Benda Asing Telinga

01Pathophysiology

The external auditory canal is a blind-ending tube approximately 2.5 cm in length in adults, with a lateral cartilaginous portion and a medial bony portion. The canal narrows at the isthmus, the junction between these two segments. Foreign bodies tend to lodge at or medial to this isthmus, which is why deeper objects are harder to retrieve and carry higher risk of complications.

When a foreign body sits in the canal, it causes mechanical obstruction. This produces conductive hearing loss by preventing sound wave transmission to the tympanic membrane (TM). Prolonged contact with the canal wall leads to local mucosal irritation, causing pain, edema, and eventually secondary otitis externa with purulent discharge. This is why a child presenting with unilateral foul-smelling otorrhea that does not respond to standard otic antibiotic drops should raise suspicion for a retained foreign body.

Hygroscopic organic materials (beans, seeds, sponge) deserve special attention because they absorb moisture from the canal and swell over time, making delayed removal progressively more difficult and painful. This is also why irrigation is contraindicated for organic foreign bodies, as the water causes further expansion.

Button batteries represent a true emergency. When a battery contacts the moist canal mucosa, it creates a low-voltage circuit that generates sodium hydroxide (alkaline burns) through electrolysis. This can cause liquefactive necrosis of the canal skin and even erode into deeper structures within hours. The mechanism is the same as esophageal button battery injury: tissue destruction occurs from the alkaline external discharge, not from acid leakage.

Live insects cause intense distress due to movement and buzzing against the TM. The first step is to immobilize the insect by instilling mineral oil, lidocaine, or alcohol into the canal before attempting removal, because a live insect will move deeper and cause TM injury if grasped directly.

02Classification and Clinical Manifestation

03Diagnostic Workup

Otoscopy is the cornerstone. In most cases, the diagnosis is made and confirmed in the same step by directly visualizing the object within the canal. No imaging is needed if the object is clearly seen and the TM is intact.

Imaging becomes necessary when the object cannot be visualized (deep impaction or significant canal edema obscuring the view), when there is concern for TM perforation (sudden onset of vertigo, sensorineural hearing loss, or bloody otorrhea after manipulation), or when a button battery has been present for an uncertain duration and you need to assess the extent of tissue damage.

A key clinical point: if the patient presents with unilateral conductive hearing loss, foul-smelling discharge, and failed treatment for otitis externa, always re-examine with good visualization. A retained foreign body is a classic cause of "treatment-resistant" unilateral otitis externa in children.

04Management and Treatment

Step-by-Step Management Logic

Step 1: Assess urgency. Button batteries and live insects are the two scenarios requiring immediate action. Everything else can be approached in a controlled, elective manner.

Step 2: Choose the technique based on object characteristics. The most commonly tested principle is that round, smooth objects should not be grasped with forceps because the instrument tends to push them medially toward the TM. Instead, a right-angle hook or ear curette is passed lateral to the object and then pulled outward. Irregular objects with edges that can be grasped are appropriate for alligator forceps.

Step 3: Irrigation considerations. Irrigation with warm (body-temperature) water using a syringe is effective for small, non-organic debris and cerumen. It is contraindicated in three situations: (1) suspected TM perforation, (2) organic foreign bodies, and (3) button batteries. Using cold or hot water can cause caloric-induced vertigo and nystagmus, so always use water at body temperature.

Step 4: Post-removal care. After removal, perform otoscopy again to confirm the canal is clear and the TM is intact. If there is canal abrasion or secondary infection, prescribe otic antibiotic drops (e.g., ofloxacin otic or ciprofloxacin/dexamethasone drops) for 5-7 days. If TM perforation is identified, use non-ototoxic drops (fluoroquinolone-based) and refer to ENT for follow-up.

Step 5: Know when to stop. If the first or second attempt at removal fails, or the patient (especially a child) is uncooperative, stop and refer to ENT. Repeated blind attempts cause canal edema, bleeding, and can convert a simple foreign body into a complicated one requiring anesthesia.

05Differential Diagnosis and Distractors

06Traps and High-Yield Pearls

The most common way students lose points on this topic is by selecting irrigation as the removal method for every foreign body type. Irrigation is a reasonable technique for many inorganic objects, but choosing it for organic/hygroscopic material, button batteries, or in the setting of a perforated TM is a classic wrong answer on the exam.

The second major trap involves button batteries. A vignette describing a child with rapidly worsening ear pain and dark or bloody discharge after placing a "small disc" in the ear canal is testing whether you recognize the urgency. The correct answer is always emergent removal, not observation, not irrigation, not topical antibiotics. Any delay risks permanent canal stenosis or deeper structural damage.

For live insects, the tested concept is sequence: immobilize first, then remove. Jumping directly to forceps extraction is wrong because the insect will burrow deeper and potentially perforate the TM.

Finally, remember the "rule of attempts": if you cannot remove the object after one or two careful tries, the next best step is ENT referral, not continued attempts. The vignette may describe a child who is crying and uncooperative after a failed attempt, and the tested answer is procedural sedation or referral, not "try again with a different instrument."

The core competency being tested across all ear foreign body questions is matching the correct removal technique to the object type and recognizing the two emergencies (button battery and live insect) that change the standard approach.