[Thoracic actinomycosis].

Actinomycosis is an infectious disease distributed all over the world. Males are affected three times more than females; the incidence of the disease is higher in adults than in children. The main causative agent is Actinomyces israelii, which can be found in the oropharynx of healthy persons. Therefore actinomycosis represents always an endogenous infection, often in connection with other bacteriae. The thoracic manifestation amounts to approximately 15 percent of all cases. The main clinical symptoms are pain, fever, cough, fatigue, and weight loss. The blood picture shows an increased number of white blood cells with a left shift in the differential white blood cell count. Furthermore, there is a strongly raised erythrocyte sedimentation rate. Radiographs demonstrate no typical patterns of pulmonary abnormalities. For the diagnosis there is a need of anaerobic cultures, in second line histological examination of tissue specimens. Differential diagnosis of actinomycosis includes chronic pneumonias caused by other rare germs and neoplasms. After early onset antibiotic long term treatment a good prognosis may be expected. Penicillin represents the antibiotic of first choice.