Previous Hypersensitivity Reactions Research Articles

Safety and oncological effectiveness after desensitization in patients with previous hypersensitivity reactions to chemotherapy.

Taxanes and platinum are first-line treatments in gynecological tumors with high rates of hypersensitivity reactions (HSRs), leading to discontinuation of treatment. Desensitization involves induction of temporary tolerance to previously sensitized medications. The aims of this study are to describe HSRs to paclitaxel and carboplatin and evaluate the safety and effectiveness of desensitization protocols in gynecological cancer patients. Original, retrospective, descriptive, analytical study, approved by Bioethics and Research Committee, included >18-year-old patients with gynecological tumors experiencing HSRs to first-line chemotherapy. Patients underwent 3-bag-12-step desensitization. 174 desensitization (95 paclitaxel, 79 carboplatin) in 33 female patients, mean age 45.5 years (18-71y). Cancer diagnosis: breast 8 (24.2%), ovarian 14 (42.2%), endometrial 2 (6.1%) and cervix 9 (27.2%). HSR occurred in paclitaxel during cycles 1-2 and in carboplatin after 6 cycles. The most frequently seen HSR symptom was cardiovascular with paclitaxel (94.7%), and cutaneous (93.3%) with carboplatin. Three-bags 12-steps desensitization protocol (initial dilution 1:100) in 5.67hrs. All patients reached total dose desensitization: 82% with no reaction, 12% mild, 6% moderate and 0% severe reaction. Mean disease-free interval and progression-free interval in months (m): breast cancer 29 m and 14 m, ovarian 22 m and 9 m, endometrial 40 m and cervical cancer: 67.5 m and 27 m. Twenty-five patients (73.5%) are still alive. HSRs to paclitaxel manifest in the first 1-2 cycles and to carboplatin after 6 cycles. Symptoms include cardiovascular, atypical neuromuscular and urticaria. Changing treatment lines impacts prognosis. Our study revealed that ovarian cancer patients undergoing desensitization protocols achieved longer progression-free intervals. All patients successfully reached total dose desensitization. This study provides evidence of the effectiveness and safety of desensitization and promising perspective for continuing first-line treatment with HSRs.

Infliximab desensitization in patients with inflammatory bowel diseases: a safe therapeutic alternative

Background Hypersensitivity reactions (HSR) to the administration of infliximab (IFX) in Inflammatory Bowel Diseases (IBD) patients are not rare and usually lead to drug discontinuation. We report data on safety and effectiveness of desensitization to IFX in patients with previous HSR. Methods We conducted a retrospective monocentric observational study. Patients for whom a desensitization protocol to IFX was realized after a previous HSR were included. Anti-drug antibodies (ADA) and IFX trough levels at both inclusion and six months after desensitization were collected. Clinical outcomes, including recurrence of HSR were evaluated. Results From 2005 to 2020, 27 patients (Crohn’s Disease: 26 (96%) were included). Desensitization after HSR was performed after a median time of 10.4 months (2.9-33.1). Nineteen (70%) patients received immunosuppressants at time of desensitization. Eight (30%) patients presented HSR at first (n = 2), second (n = 4) or third (n = 2) IFX perfusion after desensitization. None led to intensive care unit transfer or death. Thirteen (48%) had clinical response at 6 months and 8 (29%) were still under IFX treatment two years after desensitization. IFX trough levels and ADA were available for 14 patients at time of desensitization. Most patients (12 out of 14) had ADA at a high level. At 6 months, among the 7 patients with long term response to IFX, 4 presented a decrease of ADA titers and 2 had a significant trough level of IFX. Conclusion IFX desensitization in patients with IBD is a safe therapeutic alternative and represents a potential option for patients refractory to multiple biologics. What is already known? Hypersensitivity reactions to the administration of infliximab is frequent. Occurrence of hypersensitivity reaction, either immediate or delayed, usually leads to permanent drug discontinuation. What is new here? Infliximab desensitization is well tolerated with no hypersensitivity reaction recurrence in 70% of patients. Clinical success at 6 months was of 48% and around a third of patients remained under infliximab therapy two years after desensitization. Antidrug antibodies decreased and infliximab trough levels increased in these patients showing the impact of desensitization on immunogenicity. How can this study help patient care? Infliximab desensitization represents a potential option for patients refractory to multiple biologics who presented hypersensitivity reaction to the drug.

