β-Lactam Allergy and Cross-Reactivity: A Clinician's Guide to Selecting an Alternative Antibiotic

Early testing and grade of the reaction are affecting factors of skin test positivity in β-Lactam allergies

Background: β-Lactams are the most widely used antibiotic family in the world. Nevertheless, they also stand out as the primary culprits for inducing drug hypersensitivity reactions (HSR). Methods: Between May 2018 and March 2023, patients with suspected HSRs to β-lactams, who underwent skin tests (ST), were retrospectively screened. The determinants of allergenic penicillin (DAP) tests, which include penicillin minor and major determinants, clavulanic acid, and amoxicillin, along with ampicillin, sulbactam, the identified culprit drugs, and alternative cephalosporins, which include cefuroxime, ceftriaxone prick and/or intradermal tests, were administered. The analysis focused on identifying positive ST results and determining the true HSRs rates in this patient cohort. Results: Of the 147 patients, 78.9% (n = 116) were women and the median (minimum-maximum) age was 41 years (18-71 years). Mild HSRs (grades 1-2) were observed in 72.78% (n = 107), whereas 24.4% (n = 36) had severe reactions (grades 3-4) and 2.7% (n = 4) had an unknown grade. Of the patients, 64% (n = 94) experienced HSRs within the first hour after the last dose of the identified culprit drug. The overall positivity rate for all STs was 26.5% (n = 39). ST positivity rates were notably higher in individuals who had experienced HSRs within the past 6 months (p = 0.02) and those with severe anaphylaxis (p < 0.001). Conclusion: β-Lactam ST positivity is higher, especially in those with grades 3-4 reactions and consulted a physician within the first 6 months after their HSRs.

Challenging dogmas: Intravenous versus oral beta-lactam antibiotic provocation tests

Background

Drug provocation tests (DPT) are considered the gold standard procedure to ascertain the diagnosis of beta-lactam (BL) allergy. Regarding route of administration, current recommendations prioritize oral challenges, considering them safer, and reserving the intravenous route for drugs for which this is the only formulation.

Objective

To compare in terms of tolerance and safety two protocols of BL DPT, using an oral protocol (OR-DPT) and an intravenous protocol (IV-DPT).

Methods

A descriptive, retrospective study was performed, including adult patients who underwent IV-DPT or OR-DPT for suspected immediate or delayed hypersensitivity to BL antibiotics, over a period of 4 years (between January 2018 and December 2021). Demographical data, index hypersensivity reactions' characteristics and tolerance to DPT were reviewed.

Results

A total of 1036 patients underwent DPT, mean age of 56.8 (standard deviation, SD, 17.8) years, 655 were women (63.2%). Immediate drug hypersensitivity reactions (DHR) had occurred in 564 of patients (54.4%). OR-DPT were performed in 439 (42.4%) and IV-DPT in 597 (57.6%). The frequency of reactions during DPT, regardless of the route used, was low (3.6%): only 16 (3.6%) in OR-DPT and 21 (3.5%) in IV-DPT. From IV-DPT, 16 out 21 DHR during DPT were immediate compared with 4 out of 16 in OR-DPT. Adjusted relative risk of developing a hypersensitivity reaction during IV-DPT versus OR-DPT was 1.13 (95% confidence interval (CI)0.57-2.22).

Conclusion

The results suggest that OR-DPT and IV-DPT are both safe procedures when adequately performed. However, IV-DPT protocols showed a higher rate of immediate DHR during DPT probably due to the selection of basal high-risk patients to undergo IV-DPT. In conclusion, IV-DPT may be considered as an option for challenges in drug-allergy studies, entailing a precise administration.

