Acute Otomastoiditisin Children: Clinical Presentations and Management

Acute mastoiditis (AC) is a serious complication of acute otitis media (AOM) affecting, in most cases, the pediatric population. Diagnosis is usually easy in front of a retro auricular swelling associated to OM. However, this disease may cause significant and even life threatening complications beyond the tympanomastoid system such as peripheral facial nerve palsy, Bezold’s abscess, meningitis, subperiosteal abscess and brain abscess. Management of AC remains controversial raging from conservative treatment in the form of IV antibiotics to more aggressive interventions such as mastoidectomy. This retrospective study represents our experience in the management of AC in the pediatric population. Our purpose was to review and discuss clinical presentations and main treatment modalities of AM.


Introduction
Acute mastoiditis (AM) is an infectious process which involves the mastoid bone and cavities realizing a real osteitis. 0.24% of acute otitis media (AOM) are complicated by acute AM. Infants and younger children are more concerned by the disease. Although diagnosis is usually evident in front of clinical facts, management, especially mastoidectomy, is still controversial.

Patients and Methods
We retrospectively reviewed the medical data of 62 children suffering from AM, who were admitted in the ENT and cervico facial surgery department of the RABTA hospital of Tunis between the years 1990 and 2013. We included in the study children aged 16 years and younger presenting AM following chronic or acute otitis.

Results
Of the 62 children diagnosed with AM, 35 (56%) were males and 27 (44%) were females (sex ratio= 1.3). The average age was 4 years with a range from 2 months to 14 years. 33% of patients were infants younger than 1 year. In medical history we noted microcytic anemia in one case, intra-uterine growth retardation in another case and one patient having had chemotherapy for malignant tumor of the clavicle. The left mastoid was concerned in 33 cases (53%) while the right side in 29 cases (47%). An interval between 1 and 30 days between initial symptoms and first consultation was found (average delay was 16 days).
In 45 cases (72.5%), a first episode of AOM previous to the AM was found. In the other cases AM was a complication of Cholesteatoma in 9 cases (14.5%) (congenital Cholesteatoma in 3 cases and acquired Cholesteatoma in 6 cases) and simple chronic otitis in 8 cases.
Retro auricular swelling was the chief complaint noted in 61 cases (98%). Otalgia, otorrhea, fever and facial palsy were found respectively in 32, 34, 51 and 2 cases (table 1). In all cases general condition was preserved. Retro auricular swelling which was noted in 62 cases was extended to the neck in 2 patients. It was inflammatory and fluctuant in 36 cases (58%) and limited to a simple mastoid tenderness in the other cases ( Figure 1). Spontaneous cutaneous fistula was noted in 2 children (3.2%).
Retro auricular swelling was found in 97% of cases. When performing otoscopy, several pathological aspects were objectified in external auditory canal in 91% of cases (table 2) and in the tympanic membrane in 95.16%. Tympanic membrane perforation was noted in 12 cases. It was central in 8 cases and marginal with Cholesteatoma in the other 4 cases. One patient in the series had a parotid abscess. The neurological examination found 2 patients with peripheral facial palsy and one patient with clinical presentation suggesting intracranial hypertension.  All patients have benefited of a blood count. Hyperleukocytosis was noted in 84.6% of cases. CRP level was evaluated in 18 cases. It was positive in 10 cases with an average of 45mg/l. 30 patients (49%) have benefited of CT scan of the brain and temporal bone confirming the diagnosis of acute otomastoiditis. Intracranial complications were noted in 2patients. It consisted in extradural and subdural abscesses. In these 2 cases AM followed an episode of AOM. CT scan findings are summarized in table 3. Figure 3 illustrates a retro auricular collection.  Bacteriological samples were performed in 20 patients. Theses samples were positive in 8 cases. Staphylococcus aureus was the most frequent pathogen (5 cases) followed by Streptococcus pneumonia (2 cases) and Proteus Mirabilis in one case.
IV antibiotics were used in all cases. It consisted in a bitherapy in the majority of cases (49 patients). Monotherapy was administrated in 10 cases (Table 4). Patients were divided in 4 groups depending on the management modalities.
Group 1: antibiotics only: 27 patients (43%) were treated by IV antibiotics (7 subperiosteal abscesses and 20petrositities). Treatment was ensured for a period varying from 2 weeks to one month. IV treatment was administrated for 10 days. Mean hospital stay was 8 days.
Group 2: antibiotics associated to flattening of subperiosteal abscess: This group counts 15 patients (24%). Flattening of the abscesses was performed for all patients. Bacteriological samples were systematic. Antibiotic therapy was ensured for a period of 2 weeks to 1 month. IV treatment was administrated for 10 to 15 days. Mean hospital stay was 9 days.
Group 3: antibiotics associated to flattening of subperiosteal abscess and mastoidectomy: This group counts 7 patients. Flattening of the abscess was performed since admission of the child. Mastoidectomy was then done within a time limit from 2 to 11 days with an average of 6 days. Mean hospital stay was 21 days (10 to 43 days).
Group 4: antibiotics associated to mastoidectomy: This group counts 13 patients (21%). Time limit between starting antibiotics administration and mastoidectomy varied from 1 to 20 days with an average of 3 days. Mean hospital stay was 12 days (7 to 30 days).
In the third and fourth group, mastoidectomy was done from the start when AM was associated to Cholesteatoma or in complicated forms (facial palsy, brain abscess). The same intervention was done secondarily when antibiotics (alone or associated to flattening) were not efficient after 48h (table 5). Eight patients underwent a canal wall down mastoidectomy whereas 1 patient underwent a canal wall up mastoidectomy. The facial nerve was bare in its 2 nd portion in one case and in the second genu in another case. Covering by the temporal aponeurosis was performed in both cases. Mastoidectomy was done secondarily in one case after drainage of extradural abscess by neurosurgeons.
Immediate outcome was favorable in 60 cases with ear drying and regression of retro auricular swelling. 2 patients presented wound healing problems that responded well to antibiotic and local care.
Median follow-up was 24 months (2 months to 10 years). 43 patients were seen at the consultation beyond one month. 5 among them presented a relapse of their disease (table 6).

Discussion
AM prevalence has considerably decreased since the wide use of antibiotics. However, a recent increase of the incidence has been reported due to the immergence of resistant pneumococcus strains with decreased sensitivity to Penicillin [1,2]. Young children are more concerned with AM especially between the second and third years of life [1,3]. Middle age in our series was 4 years with incidence peaking in infants younger than 2 years (47.7%). Generally, AM is a complication of AOM [4] it could also follow and infectious episode of Cholesteatoma.
Clinical presentation depends on age and the disease progression [5,6]. retro auricular swelling is a constant sign with an important clinical value. The most reliable otoscopic findings are otorrhea, posterior wall fall and bulging tympanic membrane.
CT scan of temporal bone and brain is the reference investigation for AM diagnosis and complications. According to some authors it should be systematic [3]. For others, it should