Hypersensitivity Reaction Incidence Patterns and Risk Factors of Iodinated Contrast Media

The subjects of this study were 2,798 patients who experienced hypersensitivity reaction of contrast media among 72,910 who had had iodinated contrast media administered intravenously and CT examination at our hospital. Retrospective survey was conducted with these subjects. Their age, gender, hypersensitivity reaction symptoms, prepare methods for the patients who had previous hypersensitivity reaction of contrast media, and contrast media administered were analyzed. When it came to the hypersensitivity reaction incidence of contrast media, women and patients aged less than 60 had the high risk of the reaction. Even if patients had previous contrast media hypersensitivity reaction, their hypersensitivity reaction incidence risk was reduced as they had an appropriate premedication drug administered and contrast media were changed. Regarding the hypersensitivity reaction incidence rate by contrast media, Iopromide’s hypersensitivity reaction incidence rate was significantly high, whereas Iohexol and Ioversol had low incidence rates. In order to prevent contrast media hypersensitivity reaction recurrence, it is preferentially necessary to change a contrast media to a different one without reuse of causative contrast media, rather than to use a premedication drug only. Along with that, it is necessary to administer a premedication drug.

P515 Infliximab desensitization in patients with Inflammatory Bowel Diseases: a safe therapeutic alternative

Abstract Background Infliximab (IFX) is a humanized monoclonal anti-TNF antibody widely used for the treatment of Inflammatory Bowel Diseases (IBD). Hypersensitivity reactions (HSR) to the administration of the drug are not rare. Their occurrence usually leads to permanent drug discontinuation. We report data on safety and effectiveness of desensitization to IFX in patients with previous HSR. Methods We conducted a retrospective monocentric observational study. Patients for whom a desensitization protocol to IFX was realized after a previous HSR were included. Clinical data on IBD were collected. Anti-drug antibodies (ADA) and IFX trough levels at both inclusion and six months after were collected. Clinical outcome and recurrence of HSR were evaluated. Results From 2005, 27 patients (Female: 18 (66%), Median age at IBD diagnosis: 18.1 (15.6-28.2)) were included. Among these 27 patients, 26 (96%) had Crohn’s Disease, 17 (62%) a history of surgery, 14 (52%) an ileal disease location and 7 (26%) were smokers. It was an immediate HSR in most patients, classified as severe (n=13) or moderate (n=12), and a delayed HSR in only 2 patients. Eleven (41%) patients were treated with immunosuppressants as combination therapy at time of HSR. In most cases (n=18, 66%), HSR occurred at IFX reintroduction after a drug interruption, and in most of these cases after one or two infusions. For 9 (33%) patients, HSR occurred during a maintenance treatment with IFX after a median time of 38 months with 5 moderate and 4 severe reactions. Desensitization was performed after a median time of 10.4 months (2.9-33.1). Nineteen (70%) patients received immunosuppressants as combination therapy. IFX was well tolerated, without recurrence of HSR in 19 (70%) patients, and 12 had a clinical response at 6 months. Eight were still treated with IFX (30%) at 1 year. Eight (30%) patients presented a HSR at first (n=2), second (n=4) or third (n=2) IFX perfusion. Five were moderate with only cutaneous manifestations and 3 were severe. None led to intensive care unit transfer or death. All led to definitive drug discontinuation. Female gender and young age at desensitization were significantly associated with long term continuation of IFX (p=0.05 and p=0.03 respectively). ADA and IFX trough levels were available for 14 patients at time of desensitization. All except 2 had ADA. Among patients who were treated with IFX for a long-term period, 7 had drug levels available at desensitization and 6 months later. All had ADA at baseline. At 6 months, four reduced their level of ADA, 2 had no ADA and a significant trough level of IFX. Conclusion IFX desensitization in patients with IBD is a safe therapeutic alternative and represents a potential option for patients refractory to multiple biologics.

