Malignant Otitis Externa — MCQs
All are intracranial complications of otitis media except which of the following?
Which of the following statements about malignant otitis externa is true?
Progressive loss of hearing, tinnitus and ataxia are commonly seen in a case of -
A 60-year-old diabetic patient presents with an extremely painful lesion in the external ear and otorrhea that is not responding to antibiotics, accompanied by granulation-type tissue in the external ear, bony erosion, and facial nerve palsy. The most likely diagnosis is
A 60-year-old diabetic presents with otalgia, otorrhea, and granulation tissue in EAC. Empiric treatment should include:
All of the following are true about malignant otitis externa except which of the following?
An old diabetic male presented with rapidly spreading infection of the external auditory canal with involvement of the bone and presence of granulation tissue. The drug of choice for this condition is:
Which of the following associations is true regarding facial nerve palsy in temporal bone fractures?
All of the following are true about transverse fractures of the temporal bone EXCEPT:
A patient with a sinus infection develops chemosis, bilateral proptosis, and fever. What is the most likely diagnosis?
Malignant Otitis Externa Indian Medical PG Practice Questions and MCQs
Question 1: All are intracranial complications of otitis media except which of the following?
- A. Brain abscess
- B. Hydrocephalus
- C. Lateral sinus thrombophlebitis
- D. Facial nerve palsy (Correct Answer)
Explanation: ***Facial nerve palsy*** - This is an **extracranial complication** of otitis media affecting the **facial nerve within the temporal bone**, not an intracranial structure. - The facial nerve (CN VII) runs through the **fallopian canal** in the temporal bone and can be affected by inflammation from adjacent mastoid or middle ear infection. - Classified as a **temporal bone complication** rather than an intracranial complication. *Lateral sinus thrombophlebitis* - This is a true **intracranial complication** involving thrombosis of the **sigmoid and lateral venous sinuses** within the cranial cavity. - Results from direct extension of infection through the **mastoid tegmen** or via septic thrombophlebitis. - Presents with features of sepsis, headache, and papilledema. *Brain abscess* - A severe **intracranial complication** representing focal suppurative infection within the **brain parenchyma** (commonly temporal lobe or cerebellum). - Occurs through direct extension via bony erosion, retrograde thrombophlebitis, or hematogenous spread. - Requires urgent neurosurgical intervention. *Hydrocephalus* - An **intracranial complication** that can occur secondary to **otogenic meningitis** or **lateral sinus thrombosis**. - Results from impaired CSF absorption or obstruction of CSF pathways. - More common in pediatric otitis media with CNS complications.
Question 2: Which of the following statements about malignant otitis externa is true?
- A. Not painful
- B. Common in diabetics and old age (Correct Answer)
- C. Caused by streptococcus
- D. Responds to topical antibiotics alone
Explanation: ***Common in diabetics and old age*** - **Malignant otitis externa** is an aggressive infection primarily affecting the external auditory canal and surrounding structures. - It most commonly occurs in **immunocompromised individuals**, especially **elderly diabetics**, due to impaired immune response and microvascular complications. *Not painful* - Malignant otitis externa is characterized by **severe, unrelenting otalgia (ear pain)** that often worsens at night and is disproportionate to the clinical findings. - The pain is due to the **inflammatory and destructive process** involving cartilage, bone, and nerves. *Caused by streptococcus* - The most common causative organism for malignant otitis externa is **Pseudomonas aeruginosa** (>90% of cases), not Streptococcus. - **Streptococcus species** are more commonly associated with acute otitis media or common skin infections. *Responds to topical antibiotics alone* - Malignant otitis externa requires **prolonged systemic antibiotic therapy** (typically 4-6 weeks of intravenous or oral fluoroquinolones like ciprofloxacin). - Topical antibiotics alone are **insufficient** due to the invasive nature of the infection, which extends beyond the external canal to involve bone and soft tissues.
