EAACI/ENDA position paper on drug provocation testing.

In drug hypersensitivity, drug provocation testing (DPT), also called drug challenge, is the gold standard for investigation. In recent years, risk stratification has become an important tool for adjusting the diagnostic strategy to the perceived risk, whilst still maintaining a high level of safety for the patient. Skin tests are recommended before DPT but may be omitted in low-risk patients. The task force suggests a strict definition of such low-risk patients in children and adults. Based on experience and evidence from studies of allergy to beta-lactam antibiotics, an algorithm on how to adjust DPT to the risk, and when to omit skin tests before DPT, is presented. For other antibiotics, non-steroidal anti-inflammatory drugs and other drugs, skin tests are poorly validated and DPT is frequently necessary. We recommend performing DPT with chemotherapeutics and biologicals to avoid unnecessary desensitization procedures and DPT with skin tests negative contrast media. We suggest DPT with anesthetics only in highly specialized centers. Specifics of DPT to proton pump inhibitors, anticonvulsants and corticosteroids are discussed. This position paper provides general recommendations and guidance on optimizing use of DPT, whilst balancing benefits with patient safety and optimizing the use of the limited available resources.

Desensitization in children allergic to drugs: Indications, protocols, and limits.

Any drug can potentially induce a hypersensitivity reaction. If after the allergological work-up the drug hypersensitivity reaction is confirmed, in most cases, the simple avoidance of the culprit drug and a suggestion of an unrelated alternative is enough. However, there are circumstances where the choice to stop the treatment affects the survival, the safety and/or the quality of life of the patient and the global outcome of the disease in question. When this occurs, drug desensitization can be the answer and should not be viewed as an extravagance, nor the pediatric age should be considered a contraindication. Drug desensitization in children can be safely and successfully performed, having a positive impact on the survival and overall prognosis. In general, the indications for DDS are the same in adults as in children. However, in this age group there are specificities that this paper aimed to describe, reviewing the mechanisms behind drug hypersensitivity and rapid drug desensitization, types of protocols, indications, and contraindications, as well as several technical aspects that are specific to the pediatric age.

Hypersensitivity reactions to chemotherapy: an EAACI Position Paper.

Chemotherapeutic drugs have been widely used in the treatment of cancer disease for about 70 years. The development of new treatments has not hindered their use, and oncologists still prescribe them routinely, alone or in combination with other antineoplastic agents. However, all chemotherapeutic agents can induce hypersensitivity reactions (HSRs), with different incidences depending on the culprit drug. These reactions are the third leading cause of fatal drug-induced anaphylaxis in the United States. In Europe, deaths related to chemotherapy have also been reported. In particular, most reactions are caused by platinum compounds, taxanes, epipodophyllotoxins and asparaginase. Despite their prevalence and relevance, the ideal pathways for diagnosis, treatment and prevention of these reactions are still unclear, and practice remains considerably heterogeneous with vast differences from center to center. Thus, the European Network on Drug Allergy and Drug Allergy Interest Group of the European Academy of Allergy and Clinical Immunology organized a task force to provide data and recommendations regarding the allergological work-up in this field of drug hypersensitivity reactions. This position paper aims to provide consensus on the investigation of HSRs to chemotherapeutic drugs and give practical recommendations for clinicians that treat these patients, such as oncologists, allergologists and internists. Key sections cover risk factors, pathogenesis, symptoms, the role of skin tests, in vitro tests, indications and contraindications of drug provocation tests and desensitization of neoplastic patients with allergic reactions to chemotherapeutic drugs. Statements, recommendations and unmet needs were discussed and proposed at the end of each section.

Allergies and COVID-19 vaccines: An ENDA/EAACI Position paper.

BACKGROUND: Anaphylaxis, which is rare, has been reported after COVID-19 vaccination, but its management is not standardized. METHOD: Members of the European Network for Drug Allergy and the European Academy of Allergy and Clinical Immunology interested in drug allergy participated in an online questionnaire on pre-vaccination screening and management of allergic reactions to COVID-19 vaccines, and literature was analysed. RESULTS: No death due to anaphylaxis to COVID-19 vaccines has been confirmed in scientific literature. Potential allergens, polyethylene glycol (PEG), polysorbate and tromethamine are excipients. The authors propose allergy evaluation of persons with the following histories: 1-anaphylaxis to injectable drug or vaccine containing PEG or derivatives; 2-anaphylaxis to oral/topical PEG containing products; 3-recurrent anaphylaxis of unknown cause; 4-suspected or confirmed allergy to any mRNA vaccine; and 5-confirmed allergy to PEG or derivatives. We recommend a prick-to-prick skin test with the left-over solution in the suspected vaccine vial to avoid waste. Prick test panel should include PEG 4000 or 3500, PEG 2000 and polysorbate 80. The value of in vitro test is arguable. CONCLUSIONS: These recommendations will lead to a better knowledge of the management and mechanisms involved in anaphylaxis to COVID-19 vaccines and enable more people with history of allergy to be vaccinated.