Management and Implications of Beta-Lactam Allergies

Beta-lactam antibiotics are essential components in the current antimicrobial treatment strategy, playing a crucial role in ambulatory patients and hospitalized patients. Despite their prominent therapeutic index, the use of beta-lactam can lead to adverse effects, with allergic reactions being the most concerning because of their severity. Additionally, the phenomenon of cross-reactivity may occur among various beta-lactam families, with side chains significantly contributing to immunological recognition, making these structures often responsible for the cross-allergic reactivity of beta-lactams. Tools to assess beta-lactam allergy include taking a patient's medical history, performing skin tests, and conducting provocation tests. This research aims to analyze the relevant aspects related to the safe administration of beta-lactam antibiotics in hospitalized patients as well as provide knowledge on the proper management of patients with such hypersensitivity, by doing systemic research. This research was made using Google Scholar and keywords such as "Beta-lactam allergy," "Hypersensitivity," "Cross-reactivity," "Desensitization," and "Beta-lactam allergy management." In conclusion, substituting a beta-lactam antibiotic with an alternative antibiotic may not always be the best management option for these patients, as it may lead to more adverse effects, be less effective, and prolong hospitalization time. It may also result in higher rates of antibiotic-resistant infections and increased medical costs, as these alternatives are often more expensive. However, an alternative within the beta-lactam family can be sought by conducting the appropriate analyses. Although cross-reactivity does not always occur among all beta-lactams, potential cross-reactivity should always be considered.

Sepsis Stewardship: The Puzzle of Antibiotic Therapy in the Context of Individualization of Decision Making

The main recent change observed in the field of critical patient infection has been universal awareness of the need to make better use of antimicrobials, especially for the most serious cases, beyond the application of simple and effective formulas or rigid protocols. The increase in resistant microorganisms, the quantitative increase in major surgeries and interventional procedures in the highest risk patients, and the appearance of a significant number of new antibiotics in recent years (some very specifically directed against certain mechanisms of resistance and others with a broader spectrum of applications) have led us to shift our questions from "what to deal with" to "how to treat". There has been controversy about how best to approach antibiotic treatment of complex cases of sepsis. The individualized and adjusted dosage, the moment of its administration, the objective, and the selection of the regimen are pointed out as factors of special relevance in a critically ill patient where the frequency of resistant microorganisms, especially among the Enterobacterales group, and the emergence of multiple and diverse antibiotic treatment alternatives have made the appropriate choice of antibiotic treatment more complex, requiring a constant updating of knowledge and the creation of multidisciplinary teams to confront new infections that are difficult to treat. In this article, we have reviewed the phenomenon of the emergence of resistance to antibacterials and we have tried to share some of the ideas, such as stewardship, sparing carbapenems, and organizational, microbiological, pharmacological, and knowledge tools, that we have considered most useful and effective for individualized decision making that takes into account the current context of multidrug resistance. The greatest challenge, therefore, of decision making in this context lies in determining an effective, optimal, and balanced empirical antibiotic treatment.

Risk factors for allergy documentation in electronic health record: A retrospective study in a tertiary health center in Switzerland

BACKGROUND

Most hospitals use electronic health records (EHR) to warn health care professionals of drug hypersensitivity (DH) and other allergies. Indiscriminate recording of patient self-reported allergies may bloat the alert system, leading to unjustified avoidances and increases in health costs. The aim of our study was to analyze hypersensitivities documented in EHR of patients at Lausanne University Hospital (CHUV).

METHODS

We conducted a retrospective study on patients admitted at least 24 h to CHUV between 2011 and 2021. After ethical clearance, we obtained anonymized data. Because culprit allergen could be either manually recorded or selected through a list, data was harmonized using a reference allergy database before undergoing statistical analysis.

RESULTS

Of 192,444 patients, 16% had at least one allergy referenced. DH constituted 60% of all allergy alerts, mainly beta-lactam antibiotics (BLA) (30%), NSAID (11%) and iodinated contrast media (ICM) (7%). Median age at first hospitalization and hospitalization length were higher in the allergy group. Female to male ratio was 2:1 in the allergic group. Reactions were limited to the skin in half of patients, and consistent with anaphylaxis in 6%. In those deemed allergic to BLA, culprit drug was specified in 19%, 'allergy to penicillin' otherwise. It was impossible to distinguish DH based on history alone or resulting from specialized work-up.

CONCLUSIONS

Older age, longer hospital stays, and female sex increase the odds of in-patient allergy documentation. Regarding DH, BLA were referenced in 4% of inpatient records. Specific delabeling programs should be implemented to increase data reliability and patient safety.

Polysorbate 80 as a possible allergenic component in cross-allergy to docetaxel and fosaprepitant: A literature review

OBJECTIVE

Patients had allergies to both fosaprepitant and docetaxel with similar signs and symptoms. To explore the possible causes of allergy and whether there is cross-allergy between fosaprepitant and docetaxel, we conducted a literature review according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

METHODS

A systematic search of the following databases was performed: Pubmed, Embase, Cochrane Library, CINAHL, Scopus, Web of Science and Taylor & Francis. The final search was on 12 November 2022. Two investigators independently selected eligible studies and extracted data according to inclusion and exclusion criteria and assessed the methodological quality of included studies. Any disagreement was resolved by a third researcher.