Question 3: Progressive loss of hearing, tinnitus and ataxia are commonly seen in a case of -
- A. Acoustic neuroma (Correct Answer)
- B. Otitis media
- C. Ependymoma
- D. Cerebral glioma
Explanation: ***Acoustic neuroma*** - This benign tumor arises from the **vestibulocochlear nerve (cranial nerve VIII)**, leading to **progressive unilateral hearing loss**, **tinnitus**, and **ataxia** as it compresses the adjacent cerebellum [1]. - The symptoms are progressive and often insidious, reflecting the slow growth of the tumor, and are highly characteristic for this condition [1]. *Otitis media* - **Otitis media** is an **inflammation/infection of the middle ear**, primarily causing ear pain, ear discharge, and conductive hearing loss. - While it causes hearing loss, it typically presents with acute symptoms and does not typically cause **tinnitus** or **ataxia** unless there are severe complications affecting the inner ear or brain. *Ependymoma* - **Ependymomas** are tumors originating from the **ependymal cells** lining the ventricles and spinal cord, often causing symptoms related to increased intracranial pressure (headache, nausea) or spinal cord compression. - They do not typically present with the specific triad of **progressive hearing loss**, **tinnitus**, and **ataxia** characteristic of acoustic neuroma. *Cerebral glioma* - **Cerebral gliomas** are brain tumors that arise from glial cells and present with a wide range of neurological symptoms depending on their location, such as **seizures**, **weakness**, or **cognitive changes**. - They are unlikely to present with the specific combination of **progressive hearing loss**, **tinnitus**, and **ataxia** unless located in the brainstem or cerebellum in a way that specifically compresses the eighth cranial nerve and cerebellar pathways, which is less common than for an acoustic neuroma.
Question 4: A 60-year-old diabetic patient presents with an extremely painful lesion in the external ear and otorrhea that is not responding to antibiotics, accompanied by granulation-type tissue in the external ear, bony erosion, and facial nerve palsy. The most likely diagnosis is
- A. Malignant otitis externa (Correct Answer)
- B. Nasopharyngeal carcinoma
- C. Chronic suppurative otitis media
- D. Acute suppurative otitis media
Explanation: **Malignant otitis externa** - The combination of **severe ear pain**, **granulation tissue** in the external ear, **bony erosion**, **facial nerve palsy**, and unresponsiveness to antibiotics in a **diabetic patient** is highly characteristic of malignant otitis externa. - This aggressive infection, typically caused by *Pseudomonas aeruginosa*, can spread from the external auditory canal to the surrounding bone and soft tissues, leading to cranial nerve involvement. *Nasopharyngeal carcinoma* - While nasopharyngeal carcinoma can cause cranial nerve palsies due to local invasion, it typically presents with symptoms such as **nasal obstruction**, **epistaxis**, or **unilateral serous otitis media** due to Eustachian tube obstruction. - It would not typically manifest with severe external ear pain, otorrhea, or visible granulation tissue in the external auditory canal. *Chronic suppurative otitis media* - Chronic suppurative otitis media is characterized by **persistent ear discharge** through a tympanic membrane perforation and can lead to **cholesteatoma** formation. - While it can cause bony erosion and, in advanced cases, facial nerve palsy, it is less likely to present with the severe external ear pain and granulation tissue pattern described in this diabetic patient, who is more susceptible to aggressive external ear infections. *Acute suppurative otitis media* - Acute suppurative otitis media is an infection of the **middle ear**, typically presenting with ear pain, fever, and a **bulging tympanic membrane**. - It does not involve granulation tissue in the external ear, bony erosion, or facial nerve palsy as initial symptoms, and it primarily affects the middle ear cavity, not the external auditory canal or surrounding bone.
Question 5: A 60-year-old diabetic presents with otalgia, otorrhea, and granulation tissue in EAC. Empiric treatment should include:
- A. Fluconazole
- B. Cloxacillin oral
- C. Anti-pseudomonal therapy IV (Correct Answer)
- D. Ciprofloxacin with steroids
Explanation: ***Anti-pseudomonal therapy IV*** - The constellation of **otalgia**, **otorrhea**, **granulation tissue in the external auditory canal (EAC)**, and **diabetes** in an elderly patient is highly suggestive of **necrotizing (malignant) otitis externa**. - This condition is almost exclusively caused by **Pseudomonas aeruginosa**, requiring prompt and aggressive systemic anti-pseudomonal antibiotic therapy. *Fluconazole* - **Fluconazole** is an antifungal medication, while necrotizing otitis externa is primarily a bacterial infection. - While fungal infections can occur in the ear, the classic presentation described strongly points to a bacterial etiology, specifically *Pseudomonas*. *Cloxacillin oral* - **Cloxacillin** is a penicillinase-resistant penicillin primarily active against staphylococcal and streptococcal infections. - It does not provide adequate coverage against **Pseudomonas aeruginosa**, the causative agent of necrotizing otitis externa, and an oral route is insufficient for this severe infection. *Ciprofloxacin with steroids* - Oral **ciprofloxacin** is commonly used for *Pseudomonas* infections, but the severity and potential for skull base osteomyelitis in necrotizing otitis externa typically necessitate **intravenous therapy** initially. - **Steroids** are generally contraindicated in active infections like necrotizing otitis externa as they can suppress the immune response and worsen the infection.
Question 6: All of the following are true about malignant otitis externa except which of the following?
