(HealthDay News) -- When the mastoid bone in the skull becomes infected, it's called mastoiditis. Often it's triggered by an infection in the middle ear, and it's most common in children.
The U.S. National Library of Medicine mentions these symptoms that may indicate mastoiditis:
Roll Up Your Sleeve: Flu Shot Season is At Hand
New Flu Strain Weakened This Year’s Vaccine Protection, CDC Says
Flu Season Starts Early in NYC as Cases Rise Fast
The Flu Vaccine Can Lower Your Risk Of Heart Attack And Stroke — Even If You Wind Up Infected
Scientists' Push For a Universal Vaccine Takes a Key Step Forward