Skin test concentrations for systemically administered drugs -- an ENDA/EAACI Drug Allergy Interest Group position paper

[Update on perioperative hypersensitivity reactions: joint document from the Brazilian Society of Anesthesiology (SBA) and Brazilian Association of Allergy and Immunology (ASBAI) - Part II: etiology and diagnosis]

This second joint document, written by experts from the Brazilian Association of Allergy and Immunology (ASBAI) and Brazilian Society of Anesthesiology (SBA) concerned with perioperative anaphylaxis, aims to review the pathophysiological reaction mechanisms, triggering agents (in adults and children), and the approach for diagnosis during and after an episode of anaphylaxis. As anaphylaxis assessment is extensive, the identification of medications, antiseptics and other substances used at each setting, the comprehensive data documentation, and the use of standardized nomenclature are key points for obtaining more consistent epidemiological information on perioperative anaphylaxis.

Update on perioperative hypersensitivity reactions: joint document from the Brazilian Society of Anesthesiology (SBA) and Brazilian Association of Allergy and Immunology (ASBAI) - Part II: etiology and diagnosis

This second joint document, written by experts from the Brazilian Association of Allergy and Immunology (ASBAI) and Brazilian Society of Anesthesiology (SBA) concerned with perioperative anaphylaxis, aims to review the pathophysiological reaction mechanisms, triggering agents (in adults and children), and the approach for diagnosis during and after an episode of anaphylaxis. As anaphylaxis assessment is extensive, the identification of medications, antiseptics and other substances used at each setting, the comprehensive data documentation, and the use of standardized nomenclature are key points for obtaining more consistent epidemiological information on perioperative anaphylaxis.

Diagnostic procedures & practices in drug allergy/hypersensitivity: a survey of 13 Asian countries

BACKGROUND

The issues and challenges in the diagnosis of drug allergy/hypersensitivity among children and adults in Asia are likely to be different from non-Asian countries.

OBJECTIVE

To study the diagnostic modalities used in the evaluation and management of drug allergy/drug hypersensitivity reactions (DHRs) among member societies of the Asia Pacific Association of Allergy, Asthma and Clinical Immunology (APAAACI).

METHODS

A questionnaire comprising 41 questions was circulated electronically to member societies and individual members of APAAACI between January 23, 2020 and March 6, 2020.

RESULTS

Twenty-six respondents from 15 member societies and 1 individual member responded. European DHR guidelines were most commonly used. Skin prick and intradermal testing was used by 100%, with only 60% having access to commercial penicillin skin test reagents. In vitro-specific IgE tests were used by 75%, and basophil activation test by 56.3% for immediate DHR. Patch tests were used by 75% in contrast to lymphocyte transformation tests by 25% for nonimmediate DHR. Drug provocation tests were used by 68.8%, the most common indication being to exclude hypersensitivity where history/symptoms were not suggestive of drug hypersensitivity/allergy (93.3%). Human leukocyte antigen (HLA) genotype testing was mandatory among 25% respondents before new carbamazepine prescriptions, and 8.3% for allopurinol prescriptions.

CONCLUSIONS

There was increased use of skin testing for iodinated contrast media hypersensitivity and patch testing for nonimmediate DHR. HLA genotype testing prior to new carbamazepine, allopurinol and abacavir prescriptions remain variable despite strong associations for severe cutaneous adverse reactions with Asian ethnicity. Results of this survey form a useful framework for developing educational and training needs and for improving access to drug allergy diagnostic and treatment modalities across APAAACI member societies.

Predicting Transdermal Fentanyl Delivery Using Mechanistic Simulations for Tailored Therapy

Transdermal drug delivery is a key technology for administering drugs. However, most devices are “one-size-fits-all”, even though drug diffusion through the skin varies significantly from person-to-person. For next-generation devices, personalization for optimal drug release would benefit from an augmented insight into the drug release and percutaneous uptake kinetics. Our objective was to quantify the changes in transdermal fentanyl uptake with regards to the patient’s age and the anatomical location where the patch was placed. We also explored to which extent the drug flux from the patch could be altered by miniaturizing the contact surface area of the patch reservoir with the skin. To this end, we used validated mechanistic modeling of fentanyl diffusion, storage, and partitioning in the epidermis to quantify drug release from the patch and the uptake within the skin. A superior spatiotemporal resolution compared to experimental methods enabled in-silico identification of peak concentrations and fluxes, and the amount of stored drug and bioavailability. The patients’ drug uptake showed a 36% difference between different anatomical locations after 72 h, but there was a strong interpatient variability. With aging, the drug uptake from the transdermal patch became slower and less potent. A 70-year-old patient received 26% less drug over the 72-h application period, compared to an 18-year-old patient. Additionally, a novel concept of using micron-sized drug reservoirs was explored in silico. These reservoirs induced a much higher local flux (µg cm^-2 h^-1) than conventional patches. Up to a 200-fold increase in the drug flux was obtained from these small reservoirs. This effect was mainly caused by transverse diffusion in the stratum corneum, which is not relevant for much larger conventional patches. These micron-sized drug reservoirs open new ways to individualize reservoir design and thus transdermal therapy. Such computer-aided engineering tools also have great potential for in-silico design and precise control of drug delivery systems. Here, the validated mechanistic models can serve as a key building block for developing digital twins for transdermal drug delivery systems.

