This is drug reaction with eosinophilia and systemic symptoms (DRESS)

• maculopapular, erythematous, pruritic rash over the trunk
• marked eosinophilia
• patient taking trimethoprim-sulfamethoxazole

Notably, she has been taking the drug for a year, which is not typical for DRESS.

UTD: "The reaction typically occurs two to eight weeks after drug exposure. Medications that are taken for less than two weeks or more than three months before the onset of DRESS are unlikely to be the culprit." https://www.uptodate.com/contents/drug-reaction-with-eosinophilia-and-systemic-symptoms-dress

So yes, this is not a typical timeline. However, if you ever see rash (especially on the trunk), eosinophilia, and a high-risk drug (especially TMP-SMX) you absolutely smash the medication-rash button and move on.

No other answer choice could ever explain that huge eosinophilia.

High risk drugs: https://www.uptodate.com/contents/image?imageKey=DERM%2F129506&topicKey=DERM%2F16420&search=dress%20syndrome%20adult&rank=1~150&source=see_link

Itchy rash and eosinophilia suggests Type I hypersensitivty reaction, a side effect of sulfonamides.

• Presentation most consistent with acute interstitial nephritis, which leads to combination of rash, AKI, pyuria, hematuria, WBC casts, eosinophilia and urinary eosinophils
• Almost always caused by medication side effect, with common culprits being the 5 P’s (PPIs, Pain-free (NSAIDS), Pee (Diuretics), Penicillins and other antibiotics (especially sulfonamides such as in this patient) and rifamPin

acute interstitial nephritis from TMP-SMX causes rash, fever, and AKI with pyuria, hematuria, and eosinophilia