Actinomycosis is a rare indolent infectious disease with nonspecific clinical presentations that delay diagnosis. Although actinomycosis is thought to be more prevalent in developing countries, data from developing countries are scarce. This study aimed to profile actinomycosis in developing countries and identify how it differed from profiles of developed countries.

Patients fulfilling the inclusion criteria for actinomycosis from Nanfang Hospital in southern China between January 1999 and December 2018 were retrospectively analyzed. We described clinical characteristics, diagnostic procedures, differential diagnosis, and management of actinomycosis of clinical significance.

Thirty‑one patients were included in this study. The disease was diagnosed predominately in the orocervicofacial (n = 14), cardiothoracic (n = 11), abdominopelvic (n = 5), and soft tissue (n = 1) regions. Diagnosis was obtained by either histopathology (n = 29, 94%) or microbiology (n = 2, 6%). Only one-third of patients presented with general symptoms, such as fever and weight loss. Ten were lost during follow-up, and the median duration of antibiotic use was 93.5 days (interquartile range 28–300), whereas the median follow-up time was 34 months (interquartile range 9–132). Ten patients receiving complete resection of the lesion were cured without postoperative use of antibiotics. Only one patient relapsed during the follow-up period.

Actinomycosis is a rare disease even in developing countries, and both misdiagnosis and missed diagnosis are common. Diagnosis was often delayed and was obtained postoperatively from histopathology in developing countries. Hence, clinicians should be aware of this disease in patients with high risk factors. In the future, specific molecular methods may help to improve early diagnosis and treatment.