Hypersensitivity Reactions to Multiple Iodinated Contrast Media

The incidence of hypersensitivity reactions (HSRs) to iodinated contrast media (ICM) has risen over last years, representing an important health problem. HSRs to ICMs are classified into immediate reactions (IRs) and non-immediate reactions (NIRs) according to if they occur within 1 h or longer after ICM administration. The diagnosis of HSRs to ICM is complex as skin test (ST) sensitivity ranges widely, and drug provocation test (DPT) protocols are heterogeneous. In this manuscript, we describe the clinical characteristics of a series of patients confirmed as HSR to ICM and the diagnosis procedure carried out, looking into those cases confirmed as HSRs to multiple ICMs. For this purpose, we prospectively evaluated patients suggestive of HSRs to ICMs and classified them as IRs or NIRs. STs were carried out using a wide panel of ICMs, and in those with a negative ST, a single-blind placebo controlled DPT was performed with the culprit. If ST or DPT were positive, then tolerance was assessed with an alternative negative ST ICM. We included 101 cases (12 IRs and 89 NIRs) confirmed as allergic. Among them, 36 (35.64%) cases were allergic to more than one ICM (8 IRs and 28 NIRs). The most common ICM involved were iomeprol and iodixanol. Although not statistically significant, the percentage of patients reporting anaphylaxis was higher in patients allergic to multiple ICMs compared with patients allergic to a single ICM (50 vs. 25%). Likewise, the percentage of positive results in STs was higher in patients allergic to multiple ICMs compared with those allergic to a single ICM (for IR 62.5 vs. 25%, p > 0.05; and for NIR, 85.71 vs. 24.59%, p < 0.000). In cases allergic to more than one ICM, DPT with negative-ST ICM was positive in more than 60% (24/36) of cases. Therefore, allergy to multiple ICMs is common, associated to severe reactions in IRs, and confirmed frequently by positive STs. The allergological work-up should include DPT not only to establish the diagnosis but also to identify safe alternative ICM, even if ICM is structurally unrelated and ST is negative. More studies are needed to clarify mechanisms underlying cross-reactivity among ICMs.

Descriptive analysis of a simplified approach to low-risk drug hypersensitivity reactions

BACKGROUND

Evaluation of drug allergy is intricate because of nonstandardized testing and challenge method variability.

OBJECTIVE

To determine the clinical and epidemiologic characteristics of a large group of patients with suspected drug allergies who underwent 1 or more provocation tests (PT), and to establish whether performing this test in fewer steps is safe and effective.

METHODS

A cross-sectional descriptive study was conducted in patients with suspected drug allergies who underwent a provocation test at the allergy service of Fundación Valle del Lili, Cali, Colombia, from January 2011 to August 2017.

RESULTS

A total of 508 patients underwent 615 PTs; the median age was 34.5 years (range, 1-87 years) and 332 were women (65.3%). The most frequently implicated drugs were nonsteroidal anti-inflammatory drugs in 362 patients (58.9%), followed by beta-lactam antibiotics in 170 (27.6%), and non-beta-lactam antibiotics in 21 (3.4%). The most typically described manifestations were cutaneous urticaria in 282 patients (45.8%) and angioedema in 220 (35.7%). Most patients underwent the PT without performing other previous tests, which were done in only 92 patients (18.3%). Skin prick tests and intradermal reaction tests were performed in 81 patients (15%); all results were negative. In 519 patients (84.3%), the PT was performed in 2 steps without a placebo. Of the PTs performed in 2 steps, 492 (94.8%) had negative results. In addition, PT was performed in 195 patients (37.6%) in whom 2 equal doses of the drug was administered; 186 patients (95.4%) had negative results.

CONCLUSION

Performing an open PT (without previous tests) in 2 steps among patients with low-risk drug reactions is safe. However, every case must be analyzed individually in terms of the risk-benefit ratio.

Adverse reaction to local anaesthetics: Is it always allergy?

OBJECTIVE

Local anaesthetics are very commonly used drugs in dentistry, and people who undergo procedures with local anaesthetics often refer adverse reactions that are not of allergic origin. Considering that in dentistry contact with allergens is very frequent, it is essential to assess the real incidence of allergy to local anaesthetics.

SUBJECTS AND METHODS

We evaluated a group of 159 patients in whom adverse reaction occurred after procedures with local anaesthetics.

RESULTS

The reactions between allergy to local anaesthetic (immediate and delayed) and certain symptoms presented by patients were investigated. Allergy to latex and chlorexidine were investigated in all patients. Only one patient, who previously presented a constant erythema at the wrist after procedure with local anaesthetics, was positive to Mepivacaine patch test. Two patients were positive to latex and one to chlorexidine.

