What is a common cause of mastoiditis?

• A. Viral infection
• B. Middle ear infection
• C. Head injury
• D. Sinus infection

Answer: (B)

Mastoiditis commonly occurs as a complication of a middle ear infection, also known as otitis media. The mastoid is a bony area located behind the ear that contains air cells, and when bacteria from an infection in the middle ear spread to these air cells, it can lead to inflammation and infection of the mastoid itself. This can happen particularly if the middle ear infection is severe or not adequately treated, allowing pathogens to invade and propagate in the adjacent mastoid area.

The other options—viral infection, head injury, and sinus infection—do not typically lead to mastoiditis in the same direct manner. While a viral infection can certainly affect the ears, it is not a primary cause of mastoiditis. A head injury may lead to various complications, but it is not a common pathway to mastoiditis. Sinus infections can cause other complications, but they are not generally linked to the development of mastoiditis. Thus, the pathway from a middle ear infection to mastoiditis is well established, making this the most accurate choice.