Donor-Derived Bactrim Allergy in a Lung Transplant Recipient

Abstract

<h3>Introduction</h3> Transplant-acquired allergies have only recently been described in the literature, most commonly as the development of <i>de novo</i> food allergies, predominantly in pediatric populations. Donor-derived antibiotic allergies, especially in the adult population, are even less commonly reported. <h3>Case Report</h3> We present the case of a donor-derived antibiotic allergy to trimethoprim-sulfamethoxazole (Bactrim) in a 73-year-old man with a history of bilateral lung transplant (11/2020) for idiopathic pulmonary fibrosis and no known drug allergies. The medical history of the lung donor included an allergy to Bactrim, with reaction described as rash and lower extremity edema. The patient's immediate postoperative course was unremarkable—he received a standard maintenance immunosuppression regimen with antiviral, antifungal, and <i>Pneumocystis jirovecii</i> prophylaxis. Given the known donor drug allergy history, Bactrim was not introduced as part of the prophylactic regimen. Instead, he received atovaquone, which was well tolerated. Follow-up clinic visits after discharge from the transplant stay showed improving pulmonary function. At this time, we estimated that the risk of anaphylaxis was low in the setting of hemodynamic stability and prednisone use, thus we introduced Bactrim at 3 months after transplant. He tolerated a small dose as we monitored for symptoms in the clinic, with instructions to return if needed. One week later, he returned to clinic with complaints of relatively diffuse urticaria in the absence of other medication or diet changes, exposures to bugs/insects, or evidence of contact dermatitis. Despite increasing prednisone dose and starting diphenhydramine, the urticaria worsened, and he developed bilateral lower extremity edema consistent with the donor's allergy history. We discontinued Bactrim at that time and resumed atovaquone. Within one week, the patient's symptoms completely resolved. <h3>Summary</h3> These observations suggest a passive transfer of sensitized passenger cells from donor to recipient. Although donor-derived antibiotic allergy is particularly rare, clinicians should remain aware of donor allergy history. Nonetheless, its clinical consequences are minimal once the medication is discontinued.