Metal allergy and the use of custom implants in primary total ankle replacement

PurposePatients with metal allergy often go undiagnosed prior to surgery. This can lead to a high rate of complications, especially with orthopedic implants which can be highly variable in the composition of metals used in their production. The purpose of this technique guide is to highlight the use of pre-operative allergy testing in patients with known history of metal allergy, emphasize the proper steps in identifying a potential metal sensitivity reaction, and to report in literature the success of primary custom printed total ankle arthroplasty implants manufactured without the use of traditional metal compositions. Technique guidePatients often have undergone treatment in the past, but nevertheless, discussion about all treatment options, both conservative and surgical should be addressed. The author's preference is to maintain motion in the ankle joint if safe and reasonable. Often times patients will be unaware of metal allergy unless they have had prior reaction, usually from a previous orthopedic surgery. In the cases where the patient does report previous hypersensitivity reaction to metals, referral should then be made to an Allergist for comprehensive metal patch testing or lymphocyte transformation testing. Once the metal limitations are identified, orthopedic industry partner with custom printing capabilities is then contacted. Working with engineers, ankle implants free of offending metals are able to be manufactured. Analysis & discussionTo the author's knowledge, very few cases of metal sensitivity to total ankle replacement exist in the literature. The author's experience to date has shown favorable results when metal allergy is identified, particularly in patients with known history of metal allergy. With proper pre-operative planning and industry partner, good outcomes can be achieved in patients with metal allergy undergoing primary total ankle arthroplasty.

A SUCCESSFUL 4-HOUR ACETYLSALICYLIC ACID DESENSITIZATION PROTOCOL IN AN ATOPIC PATIENT WITH ACUTE CORONARY SYNDROME

<h3>Introduction</h3> Acetylsalicylic acid (ASA) is the world's most widely used drug, essential for treating patients with cardiovascular diseases, in particular acute coronary syndrome (ACS) and chronic ischemic heart disease. ASA and other non-steroidal anti-inflammatory drugs (NSAIDs), especially those that inhibit cyclo-oxygenase-1, can cause hypersensitivity reactions. A history of ASA hypersensitivity typically leads to the avoidance of this potentially lifesaving therapy in patients with coronary artery disease (CAD). ASA desensitization is crucial in patients with ACS and a history of ASA hypersensitivity reactions. <h3>Case Description</h3> A 58-year-old male with a long history of hypertension and unspecified arrythmia was admitted due to acute chest pain. He referred previous hypersensitivity reactions to NSAIDs (ASA, acetaminophen, ibuprofen and metamizole) from hives to angioedema, as well as previous history of allergic rhinitis, fruit-latex syndrome, eosinophilic esophagitis, chronic spontaneous urticaria and angioedema. Initial work-up confirmed the diagnosis of acute myocardial infarction without ST elevation and the patient underwent early coronary angiography with drug-eluting stent placement. Due to previous reactions to ASA and the indication of dual anti-platelet therapy, bedside desensitization was performed including pretreatment with montelukast and cetirizine. The patient successfully completed the oral ASA desensitization protocol in 8 steps, reaching a cumulative dose of 308 mg (Figure 1). Nine months after the procedure the patient continued with 100 mg of ASA daily without adverse reactions. <h3>Discussion</h3> ASA rapid desensitization protocols have proven to be safe and effective in patients with CAD, including ACS, independent of the type of ASA hypersensitivity, reducing associated morbimortality.

