Werner Aberer

Drug provocation testing in the diagnosis of drug hypersensitivity reactions: general considerations.

A drug provocation test (DPT) is the controlled administration of a drug in order to diagnose drug hypersensitivity reactions. DPTs are performed under medical surveillance, whether this drug is an alternative compound, or structurally/pharmacologically related, or the suspected drug itself. DPT is sometimes termed controlled challenge or reexposure (1), drug challenge (2), graded (2) or incremental challenge (3), test dosing (2), W. Aberer, A. Bircher, A. Romano, M. Blanca, P. Campi, J. Fernandez, K. Brockow, W. J. Pichler, P. Demoly for ENDA, and the EAACI interest group on drug hypersensitivity Department of Environmental Dermatology, University of Graz, Graz, Austria; Department of Dermatology, Basle, Switzerland; Allergy Service, Catholic University of Rome, Italy; Allergy Service, University La Paz, Madrid, Spain; Clinic for Allergy and Immunology, Florence, Italy; Allergy Section, Dept. Clin. Med., UMH, Elche, Spain; Klinik und Poliklinik f1r Dermatologie und Allergologie, Muenchen, Germany; Clinic for Rheumatology and Clinical Immunology/Allergology, Inselspital, Bern, Switzerland; Maladies Respiratoires-INSERM U454, H7pital Arnaud de Villeneuve, Montpellier, France

Diagnosis of immediate allergic reactions to beta-lactam antibiotics

Allergic reactions to betalactams are the most common cause of adverse drug reactions mediated by specific immunological mechanisms. Reactions may be induced by all betalactams currently available, ranging from benzylpenicillin (BP) to other more recently introduced betalactams, such as aztreonam or the related betalactamase-inhibitor clavulanic acid (Fig. 1) (1–5). Although the production process of betalactams has improved over the years, the number of reactions has not decreased, M. J. Torres, M. Blanca, J. Fernandez, A. Romano, A. de Weck, W. Aberer, K. Brockow, W. J. Pichler, P. Demoly for ENDA, and the EAACI interest group on drug hypersensitivity Allergy Service, Carlos Haya Hospital, Malaga, Spain; Allergy Service, University La Paz, Madrid, Spain; Allergy Section, Dept. Clin. Med., UMH, Elche, Spain; Allergy Service, Catholic University of Rome, Italy; Fondation Gerimmun, Beaumont 18, CH1700, Fribourg, Switzerland; Department of Environmental Dermatology, Graz, Austria; Klinik und Poliklinik f5r Dermatologie und Allergologie, Muenchen, Germany; Clinic for Rheumatology and Clinical Immunology/Allergy, Inselspital, Bern, Switzerland; Maladies Respiratoires-INSERM U454, Hopital Arnaud de Villeneuve, Montpellier, France

Icatibant, a New Bradykinin-Receptor Antagonist, in Hereditary Angioedema

BACKGROUND Hereditary angioedema is characterized by recurrent attacks of angioedema of the skin, larynx, and gastrointestinal tract. Bradykinin is the key mediator of symptoms. Icatibant is a selective bradykinin B2 receptor antagonist. METHODS In two double-blind, randomized, multicenter trials, we evaluated the effect of icatibant in patients with hereditary angioedema presenting with cutaneous or abdominal attacks. In the For Angioedema Subcutaneous Treatment (FAST) 1 trial, patients received either icatibant or placebo; in FAST-2, patients received either icatibant or oral tranexamic acid, at a dose of 3 g daily for 2 days. Icatibant was given once, subcutaneously, at a dose of 30 mg. The primary end point was the median time to clinically significant relief of symptoms. RESULTS A total of 56 and 74 patients underwent randomization in the FAST-1 and FAST-2 trials, respectively. The primary end point was reached in 2.5 hours with icatibant versus 4.6 hours with placebo in the FAST-1 trial (P=0.14) and in 2.0 hours with icatibant versus 12.0 hours with tranexamic acid in the FAST-2 trial (P<0.001). In the FAST-1 study, 3 recipients of icatibant and 13 recipients of placebo needed treatment with rescue medication. The median time to first improvement of symptoms, as assessed by patients and by investigators, was significantly shorter with icatibant in both trials. No icatibant-related serious adverse events were reported. CONCLUSIONS In patients with hereditary angioedema having acute attacks, we found a significant benefit of icatibant as compared with tranexamic acid in one trial and a nonsignificant benefit of icatibant as compared with placebo in the other trial with regard to the primary end point. The early use of rescue medication may have obscured the benefit of icatibant in the placebo trial. (Funded by Jerini; ClinicalTrials.gov numbers, NCT00097695 and NCT00500656.)

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.