RESULTS

The main cause of fosaprepitant and docetaxel allergy is polysorbate 80. Fosaprepitant and docetaxel have similar allergic symptoms, mainly facial flushing (19.0%, 18.5%); erythema/dermatitis (17.2%, 1.9%); fluid retention (17.2%, 22.2%); and dyspnea, bronchospasm, shortness of breath and coughing (15.5%, 16.7%). Hypotension (1.7%, 7.4%) and decreased oxygen saturation (1.7%, 1.9%) are rare. The treatments for both allergies are similar: stop injection, oxygen, glucocorticoid, antihistamines and symptomatic treatments.

CONCLUSION

Polysorbate 80 is the same allergenic component of docetaxel and fosaprepitant. The symptoms and treatments caused by the two drugs are similar. Most allergic reactions are not serious. Medications containing the same allergy ingredient need to be used with caution for patients with severe allergies to polysorbate 80.

Safety Aspects and Rational Use of Single Intramuscular Dose Ceftriaxone: Clinical Insights on the Management of Uncomplicated Gonococcal Infections

Gonorrhea, a sexually transmitted infection caused by Neisseria gonorrhoeae, is a grave public health concern. Gonorrhea is the second most reported sexually transmitted infection worldwide. The treatment of uncomplicated gonococcal infections has evolved dramatically in response to the emergence of antimicrobial resistance. Multiple resistance mechanisms (for example, beta-lactamase production, antimicrobial efflux, and target site modification) exist, some of which may cause multidrug-resistance. Ceftriaxone was first recommended as an option for uncomplicated gonococcal infections in 1985, and it is now a mainstay of therapy in all clinical practice guidelines. Ceftriaxone has consistently shown high microbiologic cure rates in clinical trials, and it has demonstrated an excellent safety profile. Although its use may be limited in patients with hypersensitivity to penicillins, the risk of using ceftriaxone in such patients is overestimated. The emergence of reduced ceftriaxone susceptibility in N. gonorrhoeae, coupled with a lack of diverse treatment alternatives and the limited pipeline of new antimicrobials, is a significant threat to the treatment of gonorrhea.

Meropenem allergy testing performed at the bedside of hospitalized patients labelled with a penicillin allergy

BACKGROUND

Meropenem is a widely prescribed beta-lactam for hospitalized patients. There are few data on meropenem allergy assessments in inpatients with a reported history of penicillin allergy who require a treatment with meropenem. This can lead to the use of less effective second-line antibiotics that may increase antibiotic resistances. We aimed to evaluate the clinical outcomes of a meropenem allergy assessment in admitted patients with a reported history of penicillin allergy that required meropenem for the treatment of an acute infection.

METHODS

A retrospective analysis was performed on 182 inpatients labelled with a penicillin-allergy who received meropenem after an allergy assessment. The allergy study was performed bedside if meropenem was required urgently. The study included skin prick tests (SPTs) followed by an intradermal skin test (IDT) to meropenem, and a meropenem drug challenge test (DCT). If a non-immediate reaction to a beta-lactam was suspected, it was initiated with patch tests.

RESULTS

The median age of the patients was 59.7 years (range 28-95) and 80 (44%) were women. A total of 196 sets of diagnostic workups were performed, with 189 (96.4%) of them being tolerated. Only two patients had a positive meropenem IV DCT, both presenting a non-severe cutaneous reaction that completely resolved after treatment.

CONCLUSIONS

This study evidenced that a bedside meropenem allergy assessment of hospitalized patients labelled with a 'penicillin allergy' who require a broad-spectrum antibiotic for empiric coverage is a safe and effective procedure, avoiding the use of second-line antimicrobial agents.