Allergy Workup in the Diagnosis of COVID-19 Vaccines-Induced Hypersensitivity Reactions and Its Impact on Vaccination

Introduction: Immediate and delayed hypersensitivity reactions (HSR) to COVID-19 vaccines are rare adverse events that need to be prevented, diagnosed, and managed in order to guarantee adherence to the vaccination campaign. The aims of our study were to stratify the risk of HSR to COVID-19 vaccines and propose alternative strategies to complete the vaccination. Methods: 1,640 subjects were screened for vaccinal eligibility, according to national and international recommendations. Among them, we enrolled for allergy workup 152 subjects, 43 with HSR to COVID-19 vaccines and 109 at high risk of HSR to the first dose. In vivo skin tests with drugs and/or vaccines containing PEG/polysorbates were performed in all of them, using skin prick test and, when negative, intradermal tests. In a subgroup of patients resulted negative to the in vivo skin tests, the programmed dose of COVID-19 vaccine (Pfizer/BioNTech) was administered in graded doses regimen, and detection of neutralizing anti-spike antibodies was performed in these patients after 4 weeks from the vaccination, using the SPIA method. Results: Skin tests for PEG/polysorbates resulted positive in only 3% (5/152) of patients, including 2 with previous HSR to COVID-19 vaccines and 3 at high risk of HSR to the first dose. Among the 147 patients with negative skin tests, 97% (143/147) were eligible for vaccination and 87% (124/143) of them received safely the programmed COVID-19 vaccine dose. Administration of graded doses of Pfizer/BioNTech vaccine were well tolerated in 17 out of 18 patients evaluated; only 1 developed an HSR during the vaccination, less severe than the previous one, and all developed neutralizing anti-spike antibodies after 4 weeks with values comparable to those subjects who received the vaccine in unfractionated dose. Conclusion: On the whole, the usefulness of the skin tests for PEG/polysorbates seems limited in the diagnosis of HSR to COVID-19 vaccines. Graded doses regimen (Pfizer/BioNTech) is a safe and effective alternative strategy to complete the vaccinal course.

Patients with previous immediate hypersensitivity reactions to polyethylene glycol can safely receive the BNT162b2 mRNA COVID-19 vaccine.

Previous anaphylaxis or immediate allergic reaction to polyethylene glycol (PEG; also known as macrogol) is considered a contraindication to the BNT162b2 mRNA COVID‐19 vaccine, which contains 50 ug of PEG at a molecular weight of 2000, and this component is thought to account for the higher rate of anaphylaxis seen with this vaccine (4.7 per million doses) than with other non‐mRNA vaccines. However, there is evidence that both anaphylaxis to PEG and anaphylaxis to the Pfizer COVID‐19 reaction may not be IgE‐mediated, with patients with anaphylaxis to first dose of the Pfizer COVID‐19 vaccine receiving their second dose of vaccine without no or milder reactions in a high‐risk clinic setting. In New Zealand, non‐PEG‐containing COVID‐19 vaccines were not available until late 2021. Therefore, we offered patients with known or suspected PEG anaphylaxis their first dose of Pfizer COVID‐19 vaccine in a high‐risk hospital clinic. Eleven patients with previous hypersensitivity to PEG (including eight with anaphylaxis) successfully received their first dose with mild or no reactions; all have now had their second doses in the community without significant reaction. Record review also showed that most patients with previous hypersensitivity reactions to pegylated asparaginase have also been successfully vaccinated. This demonstrates that previous PEG hypersensitivity, including anaphylaxis, does not exclude immunisation with the Pfizer COVID‐19 vaccine.

Tolerance of the mRNA COVID-19 vaccines in patients with reported taxane reactions

Tolerance of the mRNA COVID-19 vaccines in patients with reported taxane reactions

Aspirin desensitization – how and when?

Aspirin is one of the most commonly used medication in clinical practice, ranking highest among NSAIDs involved in hypersensitivity reactions. Despite the abundance of several therapeutic options, the administration of aspirin is essential both in severe cardiovascular pathology and in pregnancy, particularly in high-risk pregnant women, significantly boosting the survival rate and the quality of life of impacted patients. Desensitization to aspirin may be effective in certain situations. The desensitization approach is tailored to the kind of previous hypersensitivity reaction, the patient's individual risks, and the therapeutic purpose for aspirin therapy.

