B Viswanatha, R Dutta, R Anilkunar, D Sumatha
external ear canal, foreign body, migration, post aural area
B Viswanatha, R Dutta, R Anilkunar, D Sumatha. Migration of a foreign body from post aural area to the external ear canal. The Internet Journal of Otorhinolaryngology. 2008 Volume 10 Number 2.
A 34 year old male patient presented with left ear discharge and ear pain of one month duration. Otomicroscopic examination showed an edematous ear canal and a hard mass was present in the left ear canal. A horizontal scar was present in the post aural area and it was due to an accident. A glass piece was removed through post aural route. This glass piece had entered into the post aural area at the time of accident and later migrated into the external ear canal. At the fourth week of follow-up ear canal was normal and patient was symptom free.
Foreign bodies in the external ear canal are common and some times challenging problem .Ear foreign bodies are commonly seen in children. Presence of inanimate foreign body in the ear of an adult patient without his knowledge is very rare . Migration of a foreign body from post aural ear into the external ear canal is not reported in the literature.
A 34 year old male patient came with complaints of left ear discharge and ear pain of one month duration. It was insidious in onset. Discharge and pain started together. Discharge was yellowish, intermittent and small in quantity. It was associated with mild continuous ear pain.
On examination left ear canal was edematous (figure 1). A horizontal scar was seen in the left post aural area near the tip of the mastoid area (figure 2).
This was due to an accident which he had six months back and had a lacerated wound in the left post aural area. Following the accident, the patient did not have any ear problem and at that time ear examination was normal.
Otomicroscopic examination showed mucopurulent discharge and an impacted hard mass in left ear canal. Granulations were present over the posterior canal wall. Under local anaethesia, ear canal was opened through post aural route. A triangular piece of glass measuring 3 cm in length was seen in the outer ear canal
It was impacted firmly at the isthmus and it was removed carefully. Tympanic membrane was normal. At the fourth week of follow-up the ear canal was normal and the patient was symptom free.
Foreign bodies in the external ear canal are most commonly seen in children. The foreign bodies found most commonly in the ear are cotton wool, insects, beads, paper, small toys and eraser. In adults, commonly seen foreign bodies are live insects, cotton wool and broken match stick which are used to clear or scratch the ear canal .In a study on adult aural foreign bodies, Ryan et al  found that the most frequently seen foreign body in adults was cotton wool. Bressler et al  reported that the cockroaches are the common foreign bodies seen in the external ear canal.
The diagnosis of external ear canal foreign body is straight forward and does not need any special investigation .In the present case also patient had otitis externa due to a foreign body and did not require any special investigation.
Firmly impacted foreign bodies medial to the isthmus, requires surgical removal. A post auricular approach and widening of ear canal by bone drill is advised . In the present case also foreign body was impacted and it was removed through the post aural route.
Complications may be caused by the action of introducing foreign bodies or the foreign bodies itself. These include laceration of the canal skin and otitis externa, facial palsy, tympanic membrane perforation and ossicular chain damage .In the present case patient had otitis externa as a result of foreign body in the external ear canal.
Occasionally a foreign body inner ear damage, either through subluxation of the stapes and disruption of the oval window integrity or through trauma to the round window region .
There are reports of foreign body migration from one anatomical area to the other [7, 8]. But there is no report of foreign body migration into the external ear canal. In the present case glass piece had entered into the post aural area at time of an accident. As the wound was sutured at that time, it remained inside. It was asymptomatic for a long time. Later it migrated into the external ear canal.