2. Department of Clinical Pharmacy and Outcomes Sciences, South Carolina College of Pharmacy-USC Campus, 715 Sumter Street Columbia, SC 29208, USA.
3. Clinical Pharmacist, Critical Care Vidant Medical Center PO Box 6028 Greenville, NC 27835, USA.
Purpose: The purpose of this case report is to describe the successful application of a cefazolin desensitization protocol in a penicillin allergic patient and to discuss the potential advantages for the use of desensitization protocols in commonly encountered Staphylococcal infections.
Summary: A 64 year old Caucasian man presented to the hospital with lower extremity pain and petechiae. Allergies documented in the medical chart at admission include amoxicillin and cefotetan. The patient was started on vancomycin 1 gram every 12 hours (14 mg/kg) empirically which was continued for 14 days. Two out of 2 blood cultures revealed MSSA. The patient's signs and symptoms improved and he was discharged on hospital day 16 after completing 14 days of vancomycin therapy for his MSSA bacteremia. Less than 72 hours after discharge, the patient presented again to the hospital with increasing lower extremity edema and fever. Infectious diseases consult on day 2 of hospitalization recommended continuing vancomycin due to abscess the documented reaction of severe itching with penicillin. On day 5, surgical debridement of the lower extremity abscesses was performed and the infectious diseases team recommended cefazolin desensitization followed by a 2-week course of cefazolin. The patient tolerated the desensitization protocol and was continued on cefazolin 1 gram every 8 hours for 14 days. The patient improved significantly and repeat blood cultures on day 18 of hospitalization were negative.
Conclusion: For patients that have a true allergy to penicillin, desensitization should be a consideration to facilitate beta-lactam therapy in the management of patients with invasive MSSA infections. When performed appropriately, desensitization can be a safe alternative with minimal risk for serious adverse reactions.
Keywords: Desensitization, beta-lactam, cefazolin, MSSA