Practice parameters for diagnosing and managing iodinated contrast media hypersensitivity.

Immediate and nonimmediate hypersensitivity reactions to iodinated contrast media (ICM) have been reported to occur in a frequency of about 0.5%-3% of patients receiving nonionic ICM. The diagnosis and management of these patients vary among guidelines published by various national and international scientific societies, with recommendations ranging from avoidance or premedication to drug provocation test. This position paper aims to give recommendations for the management of patients with ICM hypersensitivity reactions and analyze controversies in this area. Skin tests are recommended as the initial step for diagnosing patients with immediate and nonimmediate hypersensitivity reactions; besides, they may also help guide on tolerability of alternatives. Re-exposition or drug provocation test should only be done with skin test-negative ICMs. The decision for performing either re-exposition or drug provocation test needs to be taken based on a risk-benefit analysis. The role of in vitro tests for diagnosis and pretreatment for preventing reactions remains controversial.

Obesity markers in patients with drug allergy and body fat as a predictor.

BACKGROUND: Obesity is a chronic low-grade inflammation state associated with several diseases. OBJECTIVE: To investigate a potential link between drug allergy and obesity, exploring whether the association depends on the type (immediate vs nonimmediate) or the severity of the reaction. METHODS: Anthropometric measurements, bioimpedance, and biochemical analysis, including serum adipokines, were performed in 90 consecutive adult patients studied for suspected drug allergy. Logistic regression models were developed to identify predictors of drug allergy. RESULTS: A total of 84 patients completed the diagnostic workup (78.6% women; mean age 39.58 ± 13.3 years). Drug allergy was confirmed in 39 patients and excluded in 45 (controls). Regarding body mass index, 42.2% had normal weight and 55.3% were overweight/obese. A total of 58% of women and 41% of men fulfilled the criteria for central obesity. Patients with drug allergy exhibited considerably higher body mass index, waist and hip circumferences, waist-hip ratio, fat mass, body fat percentage (BFP), trunk fat mass, leptin levels, and leptin-adiponectin ratio than controls. Similar results were obtained in the subgroup with immediate reactions, compared with the nonimmediate or unknown reactions. The higher the BFP and the number of reactions, the greater the odds of drug allergy (odds ratio [OR], 1.07; 95% confidence interval [CI], 1.01-1.14 and OR, 2.82; 95% CI, 1.31-6.10, respectively). An immediate reaction was also a predictor of drug allergy (OR, 3.81; 95% CI, 1.30-11.14, P = .02), compared with nonimmediate or unknown reactions. In patients with drug allergy, BFP was a predictor of having an immediate reaction (OR, 1.12; 95% CI, 1.02-1.24, P = .02). CONCLUSION: Our study illustrates, for the first time, evidence of a link between obesity and drug allergy, particularly immediate reactions. The BFP emerged as a potential predictor of drug allergy.

Genetic variants associated with T cell-mediated cutaneous adverse drug reactions: A PRISMA-compliant systematic review-An EAACI position paper.

Drug hypersensitivity reactions (DHRs) are associated with high global morbidity and mortality. Cutaneous T cell-mediated reactions classically occur more than 6 hours after drug administration and include life-threatening conditions such as toxic epidermal necrolysis, Stevens-Johnson syndrome, and hypersensitivity syndrome. Over the last 20 years, significant advances have been made in our understanding of the pathogenesis of DHRs with the identification of human leukocyte antigens as predisposing factors. This has led to the development of pharmacogenetic screening tests, such as HLA-B*57:01 in abacavir therapy, which has successfully reduced the incidence of abacavir hypersensitivity reactions. We have completed a PRISMA-compliant systematic review to identify genetic associations that have been reported in DHRs. In total, 105 studies (5554 cases and 123 548 controls) have been included in the review reporting genetic associations with carbamazepine (n = 31), other aromatic antiepileptic drugs (n = 24), abacavir (n = 11), nevirapine (n = 14), trimethoprim-sulfamethoxazole (n = 11), dapsone (n = 4), allopurinol (n = 10), and other drugs (n = 5). The most commonly reported genetic variants associated with DHRs are located in human leukocyte antigen genes and genes involved in drug metabolism pathways. Increasing our understanding of genetic variants that contribute to DHRs will allow us to improve diagnosis, develop new treatments, and predict and prevent DHRs in the future.

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.

A EAACI drug allergy interest group survey on how European allergy specialists deal with ß-lactam allergy.