CONCLUSIONS

The main finding of this study was that a reaction registered in the medical history and reported by a patient is rarely allergic but the use of vasoconstrictors or emotional factors may account for it. However, a complete allergological investigation is necessary for a correct diagnosis and future management.

Allergy to beta-lactam antibiotics in children: Risk factors for a positive diagnostic work-up

BACKGROUND

Allergy to beta-lactam (βL) antibiotics is highly reported in children, but rarely confirmed. Risk factors for a positive diagnostic work-up are scarce. The primary aim was to characterize the cases of children with confirmed βL allergy, investigating potential risk factors. Secondary aims were to assess the prevalence of allergy to βL in this population and to confirm the safety of less extensive diagnostic protocols for milder reactions.

METHODS

We reviewed the clinical data from all children evaluated in our Department for suspected βL allergy, over a six-year period.

RESULTS

Two hundred and twenty children (53% females) with a mean age of 6.5±4.2 years were evaluated. Cutaneous manifestations were the most frequently reported (96.9%), mainly maculopapular exanthema (MPE). The reactions were non-immediate in 59.5% of the cases. Only 23 children (10.5%) were diagnosed with allergy to βL. The likelihood of βL allergy was significantly higher in children with a family history of drug allergy (p<0.001) and in those with a smaller time period between the reaction and the study (p=0.046). The probability of not confirming βL allergy is greater in children reporting less severe reactions (p<0.001) and MPE (p<0.001). We found the less extensive diagnostic protocol in milder reactions safe, since only 4.2% of the children presented a positive provocation test (similar reaction as the index reaction).

CONCLUSION

This study highlights family history of drug allergy as a risk factor for a positive diagnostic work-up. Larger series are required, particularly genetic studies to accurately determine future risk for βL allergy in children.

S3 guidelines: Epicutaneous patch testing with contact allergens and drugs - Short version, Part 1

Epicutaneous patch testing is the diagnostic standard for the detection of allergic contact dermatitis. The present guidelines are aimed at residents and board-certified physicians in the fields of dermatology and allergology as well as other medical specialties involved in establishing the indication for patch testing and its execution in patients with contact dermatitis and other forms of delayed-type hypersensitivity. The target audience also includes other health care providers and insurance funds. Based on a systematic literature search and a formal consensus process (S3), the guidelines were developed by dermatologists in collaboration with pediatricians, occupational medicine physicians, nursing staff as well as patient representatives. The systematic methodological approach and appraisal of evidence upon which the recommendations are based are outlined in a separate method report that also contains evidence tables. The guidelines address general aspects of patch testing as well as medicolegal issues. The recommendations given relate to topics such as the indication for patch testing, informed patient consent, as well as the choice of test substances, test chambers and test site, duration of exposure, reading times and interpretation of test reactions. Furthermore, recommendations are provided with respect to endogenous and exogenous factors, specific patient groups (children, pregnant women, immunosuppressed individuals) as well as possible risks and adverse events associated with patch testing using contact allergens. Note: This publication is part 1 of the short version of the S3 guidelines for "Epicutaneous patch testing using contact allergens and drugs" (registry no. 013 - 018; date: March 20, 2019; valid until December 31, 2021). Part 2 of the short version will be published in the next issue. The long version of these guidelines can be accessed at www.awmf.org. The method report is available as online publication (https://www.awmf.org/leitlinien/detail/ll/013-018.html) and contains the evidence tables in its appendix.

Testing Strategies and Predictors for Evaluating Immediate and Delayed Reactions to Cephalosporins

BACKGROUND

Although 1% to 2% of the general population carries a cephalosporin allergy label (CAL), we lack validated testing strategies and predictors of true allergy.

OBJECTIVE

To identify cross-reactivity patterns and predictors of skin test positive (STP) in geographically disparate patients with a CAL.

METHODS

A total of 780 adult patients labeled with a CAL or penicillin allergy label (PAL) with unknown tolerance of cephalosporins identified from the Austin Hospital (Melbourne, Australia) (n = 410) and Vanderbilt University Medical Center (Nashville, TN) (n = 370) between 2014 and 2018 underwent a standardized skin testing.

RESULTS

Of 328 patients with a CAL, 29 (8.8%) tested STP to ≥1 cephalosporin(s). There were no cefazolin or ceftriaxone STP, 0 of 452 (0%), in patients with a PAL only. Of 328 patients with a CAL, 16 (4.8%) were ampicillin STP. Eleven of 16 of these patients had an initial allergy label to cephalexin. Twenty of 29 cephalosporin STP patients demonstrated tolerance to a cephalosporin with a different R1 side chain, and 8 of 14 ampicillin STP patients demonstrated tolerance to ≥1 non-amino R1 group cephalosporin. Eleven of 13 patients STP to cefazolin were skin and ingestion challenge negative to all other penicillins and cephalosporins predicted by its distinct R1/R2 groups. Seven of 15 ceftriaxone STP patients demonstrated cross-reactivity with R1-similar cephalosporins. Time since the original reaction predicted STP testing to both penicillins, adjusted odds ratio (aOR) per year 0.93 (95% confidence interval [CI]: 0.90, 0.97), and cephalosporins, aOR per year 0.71 (95% CI: 0.56, 0.90).