Preparations of exploration of immediate hypersensitivity to antineoplastic agents: An oncology pharmacy perspective.

Cancer patients are being exposed to antineoplastic drugs more frequently and for longer periods, resulting in a higher risk of hypersensitivity reactions. The aim of this study was to assess the pharmaceutical time and direct cost of drug allergy explorations following immediate hypersensitivity reactions to antineoplastic agents. A micro-costing method was used to collect data on consumption of human and material resources for allergy exploration preparations. The monetisation was carried out on the basis of prices and hourly wage costs applied in 2018. The number and type of allergy explorations prepared by the pharmacy as well as nature of antineoplastic drugs tested, and the number of culprit drugs reintroductions were collected. Almost 1.5 h is required to realise allergy tests for one patient including pharmacist time for prescription analysis and pharmacy technician's time for tests preparation. The mean manufacturing cost of these tests is estimated at €62.87 (€57.82-65.49) per culprit drug for one patient. Programming patients according to culprit drugs tested allows rationalising healthcare provider time and increasing efficiency. From January 2010 to December 2018, 277 patients were tested and 490 allergy explorations were performed, corresponding to more than 5000 preparations. Mostly, the culprit drug could be reintroduced (n = 383, 78.2%) allowing patients to receive the best possible treatment. Management of hypersensitivity reactions is constantly progressing, as it contributes to improving patient care in oncology. This activity is time-consuming for the pharmacy team but allows patients with previous hypersensitivity reaction to continue effective treatment.

Finding the Optimal Alternative for Immediate Hypersensitivity to Low-Osmolar Iodinated Contrast.

Avoiding culprit agents is recommended for subjects who have had previous hypersensitivity reaction (HSR) to low-osmolar contrast media (LOCM). However, the guidelines for choosing optimal alternatives have not been determined. We investigated the outcomes of reexposure in patients with previous immediate HSRs to provide a safe option. The outcomes of reexposure were assessed in a cohort with previous LOCM-associated HSR based on skin testing results and the presence of a common N-(2,3-dihydroxypropyl) carbamoyl side chain. Among 482 skin tests, 38.7% (31/80), 45.8% (99/216), and 64.0% (119/186) of mild, moderate, and severe index HSRs showed positivity to at least 1 LOCM, of which 62.8% showed positivity to at least 2 different LOCM. The overall recurrent HSRs were reduced from 43.8% upon reexposure to the culprit LOCM to 12.3% upon using nonculprit skin test negative LOCM (P = 0.004); those with severe index HSRs exhibited a significant reduction (11.3% vs 100%), but those with non-severe HSRs to LOCM did not. In subjects with severe index HSRs, the skin test cross-reactivity between LOCM was associated with sharing the common side chain (20.7% vs 11.5%, P = 0.003), and the recurrence rate of HSRs was effectively reduced by avoiding the common side chain (24.0% vs 7.8%, P = 0.039). However, these differences were not observed in those with non-severe index HSRs. In patients who experienced a severe index HSR to LOCM, skin test negative LOCM without a common side chain could be suggested as an option for safe reexposure.

Management of Hypersensitivity Reactions to Nondextran Iron Products: New Insights Into Predisposing Risk Factors