Ceftazidime/avibactam-induced severe neutropenia: A case report

Ceftazidime/avibactam is an important option for the treatment of infections caused by multidrug-resistant gram-negative bacteria. Haematological abnormalities are rare adverse events. We describe a case of a 63-year-old male who developed severe neutropenia following exposure to ceftazidime/avibactam in the intensive care unit for the treatment of abdominal infections. Six days after ceftazidime/avibactam was prescribed, the patient experienced a sheer drop in absolute neutrophil count, down to a minimum of 0.13 × 109 /L. A bone marrow examination showed neutrophilic maturation arrest. After careful screening of all drugs used by the patient and other potential causes of severe neutropenia, ceftazidime/avibactam was suspected to be the most likely culprit and was therefore replaced by cefoperazone/sulbactam, while a dose of colony-stimulating factor was given. The next day, neutrophils rose to 3.64 × 109 /L. To the best of our knowledge, this is the first case report of severe neutropenia associated with ceftazidime/avibactam. When neutropenia occurs during treatment, the clinician should keep this possibility in mind. Regular monitoring of neutrophil counts for timely recognition, immediate discontinuation of the drug and substitution of antibiotics are key steps in management.

Case report: Continuous infusions of ceftazidime-avibactam and aztreonam in combination through elastomeric infusors for 12 weeks for the treatment of bone and joint infections due to metallo-β-lactamase producing Enterobacterales

Among carbapenem-resistant Enterobacterales, metallo-beta-lactamase producing strains represent a growing therapeutic challenge. While the association of aztreonam and ceftazidime-avibactam has been investigated in recent years for the treatment of infections involving these strains, little to no clinical data support the use of this association for the treatment of bone and joint infections. We report two cases of complex bone and joint infections involving metallo-beta-lactamase-producing Enterobacterales, successfully treated at our referral center with aztreonam and ceftazidime-avibactam for 12 weeks in continuous infusions through elastomeric infusors.

A large screen identifies beta-lactam antibiotics which can be repurposed to target the syphilis agent

Syphilis, caused by the spirochete Treponema pallidum subsp. pallidum (hereafter called T. pallidum), is re-emerging as a worldwide sexually transmitted infection. A single intramuscular dose of benzathine penicillin G is the preferred syphilis treatment option. Both supply shortage concerns and the potential for acquired antibiotic resistance further the need to broaden the repertoire of syphilis therapeutics. We reasoned that other β-lactams may be equally or more effective at targeting the disease-causing agent, Treponema pallidum, but have yet to be discovered due to a previous lack of a continuous in vitro culture system. Recent technical advances with respect to in vitro T. pallidum propagation allowed us to conduct a high-throughput screen of almost 100 β-lactams. Using several molecular and cellular approaches that we developed or adapted, we identified and confirmed the efficacy of several β-lactams that were similar to or outperformed the current standard, benzathine penicillin G. These options are either currently used to treat bacterial infections or are synthetic derivatives of naturally occurring compounds. Our studies not only identified additional potential therapeutics in the resolution of syphilis, but provide techniques to study the complex biology of T. pallidum-a spirochete that has plagued human health for centuries.

An overview of penicillin allergies for nurses

ABSTRACT

Antibiotics are frequently reported as allergies by patients, particularly antibiotics from the penicillin family. Most of these reported allergies are benign, and the consequences of alternative therapies can be significant. This article provides background information on penicillin allergies and serves as a guide to penicillin allergy management.Reprinted with permission from Wrynn, A.F. An overview of penicillin allergies for nurses. Nurse Pract 2022; 47(9): 30-36. Copyright Wolters Kluwer. All rights reserved.

Penicillin allergies: A guide for NPs

ABSTRACT

Antibiotics are frequently reported as allergies by patients, particularly antibiotics from the penicillin family. Most of these reported allergies are benign, and the consequences of alternative therapies can be significant. This article will deliver background information on penicillin allergies and serve as a guide to penicillin allergy management.

Amoxicillin hypersensitivity: patient outcomes in a seven-year retrospective study

BACKGROUND

The beta-lactam antibiotic amoxicillin and the beta-lactamase inhibitor clavulanic acid in combination with amoxicillin are known to both cause immediate and non-immediate type hypersensitivity.

OBJECTIVE

To characterize a large cohort of patients with a history of amoxicillin or amoxicillin-clavulanic acid hypersensitivity.

METHODS

Retrospective analysis of demographics, presentation, investigation, and management of 331 patients presenting to one allergy center with a history of hypersensitivity to amoxicillin or amoxicillin-clavulanic acid.

