Anaplasma phagocytophilum is an emerging, Gram-negative, and obligate intracellular pathogen that is infrequently implicated as a causative agent of community-acquired pneumonia. In this paper, we report about an immunocompetent patient from the community who presented with fever, cough, and shortness of breath. Chest X-ray and CT showed bilateral lung infiltrates. Extensive workup for other common and uncommon causes of pneumonia was positive for anaplasmosis. The patient recovered completely with doxycycline therapy. In our literature review, we find that in 80% of reported cases of anaplasmosis pneumonia, empiric treatment did not contain doxycycline, which in some cases led to acute respiratory distress syndrome. Clinicians in tick-borne disease endemic regions should be aware of this unusual presentation of anaplasmosis in order to be able to select appropriate antimicrobial regimens and initiate timely management.
Keywords: Anaplasma phagocytophilum; Lyme disease; pneumonia; pneumonitis; tick-borne diseases.