National rates and regional differences in sensitization to allergens of the standard series-Population-adjusted frequencies of sensitization (PAFS) in 40,000 patients from a multicenter study (IVDK)

Sensitization rates to contact allergens vary between centers and are influenced by sex and age. Eliminating the latter 2 factors by standardization of data by age and sex, the present analysis address possible differences between centers remaining after elimination of these confounders, and analyzes other factors which might influence rates, e.g. the MOAHL index. Overall standardized rates were well within the range reported in previous studies and may be regarded as representing the rates of the “patch test population” in Central Europe (e.g. nickel sulfate 12.9%, fragrance mix 10.5″. balsam of Peru 7.3%. thimerosal 5.6%). For this analysis, data of those departments which contributed more than 2000 patients or of those with extreme proportion concerning sex, age and occupational cases were selected. Patients from these 10 departments differed considerably will regard to the items of the MOAHL index and with regard to standardized rates. The items of the MOAHL index proved to be suitable for describing different patch test populations and for explaining some differences between centers. Only ‘atopic dermatitis’ seems to have little influence on (standardized) rates. Face dermatitis is not yet represented in the MOAHL index, but should be included, together with age > 40 years, in an extended index (acronym: MOAHLFA). Regional allergen exposure (with striking differences between East Germany, West Germany and to a lesser extent Austria) seems to have a great influence on the sensitization pattern observed in a department. In addition, sociological factors may influence sensitization rates, which is exemplified by high rates of nickel allergy in a socially delined subgroup. Future studies should focus on these factors, as well as on factors concerning patch test practices and quality control.

Classification, diagnosis, and approach to treatment for angioedema: consensus report from the Hereditary Angioedema International Working Group

Angioedema is defined as localized and self‐limiting edema of the subcutaneous and submucosal tissue, due to a temporary increase in vascular permeability caused by the release of vasoactive mediator(s). When angioedema recurs without significant wheals, the patient should be diagnosed to have angioedema as a distinct disease. In the absence of accepted classification, different types of angioedema are not uniquely identified. For this reason, the European Academy of Allergy and Clinical Immunology gave its patronage to a consensus conference aimed at classifying angioedema. Four types of acquired and three types of hereditary angioedema were identified as separate forms from the analysis of the literature and were presented in detail at the meeting. Here, we summarize the analysis of the data and the resulting classification of angioedema.

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.

Predictors of severe systemic anaphylactic reactions in patients with Hymenoptera venom allergy: Importance of baseline serum tryptase—a study of the European Academy of Allergology and Clinical Immunology Interest Group on Insect Venom Hypersensitivity

BACKGROUND Severe anaphylaxis to honeybee or vespid stings is associated with a variety of risk factors, which are poorly defined. OBJECTIVE Our aim was to evaluate the association of baseline serum tryptase concentrations and other variables routinely recorded during patient evaluation with the frequency of past severe anaphylaxis after a field sting. METHODS In this observational multicenter study, we enrolled 962 patients with established bee or vespid venom allergy who had a systemic reaction after a field sting. Data were collected on tryptase concentration, age, sex, culprit insect, cardiovascular medication, and the number of preceding minor systemic reactions before the index field sting. A severe reaction was defined as anaphylactic shock, loss of consciousness, or cardiopulmonary arrest. The index sting was defined as the hitherto first, most severe systemic field-sting reaction. Relative rates were calculated with generalized additive models. RESULTS Two hundred six (21.4%) patients had a severe anaphylactic reaction after a field sting. The frequency of this event increased significantly with higher tryptase concentrations (nonlinear association). Other factors significantly associated with severe reactions after a field sting were vespid venom allergy, older age, male sex, angiotensin-converting enzyme inhibitor medication, and 1 or more preceding field stings with a less severe systemic reaction. CONCLUSION In patients with honeybee or vespid venom allergy, baseline serum tryptase concentrations are associated with the risk for severe anaphylactic reactions. Preventive measures should include substitution of angiotensin-converting enzyme inhibitors.

Skin testing in patients with hypersensitivity reactions to iodinated contrast media - a European multicenter study.

Background:  Iodinated contrast media cause both immediate and nonimmediate hypersensitivity reactions. The aim of this prospective study was to determine the specificity and sensitivity of skin tests in patients who have experienced such reactions.

Management of chronic hand eczema

Hand eczema (HE) is one of the most frequent skin diseases and has often a chronically relapsing course with a poor prognosis resulting in a high social and economic impact for the individual and the society. In this article, we highlight the results of an expert workshop on the ‘management of severe chronic hand eczema’ with the focus on the epidemiology, the burden of severe HE, its classification and diagnostic procedures, and the current status of treatment options according to an evidence‐based approach (randomized controlled clinical trials, RCTs). We conclude that despite the abundance of topical and systemic treatment options, disease management in patients with severe chronic HE is frequently inadequate. There is a strong need for RCTs of existing and new treatment options based on clearly diagnosed subtypes of HE and its severity.