Otitis Externa — MCQs
Which of the following drugs can cause ototoxicity?
Which of the following statements about tubercular otitis media is false?
Which of the following is the LEAST likely risk factor for developing acute otitis externa?
A 60-year-old diabetic presents with otalgia, otorrhea, and granulation tissue in EAC. Empiric treatment should include:
A 40-year-old woman presents with a three-day history of irritation, pain, and watery discharge from her left ear. She has recently returned from a holiday, during which she used her towel, artificial nails, and earbuds to alleviate itching in her ear. What is the likely diagnosis?
What is the causative agent for malignant otitis externa?
Most common cause of otitis externa is
A patient presented with the following picture of Tympanic Membrane. Most Probable diagnosis (marked with arrow):
A patient has a foul-smelling ear discharge and a polyp seen in the middle ear. What is the likely diagnosis?
A 35-year-old patient presents with hearing loss and discomfort in the right ear. Examination reveals keratin accumulation in the ear canal. What is the most likely diagnosis?
Otitis Externa Indian Medical PG Practice Questions and MCQs
Question 1: Which of the following drugs can cause ototoxicity?
- A. Metronidazole
- B. Amoxicillin
- C. Ciprofloxacin
- D. Amikacin (Correct Answer)
Explanation: ***Amikacin*** - **Amikacin** is an **aminoglycoside antibiotic** and is **the most well-known** drug among the options for causing **ototoxicity** (damage to the ear, leading to hearing loss, tinnitus, or vestibular dysfunction) [1], [2]. - This adverse effect is **dose-dependent** and related to the **cumulative dose** and **peak plasma levels** of the drug [2]. - Aminoglycosides cause both **cochlear toxicity** (hearing loss) and **vestibular toxicity** (balance problems) [1], [2]. *Metronidazole* - **Metronidazole** is an antibiotic and antiprotozoal drug that primarily causes **gastrointestinal upset** and a **metallic taste** in the mouth. - While it can cause neurological side effects like **peripheral neuropathy**, **ototoxicity is not a typical adverse effect** associated with metronidazole. *Amoxicillin* - **Amoxicillin** is a common **penicillin-class antibiotic** generally considered safe with a good side effect profile. - Its most common side effects are **gastrointestinal disturbances** like nausea, vomiting, and diarrhea, as well as **allergic reactions** and skin rashes. - **Ototoxicity is not a recognized side effect** of beta-lactam antibiotics. *Ciprofloxacin* - **Ciprofloxacin** is a **fluoroquinolone antibiotic** primarily associated with side effects like **tendinopathy**, **arthropathy**, and **QT prolongation**. - While fluoroquinolones **can cause ototoxicity** (tinnitus, hearing disturbances), this is **much less common and less severe** compared to aminoglycosides. - Ciprofloxacin is not the primary drug associated with ototoxicity in this context.
Question 2: Which of the following statements about tubercular otitis media is false?
- A. Spreads through the eustachian tube
- B. Usually affects only one ear
- C. Causes painful ear discharge (Correct Answer)
- D. May cause multiple perforations
Explanation: ***Causes painful ear discharge*** - **Pain** is typically an **absent or minimal symptom** in tubercular otitis media, even with significant ear discharge. - The discharge is usually **thin, watery, and non-purulent**, reflecting the indolent nature of the infection. *Spreads through the eustachian tube* - Tubercular otitis media can spread via the **eustachian tube** from the nasopharynx, especially in cases of active pulmonary or pharyngeal tuberculosis. - This is a common route for infectious agents to reach the middle ear. *Usually affects only one ear* - Tubercular otitis media predominantly presents as a **unilateral infection**. - While bilateral involvement can occur, it is less common than unilateral presentation. *May cause multiple perforations* - Tubercular otitis media is notorious for causing **multiple, small perforations** in the tympanic membrane. - This feature, often described as a "sieve-like" drum, is a characteristic diagnostic clue for the condition.
Question 3: Which of the following is the LEAST likely risk factor for developing acute otitis externa?
