An analysis of clinical risk factors of deep neck infection

Objectives: To clarify the clinical risk factors that aggravate deep neck infection.

Patients and methods: Sixty-five patients with deep neck infection (abscess or cellulitis), 42 males and 23 females, who were treated at the ear, nose, and throat department in Iwaki Kyoritsu General Hospital in the past 10 years, were retrospectively reviewed. Cases of inflammation of the upper airway including the oral cavity, laryngopharynx, palate tonsil and salivary gland, and cases of lymphadenitis were investigated. These patients were divided into five localized types and one wide range type according to the abscess locations as follows: oral cavity floor type, upper deep cervical type, submandibular type, submental type, retropharyngeal type, and wide range type.

Results: Seventeen of the 65 patients had diabetes, and significantly more diabetics had the wide range type than the localized type (P<0.05, Fisher's test). Diabetes complication was more often seen in the upper deep cervical type among patients aged 61 years or older, and in the wide range type among males aged 41 years or older and elderly women aged 61 years or older. No patients with odontogenic infection or sialolithiasis had associated diabetes mellitus. Two cases developed mediastinitis, and one was caused by retrotonsillar abscess and needed thoracic drainage. More than half of the wide range type cases and more than a quarter of each of the localized type cases except the upper deep cervical type also had laryngeal edema, and eight of them needed emergency tracheotomy. Thirteen of the 40 cases had bacteria belonging to the Streptococcus milleri group (SMG), and all were detected in patients who underwent surgical drainage. Four of the 13 cases where SMG was detected showed drug resistance to some sorts of antibiotics.

Conclusion: Oral disorders can develop deep neck infection independently of the presence of diabetes mellitus, compared with other causes. The presence of diabetes mellitus is associated with deep neck infection, aggravating parotitis and wide spread of inflammation. Retrotonsillar abscess often spreads to the retropharyngeal and parapharyngeal spaces, causing mediastinitis, so caution is necessary. Infection due to SMG tends to form abscess independently of diabetes mellitus. Since more than half of the wide range type and more than a quarter of each of the localized types except the upper deep cervical type were associated with laryngeal edema, airway management should be considered.