Marina Atanaskovic-Markovic

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

Skin tests are of paramount importance for the evaluation of drug hypersensitivity reactions. Drug skin tests are often not carried out because of lack of concise information on specific test concentrations. The diagnosis of drug allergy is often based on history alone, which is an unreliable indicator of true hypersensitivity.To promote and standardize reproducible skin testing with safe and nonirritant drug concentrations in the clinical practice, the European Network and European Academy of Allergy and Clinical Immunology (EAACI) Interest Group on Drug Allergy has performed a literature search on skin test drug concentration in MEDLINE and EMBASE, reviewed and evaluated the literature in five languages using the GRADE system for quality of evidence and strength of recommendation. Where the literature is poor, we have taken into consideration the collective experience of the group.We recommend drug concentration for skin testing aiming to achieve a specificity of at least 95%. It has been possible to recommend specific drug concentration for betalactam antibiotics, perioperative drugs, heparins, platinum salts and radiocontrast media. For many other drugs, there is insufficient evidence to recommend appropriate drug concentration. There is urgent need for multicentre studies designed to establish and validate drug skin test concentration using standard protocols. For most drugs, sensitivity of skin testing is higher in immediate hypersensitivity compared to nonimmediate hypersensitivity.

Update on the evaluation of hypersensitivity reactions to betalactams

Hypersensitivity reactions to betalactams (BLs) are classified as immediate or nonimmediate. The former usually appear within 1 h of drug‐intake and are mediated by specific IgE‐antibodies. Nonimmediate reactions are those occurring more than 1 h after drug‐intake, and they can be T‐cell mediated. The diagnostic evaluation of allergic reactions to BLs has changed over the last 5 years, for several reasons. Major and minor determinants are no longer commercially available for skin testing in many countries. In immediate allergic reactions, the sensitivity of skin testing and immunoassays is decreasing and new in vitro methods, such as the basophil activation test, are gaining importance for diagnosis. For nonimmediate reactions, skin testing appears to be less sensitive than previous results, although more studies need to be carried out in this direction. Nevertheless, the drug provocation test is still necessary for diagnosis.

Immediate allergic reactions to cephalosporins and penicillins and their cross‐reactivity in children

Penicillins and cephalosporins are the most important betalactams inducing IgE‐mediated reactions. The safety of administering cephalosporins to penicillin‐allergic children is a particular problem, because cephalosporin allergenic determinants have not been properly identified. A study was undertaken to evaluate the frequency of anaphylactic reactions to cephalosporins and penicillins and their cross‐reactivity in a pediatric population. A prospective survey was conducted in a group of 1170 children with suspected immediate allergic reactions to cephalosporins and/or penicillins, which were examined during a period of 8 yr. In vivo (skin tests and challenges) and in vitro tests (for specific IgE) were performed with standard concentration of penicillins and cephalosporins. When 1170 children with a clinical history of allergy to penicillins and/or cephalosporins were tested in vivo for immediate hypersensitivity to betalactams, 58.3% cases overall were found to be skin or challenge test positive. Among them, 94.4% patients were positive to penicillins and 35.3% to cephalosporins. The frequency of positive reactions in the in vivo testing was in the range from 36.4% to 88.1% for penicillins and from 0.3% to 29.2% for cephalosporins. However, 31.5% of the penicillin allergic children cross‐reacted to some cephalosporin. If a child was allergic to a cephalosporin, the frequency of positive reactions to penicillin was 84.2%. The cross‐reactivity between cephalosporins and penicillins varied between 0.3% and 23.9%. The cross‐reactivity among different generations of cephalosporins varied between 0% and 68.8%, being the highest for first and second‐generation cephalosporins and 0% for third generation cephalosporins. The frequency of immediate allergic reactions to cephalosporins is considerably lower compared to penicillins, and the degree of cross‐reactivity between cephalosporins and penicillins depends on the generation of cephalosporins, being higher with earlier generation cephalosporins. The cross‐reactivity among cephalosporins is lower compared to cross‐reactivity between penicillins and cephalosporins.

Drug hypersensitivity in children: report from the pediatric task force of the EAACI Drug Allergy Interest Group

When questioned, about 10% of the parents report suspected hypersensitivity to at least one drug in their children. However, only a few of these reactions can be confirmed as allergic after a diagnostic workup. There is still a lack of knowledge on drug hypersensitivity (DH) epidemiology, clinical spectrum, and appropriate diagnostic methods particularly in children. Meanwhile, the tools used for DH management in adults are applied also for children. Whereas this appears generally acceptable, some aspects of DH and management differ with age. Most reactions in children are still attributed to betalactams. Some manifestations, such as nonsteroidal anti‐inflammatory drug‐associated angioedema and serum sickness‐like reactions, are more frequent among young patients as compared to adults. Risk factors such as viral infections are particularly frequent in children, making the diagnosis challenging. The practicability and validity of skin test and other diagnostic procedures need further assessment in children. This study presents an up‐to‐date review on epidemiology, clinical spectrum, diagnostic tools, and current management of DH in children. A new general algorithm for the study of these reactions in children is proposed. Data are presented focusing on reported differences between pediatric and adult patients, also identifying unmet needs to be addressed in further research.

