A Bezold abscess occurs when the medial bony wall of the mastoid tip, which is typically thin in individuals with well-developed mastoid air cells, is eroded due to mastoid empyema. Pus breaks through this area and tracks deep to the sternocleidomastoid muscle, forming an abscess on the lateral side of the neck.
Clinical manifestations
A prior history of middle ear infection or middle ear cholesteatoma is commonly present.
Pain in the ipsilateral neck with restricted neck movement is present. Swelling and tenderness in the neck correspond typically to the mastoid tip and the mandibular angle. Due to the deep location of the abscess beneath the sternocleidomastoid muscle, undulation is usually not apparent.
Aspiration of purulent fluid confirms the diagnosis.
If the infection spreads downward, it may lead to mediastinitis or a mediastinal abscess.
Differential diagnosis
This condition should be differentiated from Mouret abscess, which results from erosion of the mastoid tip at the digastric groove. In Mouret abscess, inflammatory exudate extends along the digastric muscle to the parapharyngeal space, forming a deep cervical abscess.
Treatment
During mastoidectomy, residual air cells and pathological tissue in the mastoid tip should be removed completely.
Incision and drainage of the abscess through an anterior margin approach to the sternocleidomastoid muscle should be performed early.