Recall:
A 3-year-old boy is brought to the Emergency Department by his father. He has been irritable for the past 24 hours and has a high-grade fever. His father notes that the child had a “cold and earache” last week which seemed to be improving. On examination, the child is febrile 38.9. There is noticeable erythema and fluctuant swelling behind the right pinna, causing the pinna to be displaced anteriorly and downwards. The tympanic membrane is dull and bulging.
What is the most likely diagnosis?
A. Atypical mycobacterial adenitis
B. Eczema herpeticum
C. Mastoiditis
D. Non-accidental injury (NAI)
E. Mumps
F. TB adenitis
Correct Answer: C. Mastoiditis
Clinical Explanation
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Clinical Presentation: Mastoiditis is a common complication of untreated or severe Acute Otitis Media (AOM). The classic signs—which you should look for in exam stems—are fever, irritability, and post-auricular swelling that results in the protrusion of the pinna (forward and downward displacement).
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Pathophysiology: The infection spreads from the middle ear to the mastoid air cells, potentially leading to bone destruction and abscess formation.
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Management: This is a clinical emergency requiring admission for intravenous antibiotics and sometimes surgical drainage (myringotomy).
Exam Pearl
Mastoiditis
Acute mastoiditis is rare and is usually caused by infection spreading from the middle ear. Consequently, the responsible organisms are commonly those causing an acute OM. Young children can present with fever, pain in or behind the ear and localised swelling and tenderness over the mastoid bone which displaces the pinna forward and inferiorly. The swelling is tender and may be fluctuant.
Cranial imaging with contrast CT should be considered in the presence of focal neurological signs, reduction in conscious level or prior to a general anaesthetic to drain the mastoid abscess. Treatment requires intravenous antibiotics and an early ENT review to clarify whether mastoidectomy would be indicated.