A matrix effect in pectin-rich fruits hampers digestion of allergen by pepsin in vivo and in vitro

Background It is a general belief that a food allergen should be stable to gastric digestion. Various acidic plant polysaccharides, including pectin, are ubiquitous in fruit matrixes and can form hydrogels under low‐pH conditions.

Tolerability of meropenem in children with IgE‐mediated hypersensitivity to penicillins

Background:  Administration of meropenem to penicillin‐allergic patients who might benefit from this treatment is usually avoided because of a 47.4% rate of cross‐reactivity to imipenem, the prototype of the carbapenem class of β‐lactam antibiotics, demonstrated in a single study on the basis of positive responses to skin tests with imipenem reagents. However, recent studies of ours have demonstrated a very low rate of cross‐reactivity between penicillins and both meropenem and imipenem in adults.

Pharmacovigilance of drug allergy and hypersensitivity using the ENDA-DAHD database and the GALEN platform. The Galenda project.

Nonallergic hypersensitivity and allergic reactions are part of the many different types of adverse drug reactions (ADRs). Databases exist for the collection of ADRs. Spontaneous reporting makes up the core data‐generating system of pharmacovigilance, but there is a large under‐estimation of allergy/hypersensitivity drug reactions. A specific database is therefore required for drug allergy and hypersensitivity using standard operating procedures (SOPs), as the diagnosis of drug allergy/hypersensitivity is difficult and current pharmacovigilance algorithms are insufficient. Although difficult, the diagnosis of drug allergy/hypersensitivity has been standardized by the European Network for Drug Allergy (ENDA) under the aegis of the European Academy of Allergology and Clinical Immunology and SOPs have been published. Based on ENDA and Global Allergy and Asthma European Network (GA2LEN, EU Framework Programme 6) SOPs, a Drug Allergy and Hypersensitivity Database (DAHD®) has been established under FileMaker® Pro 9. It is already available online in many different languages and can be accessed using a personal login. GA2LEN is a European network of 27 partners (16 countries) and 59 collaborating centres (26 countries), which can coordinate and implement the DAHD across Europe. The GA2LEN–ENDA–DAHD platform interacting with a pharmacovigilance network appears to be of great interest for the reporting of allergy/hypersensitivity ADRs in conjunction with other pharmacovigilance instruments.

Allergenic potency of kiwi fruit during fruit development

Abstract Food allergies, including kiwi fruit allergy, have been the subject of extensive research in the last few years. The aim of this study was to examine a possible relationship between the developmental stage of kiwi fruit and its allergenic potency. The protein and allergen patterns of kiwi fruit extracts in September, October, November and December fruit in the period from 2000–2002 were analysed. One of the factors that may contribute to the difficulties in proposing well-defined and standardized fruit extracts should also be the time of fruit harvesting. In this particular case, when the kiwi fruit was edible throughout November and December, we showed discrepancies in allergen content and potencies both in qualitative and quantitative terms. Two major allergens of kiwi fruit, Act c 1 and Act c 2, mainly accounted for the highest allergenic potential of November kiwi extract in vivo and in vitro. Not only the content of major allergens, but also the ratio of different proteins and even isoforms of the same allergen (Act c 2) change with fruit ripening. These findings should be taken into account during preparation of extracts for allergy diagnosis.

Non‐immediate hypersensitivity reactions to beta‐lactam antibiotics in children – our 10‐year experience in allergy work‐up

Non‐immediate reactions to beta‐lactam antibiotics (BL) occur more than one hour after drug administration, and the most common manifestations are maculopapular exanthemas and delayed‐appearing urticaria and/or angioedema. Infections can lead to skin eruptions and mimic drug hypersensitivity reactions (DHR), if a drug is taken at the same time. The most of children are labeled as ‘drug allergic’ after considering only the clinical history.

Interactions of epigallo-catechin 3-gallate and ovalbumin, the major allergen of egg white.

Polyphenols, the potent plant secondary metabolites, have beneficial effects on human health, but the mechanism(s) by which these effects are exerted is not well understood. Here, we present the detailed analysis of the interactions between the major green tea catechin, epigallo-catechin 3-gallate (EGCG), and the major dietary protein and allergen, ovalbumin (OVA). We show that EGCG binds to the pocket that partly overlaps with the previously identified IgE-binding region in OVA, and that this interaction induces structural changes in the allergen. Moreover, our ex vivo studies reveal that OVA binds IgE and stimulates degranulation of basophils, and that its uptake by monocytes proceeds at a slower rate in the presence of EGCG. This study provides further evidence in support of the proposed mechanism by which EGCG interactions with the food allergens contribute to its diverse biological activities and may impair antigen uptake by antigen-presenting cells.