Bezold's abscess

Bezold Abscess is a rare deep neck abscess resulting from an intertemporal complication of a coalescent mastoiditis. It was first described by a German Otologist Dr. Friedrich Bezold in 1881. Since the introduction of antibiotics, the number of reported cases of Bezold abscesses have significantly decreased. According to some authors, since 1967 there have been only 35 reported cases in the English literature, of which only four cases occurred in children under the age of five.

Etiology:

The organisms commonly cultured from Bezold abscesses include gram-positive aerobes: Streptococcus, Staphylococcus, and Enterococcus species; gram-negative aerobes: Klebsiella, Pseudomonas, and Proteus species and anaerobes, particularly Peptostreptococcus and Fusobacterium species.

Epidemiology:

Many factors have been shown to play a role in the development of acute, chronic, and suppurative otitis media in children. Factors include the following:

Socioeconomic conditions: there is an increase in the number of the cases in children living in poorer socioeconomic conditions.

Daycare: there appears to be an increase in children attending day care.

Underlying medical conditions that affect the Eustachian tube function: children with cleft palate, craniofacial anomalies, congenital or acquired immune dysfunction, conditions affecting the ciliary function of the Eustachian tube and middle ear mucosa.

In adults, medical considerations that must be considered are the patient HIV status, history of uncontrolled diabetes, renal failure, and patients who are immunosuppressed.

Pathophysiology:

The most important contributing factor in the development of a Bezold abscess is the presence of a well-aerated and pneumatized mastoid bone. At birth, the mastoid bone consists mainly of an antral cell. From this antral cell, air cells begin to develop until there is complete pneumatization of the mastoid bone around the age of five. As the process of pneumatization of the mastoid bone occurs, the surrounding walls of the mastoid bone thin, particularly at the tip of the mastoid bone on its medial surface along the incisura digastrica (digastric groove) where the digastric muscle attaches. If the infection is left unchecked, the outer walls of the mastoid tip become involved with the spread of the infection along the sternocleidomastoid muscle, the trapezius, and splenius capitis muscles. Secretions and bacteria can enter the middle ear through the eustachian tube and from the middle ear can pass directly into the mastoid bone through a small opening the aditus ad antrum. During an inflammatory process (suppurative otitis media), obstruction of the aditus ad antrum occurs. Purulent secretions cannot escape and will accumulate in the mastoid bone. The pressure created by this purulent material with its enzymatic activity within the mastoid bone causes osteitis and osteonecrosis of the fragile pneumatized air cells further thinning the walls of the mastoid bone. This stage is Coalescent Mastoiditis. The inflammatory process can spread in many directions. If it spreads inferiorly towards the mastoid tip, the purulent material will eventually erode the very thin bone along the digastric ridge at the insertion of the digastric muscle. Consequently, a purulent material will spread into the neck between the digastric and sternocleidomastoid muscles.

Clinical features:

Bezold abscess may occur in both children and adults with well-developed mastoid bones. Both may have had a history of recurrent otitis media or chronic otitis media with tympanic membrane perforation and a draining ear. Prior mastoid surgery for cholesteatoma normally causes further thinning of the mastoid walls making it easier for infection to spread. An important early clinical sign of a coalescent mastoiditis on physical examination is sagging of the posterior superior external auditory canal. Other common clinical signs include the following:

neck pain

swelling in the lateral neck

post auricular tenderness over the affected mastoid bone

otalgia

otorrhea

hearing loss

If any of the above are documented, and the patient presents with fever with an associated neck mass one should have a high index of suspicion that the infection has spread to adjacent regions within the head and neck. Thus a thorough head and neck evaluation should always be conducted. In the differential diagnosis, one must always consider an abscess of post-auricular lymph nodes. If CT scanning is not available, then a simple lateral x-ray of the temporal bone may be helpful in ascertaining the status of the mastoid air cell system.

Evaluation:

Laboratory evaluations are often not helpful since the leukocyte count and erythrocyte sedimentation rate may be normal. Contrast computed tomography should be obtained if there is any indication or suspicion of a deep neck abscess, regardless of a lack of evidence of an infection in the mastoid bone since prior antibiotics may have truncated the infection in the mastoid bone while the abscess was still developing in the neck. Recently, in the emergency room setting, a bedside soft-tissue ultrasound with the use of a high-frequency linear array probe to the mastoid was used to detect a complex hypoechoic-anechoic fluid collection in the neck. An intravenous contrast CT scan was used to confirm the ultrasound findings, and both an abscess in the neck and ear pathology were identified.

Treatment:

If a Bezold abscess is present or suspected, practitioners should use intravenous broad-spectrum antibiotics. Once antibiotic therapy is initiated, a contrast CT scan should be obtained. Naturally, cultures are important, particularly if you are dealing with a diabetic or immunocompromised patient since the bacteriology in these cases may be different. If surgical management is indicated, in adults, a post-auricular incision is made, and a simple, complete mastoidectomy should be performed. The objective is to remove as much osteitic bone and granulation tissue present in the mastoid bone. In rare cases, a Bezold abscess may appear in children before there is a complete development of the mastoid air cell system. In these patients, the practitioner must pay particular attention to the position of the facial nerve. Therefore, they should not make a standard post-auricular incision since the facial nerve may be more superficial than anticipated. In this case, a post-auricular superior linear incision is made to drain the purulent material and carefully debride as much granulation tissue as possible. At the same time, the neck abscess should be thoroughly drained. Broad-Spectrum antibiotics should be continued until a final resolution is obtained to prevent further extension of the inflammatory process to adjacent vascular structures