SLR - May 2014 - Elizabeth B. Wakefield
Reference: Macy E, Contrears R. (2014). Health care use and serious infection prevalence associated with penicillin “allergy” in hospitalized patients: A cohort study. Journal of Allergy and Clinical Immunology, 15(3), 790-796.
Scientific Literature Review
Reviewed by: Elizabeth B. Wakefield, DPM
Residency Program: Grant Medical Center, Columbus, Ohio
Podiatric Relevance: Penicillin “allergy” is the most common drug-class allergy noted in medical records in the United States, and approximately 2% actually have a positive penicillin allergy test result. This “allergy” causes increased use of fluoroquinolones, clindamycin, and third-generation cephalosporins, which have been shown to have an increased prevalence of Clostridium difficile. Increased cost, length of hospital stay, and drug-resistant bacteria such as MRSA and VRE, are also a result of inaccurate penicillin “allergies”. Many hospitalized podiatric patients require antibiotics and are at a higher risk of developing C. diff, MRSA, and VRE if they report inaccurate penicillin allergy.
Methods: This was a retrospective chart review of all patients with reported penicillin allergy at time of admission over a 3 year period to multiple centers in a large geographic area. These patients were then control matched for age, gender, date of admission, and discharge billing category, to non-penicillin-allergic patients. Reports of cost and length of hospital stay, antibiotic reactions, and prevalence of C. difficile, MRSA, and VRE were recorded for both groups and statistically analyzed.
Results: Patients with reported penicillin allergy on admission, required an average 0.59 days longer admission than matched control. The cost of penicillin allergy testing was calculated and determined to be $131.37 per patient in 2012 dollars. The increased length of hospital stay compared to the cost of penicillin allergy testing is 9.5 times greater. Of the top 10 antibiotics used by both groups, significantly more ciprofloxacin, vancomycin, and clindamycin were used compared to the case control group; all of which are shown to have increased prevalence of C. difficile. Seventy-four percent of C. difficile infections, 87% of MRSA infections, and 90% of VRE infections were noted to be hospital acquired. Active penicillin “allergy” history had significantly increased rate of additional reported drug allergies at admission, as well as being twice as likely to have multiple-drug intolerance syndrome and have at least one new allergy added within the follow-up period.
Conclusions: Patients with penicillin “allergies” are more likely to contract C. difficile, MRSA, and VRE during admission, likely due to increased length of hospital stay and exposure to antibiotics that are more likely to cause C. difficile. The most common class of antibiotics used in both groups were cephalosporins, and there was no evidence of increased rate of anaphylaxis in patients with active penicillin “allergy” given cephalosporins. This is contrary to the warning label of the drug class and cross-reactivity in patients with penicillin allergy. Penicillin drug allergy is extremely easy and inexpensive to test, and it is expected that 98% of patients tested will have a negative result when coming in with a reported penicillin “allergy”. The cost savings of testing for penicillin allergies at admission is approximately 4 times the cost of treating an unconfirmed penicillin “allergy” with overall improvement of patient care and fewer serious hospital-acquired infections.