More than Valley Fever: Pulmonary Actinomycosis and Coccidioidomycosis Co-infection in a Patient.

Pulmonary coccidioidomycosis and pulmonary actinomycosis are unheard of as co-pathogens. Infection with these organisms on their own can mimic lung cancer, thus presenting a diagnostic challenge. We present the case of a 75-year-old woman presenting with haemoptysis with a chest CT chest finding of a lung mass suggestive of lung cancer. A diagnosis of concomitant infection by Coccidioides posadasii/immitis and Actinomyces odontolyticus was made based on culture and histopathology results. The patient was successfully treated with a combination of antifungal and antibacterial therapy. This is the first reported case of co-infection by these two microorganisms. LEARNING POINTS: Pulmonary coccidioidomycosis and pulmonary actinomycosis can mimic lung cancer.The diagnosis of infection by Coccidioides posadasii/immitis and Actinomyces odontolyticus is best obtained by histopathology and tissue culture.Treatment comprises a combination of oral azoles and a beta-lactam antibiotic for a total of 12 months. © EFIM 2021.