Penicillin Allergy Label Increases Risk of Worse Clinical Outcomes in COVID-19

Safety of Direct Drug Provocation for the Evaluation of Penicillin Allergy in Low-Risk Adults

BACKGROUND

About 10% of patients have a penicillin allergy label, but less than 5% of them are actually allergic. Unnecessary penicillin avoidance is associated with serious medical consequences. Given the growing number of these labels, it is imperative that our diagnostic strategy for penicillin allergy be as efficient as possible. The validity of traditionally used skin tests (STs) has been questioned, whereas drug provocation testing (DPT), the criterion standard, without previous ST appears very safe in most cases.

OBJECTIVE

To evaluate the safety of direct DPT without consideration for ST results and the validity of ST in the diagnosis of penicillin allergy.

METHODS

In this prospective cohort study without a control group, we recruited patients consulting an allergist for penicillin allergy. Patients underwent ST followed by DPT regardless of ST results. Patients with anaphylaxis to penicillin within the past 5 years or a severe delayed reaction were excluded, as were those with significant cardiorespiratory comorbidity.

RESULTS

None of the 1002 recruited patients had a serious reaction to DPT. Ten (1.0%) had a mild immediate reaction, of whom only 1 (0.1%) was considered likely IgE-mediated. The positive and negative predictive values of ST for an immediate reaction were 3.6% and 99.1%, respectively.

CONCLUSIONS

In a low-risk adult population reporting penicillin allergy, ST has very poor positive predictive value. Direct DPT without ST is safe and appears to be an ideal diagnostic strategy to remove penicillin allergy labels that could be implemented in first-line practice.

Pre-Existing Allergies Patients with Higher Viral Load and Longer Recovery Days Infected by SARS-CoV-2 Omicron BA.2 in Shanghai, China, 2022

Background

It is not known whether the viral load and the number of days to negative nucleic acid increased in patients with a history of allergy during the COVID-19 pandemic.

Objective

To investigate the impact of allergy labels on SARS-CoV-2 Omicron outcomes.

Methods

This retrospective cohort study included 62,293 patients with mild Omicron infection between April 9, 2022, and May 31, 2022. Using 1:2 propensity score matching, we identified 2177 COVID-19 patients with a history of allergy and 4254 COVID-19 patients with no history of allergy. The differences in viral load, days to nucleic acid turning negative, and clinical symptoms were compared between the two groups.

Results

Compared with the group with no allergies, the number of days before negative nucleic acid conversion of COVID-19 patients with allergies was significantly higher, the viral load was significantly higher, and the cumulative negative conversion rates at 5-10 days were all lower (p < 0.01). Patients with a history of allergy to antibiotics had higher viral load and more days with negative nucleic acid levels (p < 0.001). Subgroup analysis revealed that the viral load in penicillin-allergic and cephalosporins-allergic patients was significantly compared to patients without any history of allergies (p < 0.05).

Conclusion

Patients with a history of allergy have a more significant viral load and a longer duration of nucleic acid negative conversion upon COVID-19 infection, particularly those allergic to antibiotics.

Penicillin Allergy Label Is Associated With Worse Clinical Outcomes in Bacterial Pneumonia

BACKGROUND

Penicillins (PCNs) are a first-line treatment option for bacterial pneumonia. PCN allergy label can delay antimicrobial treatment and result in the use of alternative antibiotic regimens risking an inadequate response to treatment and potentially increased adverse drug reactions.

OBJECTIVE

To investigate the impact of PCN allergy label on clinical outcomes of bacterial pneumonia.

METHODS

This retrospective cohort study used TriNetX, a web-based tool for population cohort research, to identify adult patients with and without PCN allergy label diagnosed with bacterial pneumonia. Cohorts were matched for baseline demographics and chronic medical conditions. The 30-day risks of hospitalization, acute respiratory failure, intubation, need for intensive level of care, and mortality were compared. Antibiotics used and their possible adverse reactions were explored.

RESULTS

After matching, there were 68,748 patients in each cohort. Patients with bacterial pneumonia with PCN allergy label had higher risks of hospitalization (risk ratio [RR], 1.23; 95% confidence interval [CI], 1.22-1.24), acute respiratory failure (RR, 1.14; 95% CI, 1.12-1.15), intubation (RR, 1.18; 95% CI, 1.13-1.22), intensive level of care (RR, 1.11; 95% CI, 1.08-1.14), and mortality (RR, 1.08; 95% CI, 1.04-1.13) compared with patients without PCN allergy label. Patients with PCN allergy label had decreased use of PCNs and cephalosporins and increased utilization of other antibiotic classes compared with patients without PCN allergy label. PCN allergy label was also associated with increased risk of adverse drug reactions.

CONCLUSION

PCN allergy label is associated with worse clinical outcomes in bacterial pneumonia, and risk mitigation strategies should be considered.

Differences in beta-lactam and penicillin allergy: Beyond the West and focusing on Asia-Pacific

Beta-lactam (BL) antibiotic "allergy" labels are common, but often overdiagnosed. Although much research has been focused on the BL allergy and the delabelling process in the West, studies from other parts of the world remain sparse. This review outlines the contrasting global epidemiology, shifting clinical practices and disparities of BL allergy in the Asia-Pacific region compared with the West. Innovative strategies to overcome barriers in BL allergy workup are discussed and potential directions for future research and service development are also proposed.

Negative impact of penicillin allergy labels on antibiotic use in hospitalized patients in Chinese Mainland

Background

Penicillin allergy labels have gained increasing global attention. However, to date, there are no data on the influence of penicillin allergy labels on patients in Chinese mainland.

Methods

This retrospective study reviewed the electronic health record (EHR) of hospitalized patients between June 1, 2018 and May 31, 2019. Patients with a penicillin allergy record were included in the allergy group. Every allergy patient was matched with 4 control patients by using propensity score-based matching to make sure the following were balanced: age, sex, date of admission, and the main diagnosis. We estimated the prevalence of penicillin allergy labels and compared the antibiotic prescription patterns and other clinical outcomes between the 2 groups.

Results

A total of 5691 patients and 22 585 patients were included in the allergy group and control group, respectively. The prevalence of penicillin allergy labels among the hospitalized patients in this study was 4.00%. Compared to the control group, significantly fewer patients in the allergy group were prescribed penicillins and most cephalosporins, while a larger proportion of allergy patients received clindamycin (10.02% vs 5.41%, p < 0.001) and some higher-class antibiotics, such as monobactams (1.81% vs 0.54%, p < 0.001), carbapenems (5.80% vs 4.98%, p = 0.014), macrolides (0.60% vs 0.25%, p < 0.001), and quinolones (17.62% vs 12.40%, p < 0.001). Allergy patients also had longer hospital stays and a greater need to consult infection specialists.

Conclusion

The prevalence of penicillin allergy labels was 4.00% in Chinese hospitalized patients. Penicillin allergy labels could cause irrational antibiotic prescribing, prolonged hospital stays, and greater consultation needs.