S2549 Sulfasalazine-Induced DRESS Syndrome Precipitated by Recent Amoxicillin Use

INTRODUCTION: Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) Syndrome is a drug induced type IVb hypersensitivity syndrome that presents with skin eruptions, fever, lymphadenopathy, hepatitis, eosinophilia, and atypical lymphocytes. Prompt diagnosis is important as it has a mortality rate of 10%. Symptoms of this syndrome are noticed 2-8 weeks after initiation of the offending agent. We present a case of Sulfasalazine (SSZ) induced DRESS syndrome likely precipitated by recent Amoxicillin use. CASE DESCRIPTION/METHODS: 27-year-old female with history of ulcerative colitis (UC) presented with congestion, cough, and fever for 1 week and diarrhea, dark stool, and rash for 2 days. She started amoxicillin for strep throat 1 week before which was switched to azithromycin after she developed rash. RSV, influenza, and COVID were negative. She also started SSZ 3 weeks before for UC. In ED, she was tachycardic, tachypneic and febrile with a diffuse rash (Figure 1). Labs showed high LFTs and INR (Figure 2). CT chest showed axillary lymphadenopathy with findings concerning for pneumonia (Figure 3a). Azithromycin and ceftriaxone were started. Drug-induced pathology was suspected due to high eosinophil count and rash therefore SSZ was stopped. Work up was negative for ANA, AMA, ASMA, HAV, HBV, HCV, EBV IgM and C. diff toxin but positive for EBV IgG and FOBT, hence UC flareup was suspected. Therefore, budesonide and pantoprazole were started. Hospital course was complicated by acalculous cholecystitis with subsequent laparoscopic cholecystectomy. Follow up CT scan showed moderate ascites. Due to worsening LFTs, she was transferred to a transplant center. Further workup included ceruloplasmin, iron panel, CMV, HHV-6, HSV 1/2, VZV and liver/kidney microsomal antibodies which were negative. TFTs showed low TSH 0.09 and T3 62 but high FT4 1.75. Rash punch biopsy showed findings consistent with drug eruption (Figure 3b). She was started on Methylprednisolone 1 g IV daily for 3 days. LFTs trended down with marked improvement in symptoms. She was discharged on steroid taper. DISCUSSION: Early detection and withdrawal of the causal agent are key to prevent mortality and morbidity. Steroids are the gold standard of treatment with rapid resolution of symptoms, as was noticed in our patient. There have been previous reports of SSZ induced DRESS syndrome elicited by recent Amoxicillin use. Physicians should practice caution when starting Amoxicillin in patients already on SSZ to avoid this life-threatening condition.Figure 1.: Demonstrating a confluent macular rash and edema of the left upper extremity. Rash was generalized with involvement of trunk and all extremities.Figure 2.: Demonstrating lab trend of our patient over the course of her hospital stay.Figure 3.: Figure 3a demonstrating CT scan finding of mild bilateral axillary lymphadenopathy. Figure 3b shows the hematoxylin and eosin staining microscope slide of the left lower extremity punch biopsy specimen with superficial perivascular lymphocytic infiltrate signifying dermatitis (blue arrows) and numerous eosinophils (black arrows) which are findings consistent with DRESS syndrome.