RESULTS

Hypersensitivity was confirmed in 37/221 (17%) patients who took amoxicillin and 47/110 (43%) patients who took amoxicillin-clavulanic acid as the index drug. In immediate hypersensitivity, skin testing confirmed the diagnosis in 66/139 (47%) patients. Penicillin cross-reactivity was observed in 16/36 (44%). 13/16 (81%) cross-reactive patients reacted to amoxicillin-clavulanic acid as the index drug. All skin test negative patients (73/139) underwent drug provocation. The negative predictive value of skin tests was 89%. In non-immediate hypersensitivity, delayed intradermal tests confirmed diagnosis in 12/170 (7%). 8/12 (67%) skin test positive patients presented with DRESS. All skin test negative patients (158/170) underwent drug provocation. The negative predictive value of skin tests was 95%. Penicillin cross-reactivity was observed in 3/12 (25%). Ten patients were diagnosed with hypersensitivity to clavulanic acid.

CONCLUSION

The negative predictive value of skin tests in both immediate and non-immediate hypersensitivity reactions is excellent and excludes severe allergy. Non-immediate hypersensitivity is rare. Confirmed hypersensitivity is more likely if amoxicillin-clavulanic acid is the index drug. Cross-reactivity was more common in patients presenting with immediate hypersensitivity, most commonly involving benzylpenicillin. A minority of patients were allergic to clavulanic acid.

CROSS-REACTIVITY TO ANTIBIOTICS: PROPOSITIONS FOR SELECTING ALTERNATIVES

OBJECTIVE

The aim: To analyze CR among antibacterials of different classes and to overcome some widespread misconceptions regarding CR between different classes of antibiotics.

PATIENTS AND METHODS

Materials and methods: The narrative review represents an assessment of the most pertinent literary sources published in English language, which dealt with the issues of cross-reactivity between individual antibiotics and different classes of these ones.

CONCLUSION

Conclusions: With a high probability of type I AR in a patient in the past, it is better to plan the treatment of patients together with an allergist / immunologist. If this probability is estimated to be low, the choice of a particular antibiotic may be based to some extent on CR data.

Risk of Multidrug Resistant Bacteria Acquisition in Patients with Declared β-Lactam Allergy during Hospitalization in Intensive Care Unit: A Retrospective Cohort Study (2007-2018)

Introduction

The risk of extended spectrum β-lactamase (ESBL) bacterial acquisition in patients with β-lactam allergy has been poorly investigated. In a previous study conducted over a 6-year long period (2007-2012), we found that patients with declared β-lactam allergy had a higher risk of ESBL bacterial carriage at admission in intensive care unit (ICU), but they had not a higher risk of ESBL bacterial acquisition. We present the final results of the study which was eventually conducted over a 12-year long period (2007-2018).

Materials and Methods

The study included all patients admitted in ICU and receiving antibiotic treatment from January 2007 to December 2018. ESBL bacterial acquisition was the main clinical outcome. Mortality in ICU, multidrug resistant bacterial carriage at admission and discharge were the secondary outcomes.

Results

Overall, 3332 patients were included, 132/3332 (3.9%) were labelled β-lactam allergic, while 3200/3332 (96.1%) did not presented β-lactam allergy. No significant difference in rates of ESBL acquisition was detected (4/132, 3% vs. 78/3200, 2.4%; p = 0.17). Patients with β-lactam allergy had higher rates of ESBL bacterial carriage at admission (19/132, 14.4% vs. 248/3200, 7.8%, p = 0.01) and at discharge (22/132, 16.7% vs. 351/3200, 11%, p = 0.04) than nonallergic patients. No differences in mortality, duration of hospitalization, and carriage of methicillin resistant Staphylococcus aureus were reported. Female gender was the only factor associated with β-lactam allergy at the multivariate analysis.

Conclusions

This study confirms that patients with declared β-lactam allergy had not a higher risk of ESBL bacterial acquisition during hospitalization in ICU. However, they had a higher ESBL bacterial carriage at admission.

