that has resolved; TM is intact but abnormal
• Ways the TM can heal:
  1. Dimeric (atrophic) membrane - thin, flaccid healed perforation
  2. Tympanosclerosis (chalk patches) - calcification in the healed TM
  3. Retraction (myringitis) - inward retraction due to negative middle ear pressure
  4. Cholesterol granuloma

Timeline: Squamosal (Atticoantral) CSOM

Stage 1 - INACTIVE Squamosal COM (Retraction Pocket)

• Posterosuperior retraction of pars flaccida or pars tensa
• No active infection yet, but at risk of accumulating keratin debris
• Can flip to active at any time

Stage 2 - ACTIVE Squamosal COM (Cholesteatoma)

• Retraction pocket begins accumulating keratin debris and becomes infected
• Foul-smelling, scanty, purulent discharge - NOT relieved by medications
• Attic or posterosuperior (marginal) perforation
• Bone erosion - the "unsafe/dangerous" hallmark
• Risk of serious complications: facial nerve palsy, labyrinthine fistula, meningitis, intracranial abscess

Key Time Points Summary

Exam Viva Points

• Active = discharge present NOW, mucosa inflamed
• Inactive/Quiescent = dry ear for ≥6 months, perforation still there
• Healed = perforation closed but TM is abnormal (atrophic, tympanosclerosis, retraction)
• Pure Tone Audiometry (PTA) should be done only when the ear is dry (inactive stage) - not during active discharge
• In active stage: medical management first (aural toileting + topical ciprofloxacin drops + systemic antibiotics)
• In inactive stage: surgical management (tympanoplasty ± ossiculoplasty)
• Safe CSOM usually responds to medications; unsafe CSOM usually does NOT respond