- A. Presbycusis (Correct Answer)
- B. Tympanic membrane perforation
- C. Frequent swimming
- D. Use of hearing aids
Explanation: ***Presbycusis*** - **Presbycusis** is age-related sensorineural hearing loss affecting the **inner ear (cochlea)** and auditory nerve pathways - It is a **degenerative condition** with NO involvement of the external auditory canal - There is **no pathophysiological mechanism** linking presbycusis to acute otitis externa, as it does not affect the ear canal's skin barrier, moisture balance, or susceptibility to infection - This is the **LEAST likely** risk factor among the options *Frequent swimming* - **Major risk factor** for acute otitis externa ("swimmer's ear") - Water exposure washes away protective **cerumen** and increases canal pH - Creates a **moist environment** ideal for bacterial proliferation, especially ***Pseudomonas aeruginosa*** and *Staphylococcus aureus* - Maceration of canal skin compromises the natural barrier *Use of hearing aids* - **Well-documented risk factor** for otitis externa - Hearing aids **occlude the ear canal**, trapping moisture and debris - Can cause **mechanical trauma** to the delicate canal skin - Creates a warm, humid environment promoting bacterial and fungal growth - Regular users are at increased risk, especially with poor hygiene *Tympanic membrane perforation* - While primarily associated with **chronic otitis media**, a perforation can predispose to external canal complications - May allow **moisture entry** and middle ear drainage into the canal - However, the direct risk for acute otitis externa is less significant compared to factors that directly affect the external canal environment - Still more relevant than presbycusis, which has no connection to the external ear
Question 4: 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 5: A 40-year-old woman presents with a three-day history of irritation, pain, and watery discharge from her left ear. She has recently returned from a holiday, during which she used her towel, artificial nails, and earbuds to alleviate itching in her ear. What is the likely diagnosis?
- A. Mastoiditis
- B. Otitis Externa (Correct Answer)
- C. ASOM
- D. Trigeminal Neuralgia
Explanation: ***Otitis Externa*** - The patient's history of manipulating her ear with foreign objects like **artificial nails** and **earbuds**, especially when combined with a recent holiday (often involving swimming), strongly suggests **otitis externa**. - Symptoms such as **irritation, pain**, and **watery discharge** localized to the external ear canal are classic presentations, often exacerbated by a breach in the protective **skin barrier** of the canal. *Mastoiditis* - This is an **infection of the mastoid bone** behind the ear, typically presenting with postauricular pain, swelling, and fever. - It usually occurs as a complication of **untreated acute otitis media**, which is not indicated by the patient's symptoms or history. *ASOM* - **Acute Suppurative Otitis Media (ASOM)** involves **middle ear infection**, characterized by ear pain, fever, and a bulging **tympanic membrane**. - The symptoms described are more consistent with an external ear canal issue, and there is no mention of systemic symptoms or significant middle ear involvement. *Trigeminal Neuralgia* - This condition involves **severe, sudden, shock-like facial pain** along the distribution of the trigeminal nerve. - It does not cause ear discharge, irritation, or persistent ear pain that would be associated with local trauma or infection.
Question 6: What is the causative agent for malignant otitis externa?
- A. Streptococcus
- B. Staphylococcus aureus
- C. Influenza
- D. Pseudomonas (Correct Answer)
Explanation: ***Pseudomonas*** - **Malignant otitis externa** is a severe, rapidly progressive infection of the external auditory canal and skull base, primarily caused by **Pseudomonas aeruginosa**. - This opportunistic bacterium thrives in moist environments and commonly affects immunocompromised individuals, such as diabetics or the elderly. *Streptococcus* - While various *Streptococcus* species can cause common ear infections (e.g., **otitis media**), they are not the primary causative agent for malignant otitis externa. - Infections by *Streptococcus* typically present differently and affect other parts of the ear or body more commonly. *Staphylococcus aureus* - **Staphylococcus aureus** is a common cause of skin infections, including localized forms of otitis externa (e.g., furuncles), but it is rarely implicated in the aggressive, invasive form known as malignant otitis externa. - When *Staphylococcus aureus* is involved, it often presents differently and is less likely to cause skull base osteomyelitis. *Influenza* - **Influenza** is a viral infection primarily affecting the **respiratory system** and is not a bacterial pathogen responsible for otitis externa, malignant or otherwise. - Viral infections like influenza can predispose individuals to secondary bacterial infections, but they are not directly causative of this condition.
Question 7: Most common cause of otitis externa is
- A. Fungal infection
- B. Bacterial infection (Correct Answer)
- C. Seborrheic disease
- D. Herpes Zoster
Explanation: ***Bacterial infection*** - The most common pathogens causing **otitis externa** are bacteria, primarily **Pseudomonas aeruginosa** and **Staphylococcus aureus**. - This condition, often called "swimmer's ear," is favored by moisture in the ear canal, which creates a conducive environment for bacterial growth. *Fungal infection* - While fungal infections (otomycosis) can cause otitis externa, they are **less common** than bacterial causes. - Fungi like *Aspergillus* and *Candida* are typically involved, often in immunocompromised individuals or after prolonged antibiotic use. *Seborrheic disease* - **Seborrheic dermatitis** can affect the ear canal and surrounding skin, leading to flaking, itching, and inflammation. - However, it is a primary skin condition and does not directly cause infectious otitis externa, although it can predispose to secondary infections. *Herpes Zoster* - **Herpes zoster oticus** (Ramsay Hunt syndrome) is a viral infection affecting the facial nerve, causing a painful rash, facial paralysis, and hearing loss. - It is a specific viral etiology with distinct neurological symptoms and is not a common cause of general otitis externa.