CONCLUSIONS

Cephalosporin cross-reactivity is based on shared R1 groupings. Increasing time since the original reaction and the presence of a PAL with unknown cephalosporin tolerance predict a lower likelihood of cephalosporin STP.

SIRM-SIAAIC consensus, an Italian document on management of patients at risk of hypersensitivity reactions to contrast media

Hypersensitivity reactions (HRs) to contrast media (CM) can be distinguished in immune-mediated (including allergic reactions) and non-immune-mediated reactions, even if clinical manifestations could be similar. Such manifestations range from mild skin eruptions to severe anaphylaxis, making it important for radiologists to know how to identify and manage them. A panel of experts from the Società Italiana di Radiologia Medica e Interventistica (SIRM) and the Società Italiana di Allergologia, Asma e Immunologia Clinica (SIAAIC) provided a consensus document on the management of patients who must undergo radiological investigations with CM. Consensus topics included: the risk stratification of patients, the identification of the culprit CM and of a safe alternative by an allergy workup, as well as the use of premedication and the correct procedure to safely perform an elective (i.e., scheduled) or urgent examination. The most important recommendations are: (1) in all patients, a thorough medical history must be taken by the prescribing physician and/or the radiologist to identify at-risk patients; (2) in patients with hypersensitivity reactions to CM, the radiologist must consider an alternative, non-contrast imaging study with a comparable diagnostic value, or prescribe a different investigation with another class of CM; (3) if such options are not feasible, the radiologist must address at-risk patients to a reference centre for an allergy evaluation; (4) if timely referral to an allergist is not viable, it is recommended to use a CM other than the responsible one, taking into account cross-reactivity patterns; in the case of patients with histories of severe reactions, the presence of an anesthesiologist is also recommended and a premedication is suggested.

Skin testing with bendamustine: what concentration should be used?

We present a case of the patient, who developed hypersensitivity reaction during the treatment of chronic lymphocytic leukemia. Bendamustine was suspected as a culprit agent. The patient as well as 3 controls underwent skin testing with the concentrations of the bendamustine described in earlier studies. We doubted the testing recommendations as all the controls developed serious local reactions. The clinical meaning of the positive skin test reaction in the patient remained unclear and questioned the safeness of recommended testing concentrations as in certain situations wrong diagnosis could be made or even harm could be done. Future investigations are needed when allergy to bendamustine is suspected.

Usefulness of an Artificial Neural Network in the Prediction of β-Lactam Allergy

BACKGROUND

An accurate diagnosis of β-lactam (BL) allergy improves the use of antibiotics, increases patients' safety, and reduces costs to health systems. Nevertheless, it requires skin and drug provocation tests, which are time-consuming and put the patient at risk. Furthermore, allergy testing is not available in circumstances such as the urgent need for antibiotic therapy.

OBJECTIVE

To evaluate the usefulness of an artificial neural network (ANN) in the prediction of hypersensitivity to BLs, and compare it with logistic regression (LR) analysis.

METHODS

In a single-center study, 656 patients evaluated for BL allergy between 1994 and 2000 were retrospectively analyzed, and the data were used to construct an ANN. The ANN predictive capabilities were compared with LR and then prospectively evaluated in 615 patients who underwent BL evaluation between 2011 and 2017.

RESULTS

A total of 1271 patients were evaluated. All patients had a definite diagnosis as allergic or nonallergic to BL. The prospective sample showed a lower percentage of patients with allergy than the retrospective sample (20.7% vs 25.8%; P = .018). In the retrospective and prospective series, the ANN reached a sensitivity of 89.5% and 81.1%, a specificity of 86.1% and 97.9%, a positive predictive value of 82.1% and 91.1%, and a negative predictive value of 92.1% and 95.2%, respectively. The ANN's performance was far superior to that of the LR, whose best performance reached a sensitivity of 31.9% and a specificity of 98.8%.

CONCLUSIONS

This ANN demonstrated a superior performance than the LR in predicting BL hypersensitivity without misdiagnosing severe allergic reactions. The ANN could be a helpful tool to classify the reaction risk, particularly in the identification of low-risk patients, in which an open challenge could be done to delabel patients.

The first case of tegoprazan-induced urticaria

WHAT IS KNOWN AND OBJECTIVE

Tegoprazan induces adverse drug reactions during clinical trials; however, tegoprazan-induced urticaria has not been reported. Here, we describe the first case of this.

CASE DESCRIPTION

A 55-year-old woman presented with acute urticaria with pruritus after taking the gastro-oesophageal reflux disease medication, tegoprazan. Urticaria disappeared after tegoprazan discontinuation. In an oral provocation test, after taking 10% of tegoprazan, she developed pruritus, and after taking 30%, she developed urticaria on her back.

