[Tonsillar actinomycosis as a rare cause of oral malodor. Diagnosis beyond a gastroenterologist's nose].

Background: Up to 30% of patients seen by dentists suffer from oral malodor. Part of them report serious distress and a sometimes paradoxical discrepancy in subjective and objective perception of symptoms. Less often, patients with oral malodor are primarily seen by general practitioners and specialists like gastroenterologists or ear, nose and throat (ENT) doctors. Correct characterization of the underlying disease and an adequate diagnosis are made most successfully through interdisciplinary cooperation.

Case Report: The case of a 43-year-old female patient is reported who presented with persistent oral malodor for > 1 year in the authors' outpatient department. Extensive diagnostic tests performed by various doctors in the past had not led to an adequate diagnosis and treatment. Clinical and laboratory examination in the authors' hospital showed normal findings apart from suspicion of chronic tonsillitis, confirmed by an ENT specialist. Therefore, tonsillectomy was performed. Histopathology revealed chronic tonsillitis with tonsillar actinomycosis but no other disease. 6 months after tonsillectomy the patient presented asymptomatic and comfortable. Oral malodor was no longer detectable.

Conclusion: Oral malodor has a broad differential diagnosis including chronic tonsillitis caused by Actinomyces species and concomitant anaerobic bacteria able to produce volatile sulphur compounds and other putrefactive molecules. Therapeutic gold standard in symptomatic disease is tonsillectomy, lacking comparative studies on the success rates of conservative antibiotic therapy, e.g., with aminopenicillins plus beta-lactamase inhibitor for several weeks or months. This case presentation illustrates that anticipated internal disease with an agonizing and prolonged cause of disease could be solved by tonsillectomy.