Odontogenic deep neck infection progressing to descending necrotizing mediastinitis and sepsis: A case report

Descending necrotizing mediastinitis (DNM) is a rare but potentially fatal complication of odontogenic infection. A 62-year-old woman with diabetes mellitus presented with left facial swelling and sepsis manifested by severe hypotension and hypoxemia; the source was a periapical abscess of the left mandibular second premolar. Contrast-enhanced CT showed a deep neck abscess with gas-containing collections extending along the left carotid space into the mediastinum, accompanied by marked airway narrowing. Emergency cervical incision and drainage confirmed necrotizing fasciitis. On post-admission day 8, follow-up CT demonstrated progression of the mediastinal gas locules to a frank abscess requiring thoracic surgical drainage. This case illustrates how a localized odontogenic infection can progress to DNM and highlights serial contrast-enhanced CT as an adjunct for assessing disease progression and the need for additional surgical source control. Successful management requires airway control, broad-spectrum antimicrobial therapy, adequate cervical and mediastinal drainage, intensive sepsis care, and multidisciplinary collaboration.