Lung abscess caused by Streptococcus intermedius in an immunocompetent patient

Abstract

Lung abscesses are most commonly polymicrobial, being caused by both anaerobic and aerobic bacteria, usually from the oral flora. A particular pathogen present in the oral flora, Streptococcus intermedius, has been known to cause aggressive pyogenic infections such as abscesses, most often on the soft tissues, liver and brain. Though less common, these infections can also occur in the lungs of immunocompetent individuals without preceding risk factors. In such cases, a presentation with productive cough and fever can be misdiagnosed as tracheobronchitis or pneumonia. We present the case of an immunocompetent patient without significant underlying risk factors, who was initially misdiagnosed as recurrent sinusitis, that was found to have a lung abscess due to S. intermedius infection.