WHAT IS NEW AND CONCLUSION

This is the first case of urticaria induced by tegoprazan. Physicians should understand the possibility of a tegoprazan-induced hypersensitivity reactions.

Role of in vivo and in vitro Tests in the Diagnosis of Severe Cutaneous Adverse Reactions (SCAR) to Drug

Severe cutaneous adverse reactions (SCAR) are life-threatening conditions including acute generalized exanthematous pustulosis (AGEP), Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN) and drug reaction with eosinophilia and systemic symptoms (DRESS). Diagnosis of causative underlying drug hypersensitivity (DH) is mandatory due to the high morbidity and mortality upon re-exposure with the incriminated drug. If an underlying DH is suspected, in vivo test, including patch tests (PTs), delayed-reading intradermal tests (IDTs) and in vitro tests can be performed in selected patients for which the suspected culprit drug is mandatory, or in order to find a safe alternative treatment. Positivity of in vivo and in vitro tests in SCAR to drug varies depending on the type of reaction and the incriminated drugs. Due to the severe nature of these reactions, drug provocation test (DPT) is highly contraindicated in patients who experienced SCAR. Thus, sensitivity is based on positive test results in patients with a suggestive clinical history. Patch tests still remain the first-line diagnostic tests in the majority of patients with SCAR, followed, in case of negative results, by delayed-reading IDTs, with the exception of patients with bullous diseases where IDTs are still contra-indicated. In vitro tests have shown promising results in the diagnosis of SCAR to drug. Positivity is particularly high when the lymphocyte transformation test (LTT) is combined with cytokines and cytotoxic markers measurement (cyto-LTT), but this still has to be confirmed with larger studies. Due to the rarity of SCAR, large multi-center collaborative studies are needed to better study the sensitivity and specificity of in vivo and in vitro tests.

Drug Allergy in Children: What Should We Know?

The drug allergy "label" may have a lifetime of consequences for a child. Many children with alleged drug allergies are proven to be tolerant to the culprit medication when challenged. The field of drug hypersensitivity is a recently evolving field of research, but studies on its epidemiology and diagnostic tools are lacking in children. Clinical history is significant in the diagnosis and classification of drug hypersensitivity in children. Diagnostic tools have been evaluated in a limited number of children; therefore, the guidelines are mainly in line with those for adults. Here, we review the clinical characteristics, main drugs, risk factors, and diagnosis of drug hypersensitivity to aid in its accurate diagnosis in children.

Towards a more precise diagnosis of hypersensitivity to beta-lactams - an EAACI position paper

A recent survey of the European Academy of Allergy and Clinical Immunology (EAACI) Drug Allergy Interest Group (DAIG) on how European allergy specialists deal with beta-lactam (BL) hypersensitivity demonstrated a significant heterogeneity in current practice, suggesting the need to review and update existing EAACI guidelines in order to make the diagnostic procedures as safe and accurate, but also as cost-effective, as possible. For this purpose, a bibliographic search on large studies regarding BL hypersensitivity diagnosis was performed by an EAACI task force, which reviewed and evaluated the literature data using the GRADE system for quality of evidence and strength of recommendation. The updated guidelines provide a risk stratification in BL hypersensitivity according to index reaction(s), as well as an algorithmic approach, based on cross-reactivity studies, in patients with a suspicion of BL hypersensitivity and an immediate need for antibiotic therapy, when referral to an allergist is not feasible. Furthermore, the update addresses availability and concentrations of skin test (ST) reagents, ST and drug provocation test (DPT) protocols, and diagnostic algorithms and administration of alternative BL in allergic subjects. Specifically, distinct diagnostic algorithms are suggested depending on risk stratification of the patient into high and low risk based on the morphology and chronology of the reaction, immediate (ie, occurring within 1-6 hours after the last administered dose) or nonimmediate (ie, occurring more than 1 hour after the initial drug administration), and the reaction severity. Regarding the allergy workup, the main novelty of this document is the fact that in some low-risk nonimmediate reactions ST are not mandatory, especially in children. For DPT, further studies are necessary to provide data supporting the standardization of protocols, especially of those regarding nonimmediate reactions, for which there is currently no consensus.

Intradermal Tests With Drugs: An Approach to Standardization

Background: Intradermal tests (IDTs) are performed and interpreted differently in drug allergy centers making valid comparison of results difficult.

Objective: To reduce method-related and intercenter variability of IDTs by the introduction of a standardized method.

Materials and methods: In 11 centers of the European Network for Drug Allergy, IDTs were prospectively performed with saline and with amoxicillin (20 mg/ml) using (1) the local method and (2) the standardized European Network in Drug Allergy (ENDA) method (0.02 ml). The diameters of the initial injection wheal (Wi) for the different volumes and sites injected obtained from each center were analyzed.