- A. Pseudomonas is the most common cause
- B. Severe hearing loss is the chief presenting complaint (Correct Answer)
- C. ESR is used for follow up after treatment
- D. Granulation tissues are seen on the floor of the external auditory canal
Explanation: ***Severe hearing loss is the chief presenting complaint*** - While otitis externa can cause mild to moderate conductive **hearing loss** due to swelling and debris, severe hearing loss is **not** typically the chief presenting complaint of **malignant otitis externa**. Instead, patients usually present with severe **otalgia** (ear pain), **otorrhea** (ear discharge), and granulation tissue in the external auditory canal. - The hallmark presentation is **severe, unrelenting otalgia** that is out of proportion to clinical findings, often worse at night. Hearing loss is a secondary feature, not the primary complaint. *ESR is used for follow up after treatment* - **Erythrocyte Sedimentation Rate (ESR)** is a valuable marker for assessing inflammatory activity in **malignant otitis externa** and is commonly utilized to monitor treatment response. - A decrease in ESR indicates successful treatment and resolution of the infection, making it a reliable tool for follow-up. *Granulation tissues are seen on the floor of the external auditory canal* - The presence of **granulation tissue** at the bony-cartilaginous junction of the external auditory canal, particularly on the **floor (inferior wall)**, is a hallmark diagnostic sign of **malignant otitis externa**. - This finding at the floor of the EAC is a classic and highly specific sign indicating osteomyelitis of the temporal bone. *Pseudomonas is the most common cause* - **Pseudomonas aeruginosa** is indeed the predominant pathogen responsible for approximately **90-95%** of **malignant otitis externa** cases. - This gram-negative bacterium is particularly opportunistic in immunocompromised individuals, especially elderly diabetics.
Question 7: An old diabetic male presented with rapidly spreading infection of the external auditory canal with involvement of the bone and presence of granulation tissue. The drug of choice for this condition is:
- A. Ciprofloxacin (Correct Answer)
- B. Second generation cephalosporin
- C. Penicillin
- D. Aminoglycosides
Explanation: ***Ciprofloxacin*** - This clinical presentation describes **necrotizing otitis externa (NOE)**, a severe infection predominantly caused by **Pseudomonas aeruginosa**. - **Ciprofloxacin** is the drug of choice due to its excellent anti-pseudomonal activity and good tissue penetration, necessary to treat the extensive infection involving bone. *Penicillin* - **Penicillin** has limited activity against **Pseudomonas aeruginosa**, which is the primary pathogen in necrotizing otitis externa, making it ineffective. - Its spectrum of activity is primarily against gram-positive bacteria and some gram-negative cocci, not the specific atypical gram-negative rods causing this infection. *Second generation cephalosporin* - **Second-generation cephalosporins** generally lack sufficient anti-pseudomonal coverage to effectively treat necrotizing otitis externa. - While they offer broader gram-negative coverage than first-generation agents, they are typically not robust enough for severe Pseudomonas infections, especially those involving bone. *Aminoglycosides* - **Aminoglycosides** are potent against Pseudomonas aeruginosa but are generally administered parenterally and are associated with significant **ototoxicity** and **nephrotoxicity**. - While effective, their side effect profile and the availability of equally effective and safer oral options like ciprofloxacin make them less favorable as a first-line monotherapy for NOE.
Question 8: Which of the following associations is true regarding facial nerve palsy in temporal bone fractures?
- A. Common with longitudinal fractures
- B. Common with transverse fractures (Correct Answer)
- C. Always associated with CSF otorrhea
- D. Facial nerve injury is always complete
Explanation: **Explanation:** Temporal bone fractures are classically categorized based on their orientation relative to the long axis of the petrous part of the temporal bone. Understanding the anatomical path of the facial nerve is key to predicting injury patterns. * **Why Option B is Correct:** **Transverse fractures** (occurring perpendicular to the petrous ridge) are far more likely to involve the facial nerve. Although they account for only 20% of all temporal bone fractures, they result in facial nerve palsy in approximately **50% of cases**. This is because the fracture line often crosses the internal auditory canal or the fallopian canal directly. * **Why Option A is Incorrect:** **Longitudinal fractures** are the most common type (80%), but they involve the facial nerve in only about **15-20% of cases**. The injury here is usually due to edema or compression rather than direct transection. * **Why Option C is Incorrect:** While CSF otorrhea can occur in longitudinal fractures (due to tympanic membrane rupture), transverse fractures more commonly present with **CSF rhinorrhea** (as the CSF leaks through the Eustachian tube) or a hemotympanum with an intact drum. It is not an "always" association. * **Why Option D is Incorrect:** Facial nerve injury can be **incomplete (paresis)** or **complete (paralysis)**. In longitudinal fractures, the palsy is often delayed and incomplete, whereas in transverse fractures, it is more likely to be immediate and complete. **High-Yield Clinical Pearls for NEET-PG:** 1. **Most common site of injury:** The **Geniculate Ganglion** (Perigeniculate area) is the most frequent site of facial nerve injury in temporal bone trauma. 2. **Management:** Immediate-onset complete paralysis usually indicates nerve transection (requires surgical exploration); delayed-onset palsy suggests edema (managed conservatively with steroids). 3. **Hearing Loss:** Longitudinal fractures are associated with **conductive hearing loss** (ossicular disruption), while transverse fractures cause **sensorineural hearing loss** (labyrinthine involvement).