Hypersensitivity reactions (HSRs) to non-dextran iron products (NDIPs) are rare, but can manifest with severe signs and symptoms. Predisposing risk factors are not well understood. We aimed to characterize patients with HSRs to NDIPs, with a special focus on possible risk factors. We analyzed clinical characteristics of patients with HSRs to NDIPs referred to our allergy division between 2007 and 2019 compared to tolerant controls, including the type of the eliciting NDIP, severity and characteristics of the HSR, atopy status, history of allergies and urticaria, laboratory and skin test results and outcome of re-exposure with NDIPs. We evaluated the data of 59 patients and 21 controls. Sixteen patients and 4 controls received the NDIP iron sucrose and 41 patients and 15 controls received ferric carboxymaltose. In 2 patients and in 2 controls the culprit NDIP was not known. Twenty-seven patients (46%) experienced an anaphylactic reaction grade I, 15 (25%) a grade II reaction and 17 (29%) a grade III reaction according to Ring and Messmer. Analyzing the history, 22 patients (37%) and 3 controls (14%) reported previous HSRs to other medications. Interestingly, more than half of the patients (n=35, 59%) compared to only 7 controls (33%) reported an episode of any type of urticaria in their previous history. Most patients (n=15; 79%) tolerated re-exposure of an NDIP using a low-reactogenic administration protocol (LRP). A history of drug hypersensitivity and urticaria represent potential risk factors for HSRs to NDIPs. Based on our findings, we propose an algorithm for practical management of patients receiving NDIPs aiming to prevent HSRs.

Empiric Switching of Gadolinium-Based Contrast Agents in Patients With History of Previous Immediate Hypersensitivity Reaction to GBCA: A Prospective Single-Center, Single-Arm Efficacy Trial.

Breakthrough hypersensitivity reactions (HRs) to gadolinium-based contrast agent (GBCA) occur in 40% of patients despite corticosteroid premedication. Other strategies to reduce HRs are not well studied. The aim of this study was to prospectively evaluate HR rate to GBCA among patients with history of HR to GBCA, empirically given an alternative GBCA prior to repeat administration. From September 2019 to September 2020, patients with prior HR to GBCA received 13-hour oral corticosteroid and diphenhydramine premedication prescription with switching of GBCA to gadoterate (previously unavailable at our institution before September 2019). Power analysis (α error, 0.05; β error, 0.80) determined 21 patients were required. Patients were evaluated under a quality assurance waiver from the institutional review board. A radiologist documented the nature of initial HR and inciting GBCA, premedication received, incidence, and severity of breakthrough HR. After exclusions, we evaluated 26 patients with mild (92.3% [24/26]) or moderate (7.7% [2/26]) HR to gadobutrol (53.8% [14/26]), gadoxetate (3.8% [1/26]), and gadopentetate (3.8% [1/26]). In 38.5% (10/26), inciting GBCA was unknown but was likely gadobutrol or gadopentetate based on availability. There were 22 females. The mean patient age was 52.1 ± 15.8 years.From 27 gadoterate administrations, 59.3% (16/27) patients received corticosteroid and diphenhydramine premedication, 11.1% (3/27) received only diphenhydramine, and 29.6% (8/27) with no premedication.Hypersensitivity reaction rate after empiric switching to gadoterate was 3.7% (1 mild reaction; 95% confidence interval [CI], 0.09%-18.9%) overall with no difference in patients with (6.3% [1/16]; 95% CI, 0.15%-28.7%) or without (0%; [0/11] upper bound 95% CI, 25.0%) corticosteroid premedication. In this prospective single-arm study, empirically switching GBCA to gadoterate in patients with prior HR to GBCA substantially reduced the expected rate of subsequent HRs in patients with and without the use of corticosteroid premedication. Empirically switching GBCAs, with or without the use of corticosteroid premedication, can substantially reduce the rate of hypersensitivity breakthrough reactions.

Aspirin Sensitivity in Patients with Moderate to Severe Asthma.