Results: The most reproducible method was to fill a syringe with test solution, then expel the excess fluid to obtain exactly 0.02 ml. The median Wi diameter with 0.02 ml injection using the standardized method was 5 mm [range 2–10 mm; interquartile range (IQR) 5–5 mm; n = 1,096] for saline and 5 mm (range 2–9 mm; IQR = 4.5–5 mm; n = 240) for amoxicillin. IDT injection sites did not affect the Wi diameter. Training improved precision and reduced the variability of Wi diameters.

Conclusion: Using the standardized IDT method described in this multicenter study helped to reduce variability, enabling more reliable comparison of results between individuals and centers.

Clinical Characterization and Diagnostic Approaches for Patients Reporting Hypersensitivity Reactions to Quinolones

BACKGROUND

Quinolones are the second most frequent cause of hypersensitivity reactions (HSRs) to antibiotics. A marked increase in the number of patients with HSRs to quinolones has been detected.

OBJECTIVE

To describe the clinical characteristics of patients with HSRs to quinolones and present methods for their diagnosis.

METHODS

Patients attending the allergy unit due to reactions suggestive of HSRs to quinolones were prospectively evaluated between 2005 and 2018. Diagnosis was achieved using clinical history, skin tests (STs), basophil activation tests (BATs), and drug provocation tests (DPTs) if ST and BAT results were negative.

RESULTS

We included 128 subjects confirmed as having HSRs to quinolones and 42 found to be tolerant. Anaphylaxis was the most frequent entity in immediate HSRs and was most commonly induced by moxifloxacin. Patients were evaluated a median of 150 days (interquartile range, 60-365 days) after the reaction. Of patients who underwent ST and BAT, 40.7% and 70%, respectively, were positive. DPT with a quinolone was performed in 48 cases, giving results depending on the culprit drug: when moxifloxacin was involved, 62.5% of patients gave a positive DPT result to ciprofloxacin, whereas none reacted to levofloxacin. The risk of HSR was 96 times higher in subjects who reported moxifloxacin-induced anaphylaxis and 18 times higher in those reporting immediate reactions compared with clinical entities induced by quinolones other than moxifloxacin and nonimmediate reactions.

CONCLUSIONS

The diagnosis of HSR to quinolones is complex. The use of clinical history is essential as a first step. BAT shows higher sensitivity than STs. DPTs can be useful for finding safe alternative quinolones.

The role of drug, dose, and the tolerance/intolerance of new drugs in multiple drug hypersensitivity syndrome

BACKGROUND

Multiple drug hypersensitivity syndrome (MDH) is used to describe persons with a drug hypersensitivity reaction (DHR) to at least two chemically unrelated drugs, confirmed by skin test or in vitro assay.

METHODS

Medical records of 25 patients with MDH, tested and confirmed at our allergy division, were retrospectively evaluated in terms of clinical course, involved drugs, daily drug dose, latency periods, test results of skin test and cellular assays, and tolerated drugs in subsequent pharmacological treatments.

RESULTS

Multiple drug hypersensitivity syndrome almost exclusively appeared as a delayed, often severe DHR and started in 14/25 with a drug reaction with eosinophilia and systemic symptoms (DRESS). Penicillins (13/25, 52.0%) and cephalosporins (6/25, 24.0%), typical high-dose drugs, were most often identified as elicitors of MDH, especially at the first DHR, followed by aromatic antiepileptics (7/25, 28.0%), vancomycin (4/25, 16.0%), and antibiotic sulfonamides (4/25, 16.0%). Cephalosporins, clindamycin, and radio contrast media (RCM) were mainly involved in subsequent DHR. The median daily drug dose of all drug trigger was 1875.0 mg (662.5; 2100.0) at the first DHR and 600.0 mg (300.0; 1300.0) at subsequent DHR, P = .0420.

CONCLUSION

High-dose drugs, especially beta-lactam antibiotics, RCM and clindamycin, are common elicitors of subsequent DHR in patients with MDH. Macrolides, quinolones, doxycycline, nonaromatic antiepileptics, and paracetamol were often tolerated. As the same drugs elicited both flare-up reactions and real DHR, drug-induced flare-up reactions may be precursors of a possible second DHR and MDH. The administration of highly dosed drugs should be avoided in patients at risk for MDH.

Galactose-α-1,3-galactose (alpha-gal) allergy: first pediatric case in a series of patients in Spain

INTRODUCTION AND OBJECTIVES

Allergy to galactose-α-1,3-galactose (alpha-gal) is a peculiar form of food allergy generally manifesting as an anaphylactic reaction hours after mammalian meat consumption, due to the presence of specific IgE against this oligosaccharide. In addition, immediate anaphylaxis may develop after exposure to other sources of alpha-gal, such as monoclonal antibody cetuximab, vaccines, plasma expanders or anti-snake venoms. Sensitization to alpha-gal has also been implicated in the rapid degeneration of biological valve implants, and recognized as a cause of occupational disease in cattle raisers. The implication of tick bites in this type of sensitization has been accepted by all the research groups dedicated to this disease.