Corynebacterium amycolatum infective endocarditis in a patient with severe COVID-19: a case report

Objective. To present a case of successful treatment of a secondary bacterial infection caused by nondiphtheritic corynebacterium in a patient with severe COVID-19 and known beta-lactam intolerance. Materials and Methods. A clinical case of infective endocarditis (IE) caused by Corynebacterium amycolatum in a 74-year-old patient hospitalized with severe COVID-19 is presented. Comorbidity (secondary immune deficiency due to active malignancy, chemotherapy courses; previous heart disease) and the need for immunosuppressive therapy were triggers for infection caused by a rare Gram-positive bacterium which is usually considered as clinically non-significant. The choice of empiric antimicrobial treatment was limited by the patient’s history of beta-lactam intolerance. Results. A multidisciplinary approach to medical care of the patient and alertness to secondary infections helped to diagnose IE in a timely manner and to choose effective antimicrobial therapy. Combination therapy with vancomycin and amikacin helped to make blood flow free from infection. The further switch to oral doxycycline in outpatient settings resulted in the patient recovery from the infection. Conclusions. Under conditions of limited choice of drug therapy, it is critical to have access to modern microbiological diagnostics which make it possible to diagnose rare pathogens. A dialogue between treating physician and clinical pharmacologist helps to choose an empirical and targeted antimicrobial therapy with the best efficacy-safety ratio. There is a need to be alert to secondary infections, including those of atypical locations and courses and caused by rare or opportunistic pathogens.

75% negative skin test results in patients with suspected hypersensitivity to beta-lactam antibiotics: Influencing factors and interpretation of test results

Background

The diagnostic approach for beta-lactam (BL) drug hypersensitivity reactions (DHR) is based on the history, clinical signs, skin tests (ST), in vitro tests, and drug provocation tests (DPT). The aim of this study was to assess the performance of an allergy workup with ST in a real-world use.

Methods

In this cross-sectional study the rate of positive ST in subjects with suspected DHR to penicillins and cephalosporins was investigated. Of special interest were correlations of ST positivity: 1) to the time intervals between index reaction and the allergic work-up, 2) time interval from drug exposure to the onset of signs, 3) pattern of manifestation in delayed DHR and involvement of test area in the index reaction, and 4) potential advantage of patch testing in delayed DHR.

Results

175 patients were included between January 2018 and April 2019 (63.4% female), 45 (25.7%) with immediate DHR manifestation and 130 with delayed DHR manifestation (74.3%). A total of 44 patients (25.1%) had a positive ST (immediate DHR 37.8% versus 20.0% in delayed DHR). ST positivity decreased in both groups after 3 years from 47.8% [95%CI 29.2-67] to 23.5% [95%CI 9.6-47.3] in immediate DHR and 23.0% [95%CI 15-4-32.9] to 12.9% [95%CI 5.1-28.9] in delayed DHR. The proportion of positive ST was higher in patients with more severe forms of delayed DHR, and in subjects with a shorter latency period of onset of symptoms after drug exposure: 0-3d: 29.5% [95%CI 19.6-41.9] vs. >3d: 11.6% [95%CI 6.0-21.2]). No sensitization was shown in delayed urticaria or angioedema. ST done outside the skin area involved during the index reaction were negative in all cases (0/38 vs. 26/84 in cases with involved area). The combination of patch test and intradermal test (IDT) revealed an additional positive result in 2/77 cases. Additional in vitro testing reduced the proportion of negative test results to 72%.

Conclusion

In most patients with negative test results, we could not clarify the cause of the BL-associated adverse events even with further investigations (including DPT). How to prevent new drug-induced adverse events in such patients has hardly been investigated yet. Corresponding cohort studies could improve the data situation.

Classifying cephalosporins: from generation to cross-reactivity

PURPOSE OF REVIEW

To review the most recent literature studying the classifications, immunochemistry, and crossreactivity of allergy reactions to cephalosporins.

RECENT FINDINGS

Over the last five years, research interest has focused on three areas related to cephalosporin allergy: cross-reactivity among cephalosporins and with other beta-lactams; the incidence of adverse reactions in penicillin allergy patients or in reported penicillin allergy labels; and new cephalosporins structures involved in the immunological recognition.

SUMMARY

Meta-analysis of a substantial number of studies shows that cephalosporins are safer than previously thought. Evidence supports two main conclusions in that regard. First, there is a relatively low percentage of cross-reactivity between cephalosporins and other beta-lactams with penicillins in penicillin allergy patients. Second, there is a very low incidence of allergy reactions in nonselected as well as in selected penicillin allergy patients when cephalosporins are used prior to surgical intervention.On the other hand, few structures have been discovered related to the immune mechanism of cephalosporin allergy reactions, and these are far from being ready to use in clinical practice.