Asthma induced by ingestion of aspirin occurs when symptoms arise within 30 minutes to three hours after aspirin consumption. Previous data indicate that sensitivity to aspirin may be associated with poorly controlled asthma. This study aims to evaluate the frequency of aspirin sensitivity in patients with moderate to severe asthma receiving conventional asthma therapy. This clinical trial was conducted on 65 patients aged 18 to 65 years with moderate to severe asthma from February 2015 to February 2016 at the Allergy Department, Hazrat-e-Rasoul Hospital, Iran University of Medical Sciences, Tehran. To assess treatment responses in patients, forced expiratory volume in the first second (FEV1) and asthma control test (ACT) scores were measuredat baseline and after 3 months. The results of the oral aspirin challenge revealed a prevalence of 35.38% for sensitivity to aspirin. Hypersensitivity reactions to aspirin were detected in 60.9% of the patients with moderate asthma and 39.1% of the patients with severe asthma. All patients with positive aspirin challenge tests suffered from rhinosinusitis and in 56.5% of cases, history of previous hypersensitivity reactions to non-steroidal anti-inflammatory drugs (NSAIDs) was detected. No meaningful differences were found between those patients with aspirin sensitivity and those with aspirin tolerance neither in mean pre-bronchodilator FEV1 nor in ACT scores pre- and post-treatment. To conclude, aspirin sensitivity was not found to have an association with an unfavorable response to conventional treatment in patients with uncontrolled asthma.

Successful Desensitization with Ferric Carboxymaltose

Parenteral iron treatment is used especially in patients who need urgent treatment, have intolerance symptoms to oral iron therapy, and/ or where therapy with oral iron supplementation is insufficient. Allergic reactions can be observed with intravenous iron containing medicines and they should thus only be administered by trained staff with appropriate resuscitation facilities. The European Medicines Agency does not approve the use of intravenous iron-containing products in patients with previous hypersensitivity reactions to other parenteral iron products in its 2013 recommendations to manage the risk of allergic reactions to intravenous iron-containing medicines. However, it may be an option to administer intravenous iron therapy with desensitization in patients who need urgent treatment, who cannot be treated effectively with oral iron preparations, or display intolerance to these products. Here we present the first case of successful ferric carboxymaltose desensitization in a patient who had suffered a prior reaction with the same medicine.

Recent updates of iodinated contrast media hypersensitivity

Previously, immediate reactions to ionic high-osmolar iodinated contrast media (ICM) were regarded as nonimmunological. How ever, despite the use of lower-osmolar ICM, ICM hypersensitivity still occurs in some patients and recent studies suggest that there would be a true allergic response, especially in more severe form. Currently, it is important to identify the sensitized ICM and avoid the agent; however, the usefulness of skin tests and challenge tests has not yet been established, since there are few large-scale studies on them. Although, skin test-negative ICM can be safely used in clinical practice, conflicting results have been reported through various studies, depending on the challenge protocols used. Therefore, standard protocols need to provided. Even if a cul prit agent is not proven by skin tests, its use should be avoided. Reuse of contrast media increases the risk of occurrence of hyper sensitivity reactions. For patients with previous hypersensitivity reactions to contrast media, premedication can help prevent recur rence, but breakthrough in hypersensitivity is not fully achieved by premedication, especially when the previous reaction was a se vere form such as anaphylaxis. Therefore, it is necessary to establish an optimal strategy to choose alternative ICM and premedica tion protocols to prevent recurrence of hypersensitivity reactions to nonionic contrast media. (Allergy Asthma Respir Dis 2020;8:107-113)

Oral desensitization to entecavir: An 11-step protocol

Introduction Chronic hepatitis B infection (CH-B) has a high risk of progression to cirrhosis and hepatocellular carcinoma. Entecavir, a guanosine nucleoside analogue, is often the drug of choice in nucleoside-naive patients with CH-B because of its low rate of viral resistance. Case Description 61-year old Caucasian female with a history of cirrhosis secondary to CH-B who presented to the Allergy clinic with a self-reported allergy to Entecavir. She described a history of unilateral throat swelling, left ankle swelling and worsening of her peripheral neuropathy within 7 days of initiating therapy. Her symptoms presented two hours after oral ingestion of her daily antiviral medication. The acute reaction lasted for six hours and completely resolved three days after discontinuation of the medication. The patient was unable to tolerate one of the alternative medications (tenofovir disoproxil fumarate) due to side effects and the other was cost-prohibited (peg INF-alpha). The patient deferred skin or provocation testing. The patient underwent desensitization protocol (Figure 1) without adverse reactions. Furthermore, she reported no side effects with daily entecavir at her 6-month follow-up. The patient had favorable outcomes evident by normal liver enzymes and hepatitis B e antigen seroconversion at 6 months. Discussion To the best of our knowledge, an oral desensitization protocol for Entecavir has not been reported in the literature. We present a successful desensitization to Entecavir in a patient with a previous hypersensitivity reaction.