PATIENTS AND METHOD

The present study describes the clinical and sensitization characteristics of 39 patients diagnosed with alpha-gal allergy in the hospitals of our province (Lugo, Monforte de Lemos and Burela, Spain).

RESULTS

Most patients were middle-age males. Of note, is the fact that the series includes the first pediatric patient reported in Spain to date. The predominant clinical manifestations were urticaria or delayed anaphylaxis after consumption of mammalian meat. Seventy-four percent of the patients reported having suffered a previous tick bite, and the clinical presentation of anaphylaxis was significantly more prevalent in those with a persistent local reaction following the bite than in those with no such reaction (p = 0.032).

CONCLUSIONS

A review is also made of the disorder which, due to its variable clinical expression, is referred to as alpha-gal syndrome. The study concludes that a diagnosis of alpha-gal allergy should be considered in patients with urticaria-anaphylaxis of uncertain origin or manifesting after the administration of vaccines or products of bovine/porcine origin.

The diagnosis of hypersensitivity to antibiotics is rarely confirmed by allergy work-up in cystic fibrosis patients

Cystic fibrosis (CF) patients receive many antibiotic treatments for recurrent respiratory infections and frequently report antibiotic hypersensitivity reactions (HSRs). In this retrospective study, medical records of CF patients were reviewed to clarify the clinical features, the culprit antibiotics, and the prevalence of antibiotic HSRs in the CF population. From 601 CF patients, 95 suspected antibiotic HSRs occurred in 60 patients (prevalence of 10.0%). β-Lactams were the most common inducers, but cotrimoxazole was also frequently involved. Seventy-six of 95 suspected HSRs were assessed by allergy workup including skin tests (43/76 reactions) and/or drug reintroduction as a full course of the culprit antibiotic (73 of 76 reactions). From the 43 suspected HSRs that were skin-tested, only three had positive skin tests and were not subjected to drug readministration. All the other 73 suspected HSRs received a full course of the culprit antibiotic: HSR symptoms recurred in 10 of 73 cases and therefore were considered as confirmed antibiotic HSRs; for the remaining 63 suspected HSRs that did not relapse after drug readministration, the diagnosis of antibiotic HSRs was excluded. In summary, 13 of 76 suspected HSRs were confirmed as antibiotic HSRs. The prevalence of suspected and confirmed antibiotic HSRs in CF patients appears similar to that reported in the general population. Of note, most of the antibiotic suspected HSRs are not confirmed after allergology workup. A complete allergy workup appears therefore crucial to make a correct diagnosis and to avoid unnecessary contraindication of major antibiotics.

Drug hypersensitivity in the fast lane: What clinicians should know about phenotypes, endotypes, and biomarkers

OBJECTIVE

To review novel concepts in drug hypersensitivity and the management of immediate hypersensitivity reactions.

DATA SOURCES

English language literature on MEDLINE and Embase surrounding drug hypersensitivity and desensitization.

STUDY SELECTIONS

References were selected based on relevance, date of publication, and originality.

RESULTS

There are numerous citations looking at categorizing drug reactions, pathogenesis, biomarkers, and desensitization. Current understanding supports the use of a phenotype-endotype-biomarker model for categorizing immediate hypersensitivity reactions. Drug desensitization is a powerful therapeutic strategy that enables temporary induction of tolerance to medications that triggered immediate reactions.

CONCLUSION

Immediate hypersensitivity reactions are diverse in presentation and pathogenesis. Drug desensitization is an effective intervention with sufficient evidence to support its more widespread availability.

Anaphylaxis caused by butylscopolamine bromide: a case report

Background

There have been only few reports on butylscopolamine-induced anaphylaxis despite its global usage as an anticholinergic agent for approximately 70 years. We present a case of anaphylaxis caused by butylscopolamine.

Case presentation

A 63-year-old woman underwent gastrointestinal endoscopic examination. She developed facial cyanosis and hypoxia after intravenous administration of butylscopolamine 10 mg, and her blood pressure was unmeasurable. Her hemodynamic condition recovered after a total of 0.6 mg adrenaline and bolus administration of 100 mg hydrocortisone. One hour after the onset of hypotension, both plasma histamine and serum tryptase were remarkably elevated to 271.7 nmol/L and 174 μg/L, respectively. Skin tests performed 47 days after anaphylaxis showed a positive result only for butylscopolamine among the exposed agents, which was confirmed by basophil activation tests using CD203c and CD63 as markers.

Conclusion

Butylscopolamine has the potential to cause severe anaphylaxis; hence, identification of the causative agent is important to prevent recurrence of anaphylaxis.