An accurate diagnosis of ß-lactam (BL) allergy can reduce patient morbidity and mortality. Our aim was to investigate the availability of BL reagents, their use and test procedures in different parts of Europe, as well as any differences in the diagnostic workups for evaluating subjects with BL hypersensitivity. A survey was emailed to all members of the EAACI Drug Allergy Interest Group (DAIG) between February and April 2016, and the questionnaire was meant to study the management of suspected BL hypersensitivity. The questionnaire was emailed to 82 DAIG centres and answered by 57. Amoxicillin alone or combined to clavulanic acid were the most commonly involved BL except in the Danish centre, where penicillin V was the most frequently suspected BL. All centres performed an allergy workup in subjects with histories of hypersensitivity to BL: 53 centres (93%) followed DAIG guidelines, two national guidelines and two local guidelines. However, there were deviations from DAIG recommendations concerning allergy tests, especially drug provocation tests. A significant heterogeneity exists in current practice not only among countries, but also among centres within the same country. This suggests the need to re-evaluate, update and standardize protocols on the management of patients with suspected BL allergy.

Diagnosis and management of drug-induced anaphylaxis in children: An EAACI position paper.

Drug hypersensitivity reactions (DHR) constitute a major and common public health problem, particularly in children. One of the most severe manifestations of DHR is anaphylaxis, which might be associated with a life-threatening risk. During those past decades, anaphylaxis has received particularly a lot of attention and international consensus guidelines have been recently published. Whilst drug-induced anaphylaxis is more commonly reported in adulthood, less is known about the role of drugs in pediatric anaphylaxis. Betalactam antibiotics and non-steroidal anti-inflammatory drugs are the most commonly involved drugs, probably related to high prescription rates. Diagnosis relies on the recognition of symptoms pattern and is based on complete allergic workup, particularly including skin tests and/or specific IgE. However, the real diagnostic value of those tests to diagnose immediate reactions in children remains not well defined for a significant number of the drugs. Generally, a drug provocation test is discussed to confirm or exclude an immediate-onset drug-induced hypersensitivity. Although avoidance of the incriminated drug (and related drug) is the rule, rapid desensitization is useful in selected subgroups of patients. There is a need for large, multicentric studies, to evaluate the real diagnostic value of the currently available skin tests. Moreover there is also a need to develop new diagnostic tests in the future to improve the management of these children.

Desensitization to antibiotics in children.

Drug hypersensitivity reactions can occur to almost all drugs and antibiotics are among the most common cause for this kind of reactions. Drug hypersensitivity may affect any organ or system, and manifestations range widely in clinical severity from mild pruritus to anaphylaxis. In most cases, the suspected drug is avoided in the future. In case of infection, there is usually a safe antibiotic alternative. Nonetheless, in some cases, no alternative treatment exists for optimal therapy. Under these circumstances, desensitization may be performed. Drug desensitization is defined as the induction of a temporary state of tolerance to a drug which can only be maintained by continuous administration of the medication responsible for the hypersensitivity reaction. Desensitization is mainly performed in IgE-mediated reactions. Increasing doses of the implicated drug are administered over a short period of time, until the therapeutic dose is achieved and tolerated. Very few studies confined to children are found in literature. Most of them are case reports. In general, the proposed desensitization schemes are similar to those used in adults differing only in the final dose administered. The purpose of this study is to review desensitization to antibiotics in children presenting and discussing three clinical practical cases of desensitization in this age group.

An experimental biological test to diagnose hypersensitivity reactions to carboplatin: new horizons for an old problem.

Carboplatin, a second-generation platinum compound, is a chemotherapeutic drug effective in many types of cancers. Its use is limited by the development of systemic allergic reactions in up to 30% of the cancer patients. Therefore, it is very important to make a correct diagnosis of true carboplatin allergy, for the crucial clinical implications. In this regard, no biological test is actually available to detect specific immunoglobulin E in the sera of patients allergic to carboplatin. We evaluated a new experimental biological test in patients with suspected immunoglobulin E-mediated reactions to carboplatin. Three patients with suspected hypersensitivity reactions to carboplatin underwent skin tests with an undiluted aliquot (10 mg/ml) of carboplatin preparation planned for infusion. Total serum immunoglobulin E and specific immunoglobulin E to the two platinum salts carboplatin and cisplatin were determined with the ImmunoCAP system (Phadia AB, Uppsala, Sweden). We detected specific immunoglobulin E to carboplatin in all three patients, whereas specific immunoglobulin E to cisplatin was observed in one patient. The positivity of specific immunoglobulin E against carboplatin in these three patients is a new and encouraging observation for the development of a new important instrument that can help clinicians in their therapeutic decisions, after a hypersensitivity reaction to a platinum salt.

Management of adverse reactions induced by chemotherapy drugs.