Question 8: A patient presented with the following picture of Tympanic Membrane. Most Probable diagnosis (marked with arrow):
- A. Tubercular Otitis Media (Correct Answer)
- B. Syphilitic Otitis Media
- C. Pseudomonas infection
- D. Fungal Otitis Media
Explanation: ***Tubercular Otitis Media*** - The image exhibits **multiple perforations** in the tympanic membrane, along with **pale granulation tissue**, which are classic clinical features of **tubercular otitis media**. - Tubercular ear infections often present insidiously with **painless otorrhea** and **progressive hearing loss**, eventually leading to multiple perforations as the disease advances. *Syphilitic Otitis Media* - Syphilitic otitis media typically presents as **sensorineural hearing loss**, often sudden, and can be associated with **vestibular symptoms**. - It usually does **not cause multiple perforations** or extensive granulation tissue in the tympanic membrane. *Pseudomonas infection* - **Pseudomonas otitis externa** commonly causes severe pain, swelling, and purulent discharge, often seen in _elderly diabetic_ or _immunocompromised_ patients with potentially **malignant otitis externa**. - While *Pseudomonas* can cause chronic suppurative otitis media (CSOM) with a perforation, it doesn't typically lead to **multiple perforations** in the manner depicted. *Fungal Otitis Media* - Fungal otitis media (otomycosis) is characterized by the presence of **black, white, or yellow fungal debris** and hyphae within the external ear canal and on the tympanic membrane. - While it can cause inflammation and sometimes perforation, the image does not show characteristic **fungal elements** or the extensive **granulation tissue** typical of tubercular disease.
Question 9: A patient has a foul-smelling ear discharge and a polyp seen in the middle ear. What is the likely diagnosis?
- A. Chronic otitis media
- B. Cholesteatoma (Correct Answer)
- C. Otitis externa
- D. Otosclerosis
Explanation: ***Cholesteatoma*** - A **foul-smelling ear discharge** and the presence of an **aural polyp** arising from the middle ear are classic signs of cholesteatoma, an abnormal keratinizing squamous epithelium growth in the middle ear. - Cholesteatomas often erode surrounding bone, leading to complications like hearing loss, vertigo, and facial nerve paralysis if left untreated. - The **foul smell** is characteristic due to the accumulation of keratin debris and secondary infection. *Chronic otitis media* - While chronic otitis media can cause ear discharge, it is typically not described as "foul-smelling" unless there is an associated cholesteatoma or significant secondary infection. - The presence of an **aural polyp** strongly suggests cholesteatoma rather than simple chronic otitis media. *Otitis externa* - **Otitis externa** is an infection of the **external ear canal** and typically presents with pain, itching, and discharge, but does not involve middle ear pathology or aural polyps. - The discharge in otitis externa is generally not foul-smelling in the same way as that associated with cholesteatoma. *Otosclerosis* - **Otosclerosis** is a condition causing **progressive conductive hearing loss** due to abnormal bone growth in the middle ear, specifically around the stapes footplate. - It does not involve ear discharge or the formation of polyps and presents primarily with hearing loss.
Question 10: A 35-year-old patient presents with hearing loss and discomfort in the right ear. Examination reveals keratin accumulation in the ear canal. What is the most likely diagnosis?
- A. Keratosis obturans (Correct Answer)
- B. Exostosis
- C. Cerumen
- D. Otitis externa
Explanation: ***Keratosis obturans*** - This condition is characterized by an **accumulation of desquamated keratin** and epithelial debris in the bony external auditory canal, leading to earache, conductive hearing loss, and sometimes widening of the ear canal. - The patient's presentation of **hearing loss**, **discomfort in the right ear**, and **keratin accumulation** aligns directly with the description of keratosis obturans. *Exostosis* - Exostoses are **bony growths** in the ear canal, often associated with cold water exposure. - While they can cause hearing loss and earwax impaction, they do not involve primary **keratin accumulation** as described. *Cerumen* - **Cerumen** is normal earwax, which is a mix of secretions and desquamated cells. - While excessive cerumen can cause hearing loss, the description of **keratin accumulation** suggests a more organized, dense plug than typical cerumen impaction. *Otitis externa* - **Otitis externa** is an inflammation or infection of the ear canal, presenting with pain, redness, swelling, and discharge. - While it can cause discomfort and sometimes lead to debris, the primary finding is **inflammation**, not specifically a large accumulation of keratin.
Want unlimited practice?
Get full access to all questions, explanations, and performance tracking.
Start For Free