Question 9: All of the following are true about transverse fractures of the temporal bone EXCEPT:
- A. Facial nerve is commonly involved
- B. Sensorineural deafness can occur
- C. Conductive deafness can occur (Correct Answer)
- D. These fractures are less common
Explanation: Temporal bone fractures are traditionally classified into **Longitudinal** and **Transverse** based on their relationship to the long axis of the petrous pyramid. ### Why Option C is the Correct Answer (The "EXCEPT") Transverse fractures run perpendicular to the petrous ridge, typically crossing the internal auditory canal or the bony labyrinth (cochlea/vestibule). Because the fracture line directly destroys the inner ear structures or the vestibulocochlear nerve, it results in **Sensorineural Hearing Loss (SNHL)**. Conductive hearing loss is characteristic of *longitudinal* fractures, where the tympanic membrane or ossicular chain is disrupted, but the inner ear is spared. ### Analysis of Incorrect Options * **A. Facial nerve is commonly involved:** True. The facial nerve is injured in approximately **50%** of transverse fractures (compared to only 20% in longitudinal). The injury is often a complete transection. * **B. Sensorineural deafness can occur:** True. As the fracture line traverses the otic capsule, it causes permanent, often profound, SNHL and severe vertigo/nystagmus. * **D. These fractures are less common:** True. Transverse fractures account for only **20%** of temporal bone fractures, usually resulting from severe frontal or occipital blows. Longitudinal fractures are more common (80%). ### High-Yield Clinical Pearls for NEET-PG | Feature | Longitudinal Fracture (80%) | Transverse Fracture (20%) | | :--- | :--- | :--- | | **Mechanism** | Lateral blow (Temporal) | Frontal/Occipital blow | | **Hearing Loss** | **Conductive** (Common) | **Sensorineural** (Common) | | **Facial Nerve** | 20% (Delayed/Neuropraxia) | **50%** (Immediate/Transection) | | **Bleeding** | Bleeding from Ear (Tear in TM) | **Hemotympanum** (Intact TM) | | **CSF Leak** | CSF Otorrhea | CSF Rhinorrhea (via Eustachian tube) |
Question 10: A patient with a sinus infection develops chemosis, bilateral proptosis, and fever. What is the most likely diagnosis?
- A. Lateral sinus thrombosis
- B. Frontal lobe abscess
- C. Cavernous sinus thrombosis (Correct Answer)
- D. Meningitis
Explanation: **Explanation:** The clinical triad of **chemosis (conjunctival edema), bilateral proptosis, and fever** following a sinus infection is the classic presentation of **Cavernous Sinus Thrombosis (CST)**. **1. Why Cavernous Sinus Thrombosis is correct:** The cavernous sinuses are paired venous structures located on either side of the sella turcica. They receive venous drainage from the face (via the ophthalmic veins) and the paranasal sinuses (ethmoid and sphenoid). An infection in these areas can lead to septic thrombosis. * **Proptosis and Chemosis:** Occur due to impaired venous drainage from the orbit. * **Bilateral Involvement:** This is the hallmark of CST. Because the two cavernous sinuses communicate via the intercavernous sinuses, an infection starting on one side rapidly spreads to the other. **2. Why other options are incorrect:** * **Lateral Sinus Thrombosis:** Usually a complication of chronic suppurative otitis media (CSOM). It presents with "Griesinger's sign" (edema over the mastoid) and a "picket-fence" fever, but not proptosis or chemosis. * **Frontal Lobe Abscess:** Presents with features of raised intracranial pressure (headache, vomiting, papilledema) and altered mental status, but lacks the specific orbital signs seen here. * **Meningitis:** Presents with fever, neck stiffness, and photophobia. While it can coexist with CST, it does not explain the mechanical orbital findings (proptosis). **Clinical Pearls for NEET-PG:** * **Nerves involved:** Cranial nerves III, IV, V1, V2, and VI pass through the cavernous sinus. **CN VI (Abducens)** is usually the first to be affected (lateral rectus palsy). * **Danger area of the face:** Infections here (e.g., furuncles) can lead to CST due to the **valveless** nature of the facial and ophthalmic veins. * **Treatment:** High-dose intravenous antibiotics and management of the primary source (sinus drainage).
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