PURPOSE OF REVIEW: There is a broad spectrum of chemotherapy-induced adverse reactions. Hypersensitivity reactions are being extensively studied as they can affect the ideal treatment. The goal of this review is to describe the current management of adverse reactions to chemotherapy, focusing on hypersensitivity events. RECENT FINDINGS: The range of possible desensitization protocols is increasing, as well as the delabeling algorithms and diagnostic tools. One-bag desensitization protocols, omalizumab use in immediate hypersensitivity reactions, slow desensitization protocols in nonimmediate hypersensitivity reactions and standardization of skin tests for platinum drugs, are some examples. SUMMARY: The handling of adverse reactions to chemotherapy is evolving, with the increasing identification of hypersensitivity reactions and the development of strategies for their management, to maintain the culprit drug.

Dietary parameters in patients with drug allergy: Assessing dietary inflammatory index.

BACKGROUND: Research on the increasing incidence of allergic diseases evidenced the role of diet as a potential key factor. Diet can modulate the low-grade systemic inflammation related to obesity and several diseases. There are no published data on drug allergy. AIM: To investigate a potential association between diet, including dietary inflammatory index (DII), and drug allergy. Also, to evaluate correlations between diet and obesity, inflammatory and metabolic parameters in patients with drug allergy. METHODS: Ninety consecutive patients studied for suspected drug allergy were evaluated in terms of dietary parameters, anthropometric measurements, bioimpedance and biochemical analysis. DII was calculated based on information collected from a food frequency questionnaire. RESULTS: After diagnostic work-up, 39 patients had confirmed drug allergy and 45 excluded, representing the study group and the control group, respectively. The majority (79%) were female, with mean age of 39.58±13.3 years. The 84 subjects revealed an anti-inflammatory diet pattern. No significative difference was found in DII scores between drug allergic patients and controls (-3.37±0.95 vs -3.39±0.86, p = 0.985). However, the patients with drug allergy revealed higher obesity and inflammatory parameters. A significative negative correlation was found between DII and adiponectin levels, in the control group (r = -0.311, p = 0.040). In the patient group, a significative positive correlation was observed between DII and triglycerides (r = 0.359, p = 0.032). No other correlations were found between DII and the assessed parameters. Patients with drug allergy presented a significative higher intake of mono-unsaturated fatty-acids comparing to controls (19.8±3.7 vs 17.8 ± 4.0, p = 0.021). No other statistically significant differences were achieved in dietary parameters, between patients and controls. CONCLUSION: The population assessed in this study revealed an anti-inflammatory diet profile. Although we have found in a previous work that the same patients with drug allergy revealed higher obesity and inflammatory parameters, the DII did not allow to distinguish between patients with drug allergy or controls. The DII scores correlated with triglycerides levels in the drug allergy patients and inversely with adiponectin levels in the control group. Larger studies are needed to clarify the potential role of the diet in drug allergy and its outcomes.

Psychological profiles of patients with suspected drug allergy.

BACKGROUND: Several studies demonstrate an important association between allergic diseases and patients' psychological characteristics. OBJECTIVE: To evaluate any differences in the psychological characteristics of patients studied for suspected drug allergy in comparison with healthy controls. A secondary aim was to assess differences between patients with confirmed versus excluded drug allergy, with respect to the clinical aspects. METHODS: The psychological characteristics of 115 consecutive patients >16 years-old, studied for suspected drug allergy were assessed. They were compared with healthy controls. Four validated questionnaires were used to evaluate anxiety, depression, alexithymia, and personality type. RESULTS: Eighty-eight patients completed the evaluation: 34 had confirmed drug allergy and 33 excluded. Forty-eight healthy subjects filled the 4 questionnaires. Increased neuroticism was associated with increased odds of belonging to the excluded drug allergy group (odds ratio [OR], 1.374; 95% confidence interval [CI], 1.173-1.609). Increased neuroticism (OR, 1.244; 95% CI, 1.065-1.453) and increased anxiety (OR, 1.210; 95% CI, 1.084-1.351) were associated with increased odds of confirmed drug allergy. However, higher extraversion decreased this likelihood (OR, 0.755; 95% CI, 0.643-0.888). The odds of having confirmed drug allergy was reduced by 79.7% (OR, 0.203; 95% CI, 0.060-0.694) for patients with 2 suspected drugs and by 84.6% (OR, 0.154; 95% CI, 0.029-0.809) for those with ≥3 in comparison to those with only one. Patients with moderate to severe reactions were more likely to have confirmed drug allergy (OR, 4.295; 95% CI, 1.105-16.693) than those with milder manifestations. CONCLUSION: Our results highlight that patients with drug allergy have a distinctive psychological profile. Psychological assessment may help to identify patients that would benefit from a targeted intervention.