M. J. Torres

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.

Hypersensitivity to nonsteroidal anti‐inflammatory drugs (NSAIDs) – classification, diagnosis and management: review of the EAACI/ENDA# and GA2LEN/HANNA*

To cite this article: Kowalski ML, Makowska JS, Blanca M, Bavbek S, Bochenek G, Bousquet J, Bousquet P, Celik G, Demoly P, Gomes ER, Niżankowska‐Mogilnicka E, Romano A, Sanchez‐Borges M, Sanz M, Torres MJ, De Weck A, Szczeklik A, Brockow K. Hypersensitivity to nonsteroidal anti‐inflammatory drugs (NSAIDs) – classification, diagnosis and management: Review of the EAACI/ENDA and GA2LEN/HANNA. Allergy 2011; 66: 818–829.

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.

Diagnosis of nonimmediate reactions to beta-lactam antibiotics.

Nonimmediate manifestations (i.e. occurring more than 1 h after drug administration), particularly maculopapular and urticarial eruptions, are common during β‐lactam treatment. The mechanisms involved in most nonimmediate reactions seem to be heterogeneous and are not yet completely understood. However, clinical and immunohistological studies, as well as analysis of drug‐specific T‐cell clones obtained from the circulating blood and the skin, suggest that a type‐IV (cell‐mediated) pathogenic mechanism may be involved in some nonimmediate reactions such as maculopapular or bullous rashes and acute generalized exanthematous pustulosis. In the diagnostic work‐up, the patients history is fundamental; patch testing is useful, together with delayed‐reading intradermal testing. The latter appears to be somewhat more sensitive than patch testing, but also less specific. In case of negative allergologic tests, consideration should be given to provocation tests, and the careful administration of the suspect agents. With regard to in vitro tests, the lymphocyte transformation test may contribute to the identification of the responsible drug.

Classification and practical approach to the diagnosis and management of hypersensitivity to nonsteroidal anti-inflammatory drugs.

Hypersensitivity reactions to aspirin (acetylsalicylic acid) and other nonsteroidal anti‐inflammatory drugs (NSAIDs) constitute only a subset of all adverse reactions to these drugs, but due to their severity pose a significant burden to patients and are a challenge to the allergist. In susceptible individuals, NSAIDs induce a wide spectrum of hypersensitivity reactions with various timing, organ manifestations, and severity, involving either immunological (allergic) or nonimmunological mechanisms. Proper classification of reactions based on clinical manifestations and suspected mechanism is a prerequisite for the implementation of rational diagnostic procedures and adequate patient management. This document, prepared by a panel of experts from the European Academy of Allergy and Clinical Immunology Task Force on NSAIDs Hypersensitivity, aims at reviewing the current knowledge in the field and proposes uniform definitions and clinically useful classification of hypersensitivity reactions to NSAIDs. The document proposes also practical algorithms for the diagnosis of specific types of NSAIDs hypersensitivity (which include drug provocations, skin testing and in vitro testing) and provides, when data are available, evidence‐based recommendations for the management of hypersensitive patients, including drug avoidance and drug desensitization.

Clinical evaluation of Pharmacia CAP System™ RAST FEIA amoxicilloyl and benzylpenicilloyl in patients with penicillin allergy

Background: The diagnosis of IgE‐mediated immediate reactions to penicillins can be supported by in vivo or in vitro tests using classical benzylpenicillin determinants. The wide variety of β‐lactams and the description of new specificities requires a re‐evaluation of the different tests available. The objective was to evaluate the diagnostic capacity of Pharmacia CAP System™ RAST FEIA amoxicilloyl c6 (AXO) and benzylpenicilloyl c1 (BPO) in patients with a documented IgE‐mediated penicillin allergy.

General considerations on rapid desensitization for drug hypersensitivity - a consensus statement.

To cite this article: Cernadas JR, Brockow K, Romano A, Aberer W, Torres MJ, Bircher A, Campi P, Sanz ML, Castells M, Demoly P, Pichler WJ, for the European Network of Drug Allergy and the EAACI interest group on drug hypersensitivity. General considerations on rapid desensitization for drug hypersensitivity – a consensus statement. Allergy 2010; 65: 1357–1366.

Characteristics of subjects experiencing hypersensitivity to non-steroidal anti-inflammatory drugs: patterns of response

Background Non‐steroidal anti‐inflammatory drugs (NSAIDs) are one of the most frequently involved groups of medicines in hypersensitivity drug reactions. Two mechanisms can induce the reaction: immunological (sensitization) due to a specific IgE or T cell response and pharmacological (cyclooxygenase inhibition). The contribution of each of these mechanisms to the reactions is not well known.

The diagnostic interpretation of basophil activation test in immediate allergic reactions to betalactams

Background Basophil activation by allergens, including drugs, has been used to determine sensitivity and to study IgE recognition and cross‐reactivity.

Relevance of the determination of serum‐specific IgE antibodies in the diagnosis of immediate β‐lactam allergy

Background:  Allergic reactions to β‐lactams are the most frequent cause of adverse drug reactions mediated by specific immunologic mechanisms. They can be explored by in vivo and/or in vitro tests. The measurement of serum‐specific immunoglobulin E (IgE) presents several advantages: safety, simplicity, and availability to nonallergologist physicians.