Management of Adverse Reactions to Iodinated Contrast Media for Computed Tomography in Korean Referral Hospitals: A Survey Investigation.

ObjectiveTo evaluate the current status of managing adverse reactions to iodinated contrast media (ICM) for computed tomography in referral hospitals in South Korea compared with hospitals in other countries.Materials and MethodsThis survey investigation involved 59 Korean and 15 overseas hospitals using guideline-based questionnaires consisting of 24 items in 7 main categories related to managing adverse reactions to ICM.ResultsInformed written consent with risk factor evaluation was appropriately performed in most of the Korean hospitals. There was considerable variability in assessing renal function across the hospitals; serum creatinine level was used as a reference in 76.4% of Korean hospitals. The Korean hospitals preferred a more stringent approach to determining normal renal function (p = 0.01), withholding metformin (p = 0.01), and fasting before ICM exposure (p < 0.001) compared with overseas hospitals. All the Korean hospitals had an emergency protocol and in-hospital system for adverse reactions to ICM. The Korean (87.7%) and overseas hospitals (100%) were similarly equipped with epinephrine (p = 0.332), but only 38.6% of Korean hospitals were equipped with a bronchodilator (p = 0.004). For patients with a previous hypersensitivity reaction to ICM, 62.3% of Korean hospitals pre-medicated with anti-histamine and corticosteroid according to the severity of the previous reaction, and changed the culprit ICM in 52.8%, while skin test was performed in 17%.ConclusionIn general, Korean referral hospitals were well-prepared regarding informed consent, protocol, and an in-hospital system for managing adverse reactions to ICM. Nevertheless, there was considerable variability in details and management, thus requiring standardization by reflecting current guidelines.

SUCCESSFUL RAPID ORAL DESENSITIZATION TO SULFASALAZINE: A NOVEL 11 STEP PROTOCOL

Introduction Sulfasalazine (SSZ) is usually associated with non-immediate hypersensitivity reactions. Immediate hypersensitivity reactions from sulfasalazine have not been well described. Case Description A 58-year-old female was evaluated for SSZ hypersensitivity reaction. She had a history of inflammatory arthritis with persistent arthralgia despite oral prednisone and methotrexate. The patient had a history of recurrent infections in the setting of hypogammaglobulinemia thus treatment with biologic agents was deferred given concern for worsening hypogammaglobulinemia. SSZ was prescribed 5 years prior for inflammatory arthritis, however, the patient developed bilateral ear pruritus and cough with wheezing within 30 minutes of receiving the drug. The patient deferred skin testing to sulfasalazine. The patient underwent an open oral challenge with 125 mg of SSZ and developed bilateral ear pruritus and coughing within 20 minutes of administration; vital signs were stable without evidence of hypotension. She received antihistamines with resolution of symptoms 40 minutes thereafter. Given that no alternative disease-modifying anti-rheumatic drug was identified, the patient underwent a successful novel 11-step oral desensitization to sulfasalazine 500 mg following pre-medications (Table 1). The patient only developed mild throat pruritus during step 6 without further reactions. The patient has tolerated SSZ without further reactions till date. Discussion Immediate reactions to SSZ are rare and most previous limited number of published desensitization protocols were intended for non-immediate hypersensitivity reactions. We present a successful oral desensitization protocol to SSZ in a patient with a previous immediate hypersensitivity reaction to SSZ which was confirmed by an open oral challenge.