Clinical manifestations of actinomycosis in Southern Taiwan

Actinomycosis is an uncommon and frequently misdiagnosed infection that may present as an acute or indolent process. Even when clinical suspicion is high, the disease is commonly confused with other chronic inflammatory diseases and malignancy. An early diagnosis helps the clinician in deciding treatment and can avoid physical morbidity such as unwarranted surgery.

We retrospectively evaluated the histopathology and selected clinical information on all cases of actinomycosis that occurred at Kaohsiung Veterans General Hospital in Taiwan from 1993 to 2005. Data on the demographic characteristics, predisposing conditions, clinical presentations, diagnosis and treatment were analyzed.

A total 36 cases of actinomycosis were identified and evaluated. The mean age of patients was 52.14 +/- 13.28 years, and the male-to-female ratio was 1:1.1. Only three types of actinomycosis were found in this study: cervicofacial, at an incidence of 31%; thoracic (33%); and pelvic (36%). The clinical manifestations depended upon the region of infection; the most frequent presentations of cervicofacial, thoracic and pelvic actinomycosis were cutaneous soft tissue swelling with drainage sinus formation (55%), hemotypsis (75%) and abnormal vaginal spotting (54%), respectively. The most common initial laboratory abnormalities were normochromic anemia (69%) and leukocytosis (25%). While most patients had no history of a foreign body, all pelvic actinomycotic patients had a history of intrauterine device use. Nineteen patients (53%) had no comorbid conditions and 11 patients (31%) had malignancy. Most patients were initially diagnosed as malignancy (56%). All patients with actinomycosis were diagnosed by histopathologic findings. Twenty two patients (61%) were treated by surgery combined with antibiotics, 11 patients (31%) by surgery only and 3 patients (8%) by antibiotics only. No recurrence or mortality occurred.

Actinomycosis should be included in the differential diagnosis when patients present with chronic drainage sinus, chronic hemoptysis and abnormal vaginal spotting with use of intrauterine devices.