Pneumocystosis

This code represents an infection caused by the fungus Pneumocystis jirovecii (formerly Pneumocystis carinii), primarily affecting the lungs and causing a severe form of pneumonia. It is an opportunistic infection, most commonly seen in immunocompromised individuals.

Assign this code when documentation confirms a diagnosis of pneumocystosis, typically Pneumocystis pneumonia (PCP). This diagnosis is often supported by microscopic identification of the organism in respiratory specimens (e.g., bronchoalveolar lavage) or a strong clinical suspicion in an immunocompromised patient with characteristic symptoms and imaging findings.

• Always query for definitive organism identification if only "PCP" is documented without specifying Pneumocystis jirovecii.
• Code any underlying immunocompromising condition (e.g., HIV, malignancy, organ transplant) as a primary or secondary diagnosis, as appropriate.
• Distinguish from other forms of pneumonia; this code is specific to Pneumocystis infection.