The patient has Pneumocystis jirovecii pneumonia which usually only occurs in the immunocompromised. It is treated with trimethoprim/sulfamethoxazole (TMP/SMX), so it must be determined if the patient has a sulfa allergy. Although it is important to ask if the patient has been appropriately vaccinated, this does not specifically relate to the treatment plan. It is unimportant if the patient has recently been treated with penicillins. Asking if side effects are the reason for the patient’s noncompliance is not particularly conducive to open, therapeutic communication and does not address the patient’s need for TMP/SMX.