Resolving AOM

A 2-year-old male was brought to the emergency department (ED) by his parents because of a fever and a recent diagnosis of an ear infection. The child had developed a runny nose four days prior and was seen by his primary physician who diagnosed a left ear acute otitis media (AOM). This was the child’s first ear infection, and he was placed on antibiotics with instructions to follow up if he continued to have fever or ear pain. His parents stated he had felt warm that evening and had a temporal temperature of 100.9^oF. In the ED, the child was afebrile with age-appropriate vital signs. He has mild clear rhinorrhea. His Wispr digital otoscopic exam is shown.

Which of the following is true regarding the child’s Wispr digital otoscope findings?

A. The tympanic membrane (TM) is normal, and all antibiotics should be discontinued
B. The TM is mild to moderately bulging, and the current antibiotic should be continued
C. The TM is severely bulging, and antibiotics should be changed
D. The child needs an urgent referral to otolaryngology (ENT) for ear tubes

Answer: B. The TM is mild to moderately bulging, and the current antibiotic should be continued

As discussed in previous WiscMed cases, recognizing bulging is an important diagnostic skill given its significance in diagnosing AOM. Since bulging occurs on a continuum, there is clinician subjectivity when determining the degree of bulging. Severe bulging is typically the easiest to identify by its “angry donut” appearance. Mild bulging is often described as “fullness” with the malleus visible but obscured. Moderate bulging represents the wider continuum between the two with a progressive deepening of the central umbo attachment and further loss of all malleus visibility.

This child’s TM fits best into that middle ground of moderate bulging—no malleus is visible, but the bulging is not quite to the donut severity. Recall, the American Academy of Pediatrics practice guideline recommends diagnosing AOM if the TM has moderate/severe bulging. Given this, it would be reasonable to consider this child’s AOM to have failed initial treatment and change him to alternative therapy.  However, close inspection of the TM image provides a clue suggesting a resolving AOM. Note the TM has a patchy appearance with “thicker” pink projections interspersed among “thinner” translucent areas (see annotated image). These likely represent the early stages of mucopurulent patches observed in resolving AOM. This progression can be seen in a previously reported series of images obtained from day 0 through Day 28 of treated AOM.  Thus, while bulging remains the most sensitive indicator of inflammation of the TM and middle ear space, subtle findings such as patchiness and shagrination (Shagrination Case) can help minimize the pitfalls leading to AOM over-diagnosis.

Key Learning Points

1. Acute otitis media (AOM) is diagnosed when bulging of the eardrum is observed.
2. Full resolution of AOM (receding bulging and clearing of the tympanic membrane) can take a month.
3. The presence of patches on the middle ear surface of the TM likely heralds resolving AOM even in the presence of bulging.