About Pneumocystis pneumonia the true statement is:

Pneumocystis jirovecii is a fungus responding to Cotrimoxazole. It causes opportunistic pneumonia in patients with HIV infection.  The most common radiology finding is a normal X-ray chest.  However, the most typical X-ray is  a bat wing distribution of infiltrates with pneumocysts in peripheral fields.  Steroids are combined with Cotrimoxazole in treatment of severe Pneumocystis jirovecii pneumonia.