Perioperative approach of allergic patients

Perioperative allergic reactions are rare, yet important complications of anesthesia. Severe, generalized allergic reactions called anaphylaxis are estimated to have a mortality of 3.5-4.8%. Adequate recognition and handling of a severe perioperative anaphylactic reaction result in better outcomes, including less hypoxic-ischemic encephalopathy and death. The diagnosis of a perioperative allergic reaction can be difficult as the list of possible culprits of a perioperative allergic reaction is extensive. Making an informed guess on the causative agent and avoiding this agent in future anesthesia procedures is undesirable and unsafe. Therefore, to ensure future patient safety, a thorough investigation following a perioperative allergic reaction is mandatory. A collaborate approach by allergists and anesthesiologists is advised. In this article, we discuss the basic approach of the allergic patient and of patients with a suspected allergy to perioperatively administered medication.

Chlorhexidine Allergy: Current Challenges and Future Prospects

Chlorhexidine is a synthetic bisbiguanide antiseptic and was introduced in healthcare use in 1954. Allergy to chlorhexidine has been increasingly reported particularly in the perioperative and medical procedural settings. The hypersensitivity reactions range from mild cutaneous reactions to anaphylaxis or death. There are many products and medical devices containing chlorhexidine that sometimes lack standardized labeling. With the various routes of chlorhexidine exposure, accidental or recurrent reactions in chlorhexidine-allergic patients have been reported. Therefore, we aim to review the most recent evidence in clinical manifestations, diagnostic methods, management, and preventive measures with a focus on the unique features of chlorhexidine allergy.

Progress in understanding hypersensitivity reactions to nonsteroidal anti-inflammatory drugs

Nonsteroidal anti-inflammatory drugs (NSAIDs), the medications most commonly used for treating pain and inflammation, are the main triggers of drug hypersensitivity reactions. The latest classification of NSAIDs hypersensitivity by the European Academy of Allergy and Clinical Immunology (EAACI) differentiates between cross-hypersensitivity reactions (CRs), associated with COX-1 inhibition, and selective reactions, associated with immunological mechanisms. Three phenotypes fill into the first group: NSAIDs-exacerbated respiratory disease, NSAIDs-exacerbated cutaneous disease and NSAIDs-induced urticaria/angioedema. Two phenotypes fill into the second one: single-NSAID-induced urticaria/angioedema/anaphylaxis and single-NSAID-induced delayed reactions. Diagnosis of NSAIDs hypersensitivity is hampered by different factors, including the lack of validated in vitro biomarkers and the uselessness of skin tests. The advances achieved over recent years recommend a re-evaluation of the EAACI classification, as it does not consider other phenotypes such as blended reactions (coexistence of cutaneous and respiratory symptoms) or food-dependent NSAID-induced anaphylaxis. In addition, it does not regard the natural evolution of phenotypes and their potential interconversion, the development of tolerance over time or the role of atopy. Here, we address these topics. A state of the art on the underlying mechanisms and on the approaches for biomarkers discovery is also provided, including genetic studies and available information on transcriptomics and metabolomics.

IgE allergy diagnostics and other relevant tests in allergy, a World Allergy Organization position paper

Currently, testing for immunoglobulin E (IgE) sensitization is the cornerstone of diagnostic evaluation in suspected allergic conditions. This review provides a thorough and updated critical appraisal of the most frequently used diagnostic tests, both in vivo and in vitro. It discusses skin tests, challenges, and serological and cellular in vitro tests, and provides an overview of indications, advantages and disadvantages of each in conditions such as respiratory, food, venom, drug, and occupational allergy. Skin prick testing remains the first line approach in most instances; the added value of serum specific IgE to whole allergen extracts or components, as well as the role of basophil activation tests, is evaluated. Unproven, non-validated, diagnostic tests are also discussed. Throughout the review, the reader must bear in mind the relevance of differentiating between sensitization and allergy; the latter entails not only allergic sensitization, but also clinically relevant symptoms triggered by the culprit allergen.

Hypersensitivity Reactions to Biologicals: from Bench to Bedside

Purpose of Review

Biologic agents are new treatment options for chronic inflammatory diseases and cancers. As a result of their unique mechanism of action, they are more effective and less toxic treatment option and their clinical usage is increasing. While they are more commonly used, various adverse effects have been observed including life-threatening ones, including anaphylaxis. The aim of this review is to distinguish the anaphylaxis from other hypersensitivity reactions (HSR) and provide a management algorithm for the anaphylactic reactions induced by biological agents.

Recent Findings

Many case reports and series have been published regarding anaphylaxis and other hypersensitivity reactions (concerning cytokine release syndrome, acute infusion–related reactions) due to biologic agents. Although acute treatment of HSR varies according to the clinical presentation, desensitization with the drug is the major management option for subsequent administrations in the case of anaphylactic reactions.

Summary

Anaphylaxis and other immediate onset hypersensitivity reactions are occasionally difficult to differentiate from each other, and mixed-type reactions may be observed. Immediate management of anaphylaxis includes discontinuation of infusion, immediate administration of adrenaline, antihistamines, corticosteroids, and other treatment options depending on the symptoms. After 30–120 min of the reaction, a blood sample for serum tryptase levels should be obtained and after 4–6 weeks skin testing with the culprit drug should be performed for decision of long-term management via either graded challenge or desensitization.