A 75-year old diabetic patient presents with severe ear pain and granulation tissue at external auditory canal with facial nerve involvement. The most likely diagnosis is:
Ans. a. Malignant otitis externa (Ref: Dhingra 5/e p58)Presence of a painful lesion in the external ear with the evidence of granulation tissue and associated cranial nerve palsies (VII nerve) in a diabetic (or immunocompromised) patient suggest a diagnosis of malignant otitis externa.Severe hearing loss is not the chief presenting complaint malignant otitis externa.Malignant Otitis Externa:Characterized by granulation tissue in external auditory canal at the junction of bone and cartilage.MC organism: Pseudomonas aeruginosaQESR is raised, used for follow up of treatmentMalignant Otitis Externa (Necrotizing Otitis Externa/ Skull Base Osteomyelitis)Progressive debilitating and sometimes fatal infection of the external auditory canalQCharacterized by granulation tissue in external auditory canal at the junction of bone and cartilageQ.MC organism: Pseudomonas aeruginosaQPathophysiolology:Characterized by necrotizing vasculitisQThe infection does not spread through the pneumatized air tracts of the temporal bone.The otic capsule appears to be resistant to the disease process.Extensive destruction in the wall of the bony external auditory canal and osteomyelitic destruction of the wall of the fallopian canal in the descending portion of the facial nerve is seen.The infection spreads beneath the otic capsule to erode the wall of the carotid canal and then extended into the central skull base.Predisposing Factors:Diabetes (90% of patients), AIDS, aural irrigationFeatures:Occurs commonly in elderly diabetic (>60 years), immunosuppressed patients or patients who have received radiotherapy to skull baseQMore common in malesMC nerve involved: VII (Facial)Q; Others: IX, X, XI, XIIQSevere, unrelenting, deep-seated otalgia, temporal headaches, purulent otorrhea, possibly dysphagia, hoarseness, and/or facial nerve dysfunction.The pain is out of proportion to the physical examination findings.Marked tenderness is present in the soft tissue between the mandible ramus and mastoid tip.Granulation tissue is present at the floor of the osseo-cartiliginous junction. This finding is virtually pathognomonic of malignant external otitis.Otoscopic examination may also reveal exposed bone.The tympanic membrane is usually intact.Spread of the infectionDiagnosis:Investigation: CT scan, gallium and technetium-99 scintigraphyThe leukocyte count is usually normal or mildly elevated. ESR is raised.CT scanning and MRI is both useful for evaluating the anatomic extent of soft tissue inflammation, abscess formation, and intracranial complications.MRI is more sensitive for detecting intracranial complications.Treatment:Correction of immunosuppression (when possible), local treatment of the auditory canal, long-term systemic antibiotic therapy, and in selected patients, surgery.In all cases, the external ear canal is cleansed and a biopsy specimen of the granulation tissue sent for culture.IV antibiotics are directed against the offending organism.Extensive surgical debridement once an important part of the treatment is now rarely needed.Prognosis:High mortality rate (So termed as malignant)
Malignant otitis externa
Nasopharyngeal carcinoma
Acute suppurative otitis media
Chronic suppurative otitis media
Ear