55 years old uncontrolled diabetic patient presents with fever and severe pain in the right ear with active pus discharge since three days. On examination granulation tissue is evident in the external auditory canal. What is the most probable diagnosis?
Ans. is 'b' i.e., Malignant otitis externa Malignant otitis externa* Malignant otitis externa, also called necrotizing external otitis, is a misnomer as it is not a neoplastic condition, rather it is an infectious condition. Malignant otitis externa is a disorder involving inflammation and damage of the bones and cartilage at the base of skull in temporal bone as a result of spread of infection from outer ear.* Malignant otitis externa is often caused by difficult to treat bacteria such as pseudomonas aeruginosa. Only rare cases of malignant otitis externa due to S. aureus, Proteus mirabilis and Aspergillus fumigatus have been reported. The infection spreads from the floor of the ear canal to the nearby tissues and into the bones at the base of the skull. The infection and inflammation may damage or destroy the bones. The infection may spread more and affect the cranial nerves, brain, or other parts of the body.Predisposing factors for malignant otitis externa* Elderly diabetics (most common predisposing factor)* Individuals with altered immune function (immunodeficiency)* ChemotherapyClinical features of malignant otitis externa* Severe pain inside the ear and may get worse when moving head.* Granulation tissue in the external auditory canal, at the junction of bony and cartilagenous part.* Drainage from the ear - yellow, yellow - green, foul smelling, persistent.* Fever* Itching of ear or ear canal* Troubled swallowing & weakness of face.Complications* Cranial nerve palsies most commonly facial nerve is involved. Other cranial nerves can also be involved (glossopharyngeal, vagus, spinal accessory, hypoglossal, abducens, trigeminal).* Jugular venous thrombosis* Cavernous sinus thrombosis* MeningitisTreatment of malignant otitis externa* In all cases, the external ear canal is cleansed and a biopsy specimen of the granulation tissue sent for culture.* IV antibiotics is directed against the offending organism. For Pseudomonas aeruginosa, the most common pathogen, the regimen involves an antipseudomonal penicillin or cephalosporin (3rd generation piperacillin or ceftazidime) with an aminoglycoside.* A fluoroquinolone antibiotic can be used in place of the aminoglycoside.* Ear drops containing antipseudomonal antibiotic e.g. ciproflaxacin plus a glucocorticoid is also used.* Early cases can be managed with oral and otic fluoroquinolones only.* Extensive surgical debridement once an important part of the treatment is now rarely needed.Radiology in malignant otitis externa* To look for signs of a bone infection next to the ear canal, the following tests may be performedi) CT scan of the head# A CT scan defines the anatomical extent of the disease and remains the initial investigation of choice.ii) MRI of the head# MRI scanning is useful for asessing the initial severity of the disease and is excellent at delineating the extent of soft tissue disease present and intracranial complications.iii) Radioisotope scans (technetium 99/gallium 67)# A base line gallium scan is obtained for comparison followed by serial scans to monitor treatment response.# Radioactive labelled white cell scans have a role in assessing the presence and degree of osteomyelitis.
Serous otitis media
Malignant otitis externa
Carcinoma of external auditory canal
Otitis media
Ear