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.

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.

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.

Prevalence of abacavir-associated hypersensitivity syndrome and HLA-B*5701 allele in a Portuguese HIV-positive population.

BACKGROUND: Human Immunodeficiency Virus (HIV)-positive patients treated with the antiretroviral drug abacavir (ABC) may develop a potentially fatal ABC-associated hypersensitivity syndrome (ABC-HS), typically characterized by fever, malaise, rash, vomiting/diarrhoea and/or dyspnoea/cough. ABC-HS has been strongly associated with HLA-B*57:01 carriage and screening for this allele is recommended. OBJECTIVE: To determine the prevalence of HLA-B*57:01 and to characterize suspected ABC-HS in the adult HIV population from our hospital during a 7-year period. METHODS: Clinical data on patients under ABC treatment from January 2006 to December 2012 were analyzed to search for symptoms of ABC-HS. Reactions of suspected ABC-HS were characterized. HLA-B*57:01 and patch tests (1% and 10% ABC in petrolatum) with readings at 48 h were performed in those without previous testing. From January 2008 routine HLA-B*57:01 screening was implemented. RESULTS: From January 2006 to December 2007, 186 patients began treatment with ABC (data from 163 were available): 7 (4%) patients stopped ABC for suspected ABC-HS (71% males, median age 45 years) and the median time for onset of the reaction after starting ABC was 7 days. Four of the 7 patients had the HLA-B*57:01 allele and 2 of these 4 had positive patch tests. After HLA-B*57:01 screening implementation (January 2008), 573 patients were evaluated and 35 (6.1%) were HLA-B*57:01 positive; no suspected ABC-HS were observed since then. CONCLUSION: Four patients with suspected ABC-HS (of 6 screened) were HLA-B*57:01 positive. No ABC-HS occurred since January 2008, after HLA-B*57:01 screening was implemented.

Hypersensitivity reaction and tolerance induction to ethambutol.

Tuberculosis remains the leading cause of death worldwide from any infectious agent and the alarming increase in the annual incidence of new cases has been described as a global emergency. Mycobacterium infection requires simultaneous administration of multiple drugs. Although the majority of treatment courses progress with minor side effects, adverse reactions to antituberculosis drugs occur in about 5% of treated patients and can be responsible for cessation or switching the therapy. Both nonimmediate (mostly maculopapular rash) and immediate reactions (urticarial reactions) have been described with these drugs. The main problem is the occurrence of reactions while the patient is on treatment with multiple drugs. The diagnosis of the culprit drug is mostly based on stopping all medication, followed by the reintroduction of each drug with a time interval of four to five days. An alternative drug should be the first approach if it is equally effective. Most of the times, none of the alternative drugs are as effective as the culprit. If this is the case, a desensitization procedure should be performed. The authors describe a case of a woman with Mycobacterium avium complex (MAC) infection, to whom treatment with ethambutol was crucial to recovery, and present a modified desensitization protocol to this drug.