Retropharyngeal Abscess with Clival Osteomyelitis Caused by Staphylococcus intermedius and Staphylococcus aureus in a 6-Year-old Boy.

Abstract

To the Editors: In the March 2023 issue of PIDJ, we read a case report of septic arthritis of the atlanto-occipital joint caused by Staphylococcus intermedius, Di Siena, and coworkers. In our hospital, we treated a similar case of a 6-year-old boy with a retropharyngeal abscess and clival osteomyelitis caused by S. intermedius and S. aureus. Our patient was a 6-year-old previously healthy boy. He presented with a low-grade fever (38.3 max.), headaches and torticollis. At a local hospital, computed tomography of the head and neck was performed, and a diagnosis of retropharyngeal abscess was established. The patient was sent to our clinic for additional workup and therapy. His blood count was 8600 L/cmm with a neutrophil predominance of 76%. C-reactive protein was 81.7 mg/L. The rest of the routine biochemical tests were unremarkable. The throat swab test results were negative. Two sets of blood cultures taken before antimicrobial therapy were sterile. We consulted an otolaryngology specialist who performed an adenoidectomy with incision and drainage of the retropharyngeal abscess on the third day of hospitalization. A sample of pus sent for culture showed growth of S. intermedius sensitive to penicillin, ampicillin, ceftriaxone and vancomycin. A wound swab taken during the operation showed the growth of S. intermedius (same sensitivity) and S. aureus, sensitive to penicillin and flucloxacillin but resistant to clindamycin. The patient gradually defervesced in 3 days and was continuously afebrile until discharge. First few days, he had mild dysphagia with apparent torticollis, and his head was slightly inclined to the left. After the operation, his neck movements gradually increased, and his headache and dysphagia ceased. We started treatment with cefazoline and clindamycin for the first 2 days and then with vancomycin and meropenem for 7 days, pending microbiological results. After gaining insight into the microbiology results, we changed the therapy to penicillin G. Total intravenous therapy was 21 days. After discharge from the hospital, treatment with amoxicillin was continued for the next 3 weeks. On the 10th day of hospitalization, we performed magnetic resonance (MR) of the head and neck, which showed liquid collection (18 × 5 mm, laterolateral and anterioposterior, respectively) at the site of the retropharyngeal abscess incision downwards to C3. It also showed destruction of the clivus 11 × 8 × 10 mm (craniocaudal, anterioposterior and laterolateral, respectively), reaching the periosteum and dura mater but without forming an epidural liquid collection. The remaining MR images were unremarkable (Fig. 1A and C).FIGURE 1.: A: Sagittal short tau inversion recovery image: hyperintense signal in clivus indicates bone edema (thick arrow); hyperintense signal in epipharynx indicates edema and fluid collection (thin arrow). B: Sagittal short tau inversion recovery image: minimal residual hyperintense signal in the clivus—almost complete regression (thick arrow); normal finding in the epipharynx (thin arrow). C: Axial T2 image: hyperintense signal in the epipharynx indicates edema and fluid collection (white arrow). D: Axial T2 image: normal finding of epipharynx (white arrow).On the control visit, the patient was completely well and had free neck movement, with no fever or pain. His inflammatory markers (erythrocyte sedimentation rate and C-reactive protein) and blood count were normal. Control MR of the head and neck showed minimal residual changes (Fig. 1B and D). In conclusion, we treated a 6-year-old, previously healthy boy with a retropharyngeal abscess and clival osteomyelitis caused by S. intermedius and penicillin-sensitive S. aureus. Treatment consisted of incision and drainage of the retropharyngeal abscess and antimicrobial treatment for 6 weeks, including 3 weeks of intravenous and 3 weeks of oral therapy. The patient did well, and the treatment ended with the complete resolution of the inflammatory changes. We think that it is important to bear in mind that children with pyogenic processes of the head and neck, such as retro/parapharyngeal or peritonsillar abscess, paranasal sinusitis and otitis/mastoiditis, could also have osteomyelitis of the base of the skull because it requires prolonged antimicrobial therapy.1–4