Hereditary or genetic factors influence the degree of pneumatisation as demonstrated by Schwarz, Dahlberg and Diamant. The angulation at the base of the skull interferes with the anatomical position and patency of the Eustachian tube

and leads to impaired pneumatisation of the mastoid.

What bacteria causes mastoiditis?

The most common are Streptococcus pneumoniae and Pseudomonas aeruginosa, as well as Staphylococcus aureus and nontypeable Haemophilus influenzae. Anaerobic organisms may also cause mastoiditis. However, the prevalence of bacterial organisms may be dependent on age and location.

How do they test for mastoiditis?

Diagnosis of mastoiditis begins with an examination of the ear. Tests that may be used to confirm a diagnosis include CT scan, MRI, X-ray, blood tests, fluid culture, hearing test, and lumbar puncture or “spinal tap.”