RESUMEN
OBJECTIVE: To describe a case of a delayed-type hypersensitivity (DTH) reaction to piperacillin/tazobactam in which painful paresthesiae were a predominant feature. CASE SUMMARY: A 27-year-old man with a history of intravenous drug abuse was admitted for treatment of a pulmonary parenchymal abscess in the setting of lower-limb deep-venous thrombosis and methicillin-sensitive Staphylococcus aureus bacteremia. He was treated with intravenous piperacillin/tazobactam 4.5 g 3 times daily; however, after 2 weeks of therapy, he developed symptoms (eg, fever, chills) and laboratory abnormalities (eg, white blood cell count 2.1 x 10(3)/mm3, erythrocyte sedimentation rate 63 mm/h) suggestive of a DTH reaction. This was accompanied by infusion-related painful paresthesiae. The symptoms and laboratory abnormalities resolved within 48 hours of treatment being switched to flucloxacillin. DISCUSSION: Due to the close temporal association and the absence of any other obvious explanation, we believe these paresthesiae represent an additional feature of the DTH reaction to piperacillin/tazobactam in this patient. Use of the Naranjo probability scale indicated a probable relationship between the paresthesiae and administration of piperacillin/tazobactam. CONCLUSIONS: To our knowledge, as of March 24, 2006, this is the first case in which a DTH reaction to piperacillin/tazobactam manifesting as fever, neutropenia, and thrombocytopenia has been associated with paresthesiae.