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.

Intraoperative anaphylaxis: a case report of allergy to ranitidine.

We report the case of a 18-year old male who developed intraoperative anaphylaxis. The presence of specific IgE to ranitidine was documented This case confirms the possibility of anaphylaxis at first exposure.

Cross reactivity between European hornet and yellow jacket venoms.

BACKGROUND: Cross-reactions between venoms may be responsible for multiple diagnostic positivities in hymenoptera allergy. There is limited data on the cross-reactivity between Vespula spp and Vespa crabro, which is an important cause of severe reactions in some parts of Europe. We studied by CAP-inhibition assays and immunoblotting the cross-reactivity between the two venoms. METHODS: Sera from patients with non discriminative skin/CAP positivity to both Vespula and Vespa crabro were collected for the analyses. Inhibition assays were carried out with a CAP method, incubating the sera separately with both venoms and subsequently measuring the specific IgE to venoms themselves. Immunoblotting was performed on sera with ambiguous results at the CAP-inhibition. RESULTS: Seventeen patients had a severe reaction after Vespa crabro sting and proved skin and CAP positive also to vespula. In 11/17 patients, Vespula venom completely inhibited IgE binding to VC venom, whereas VC venom inhibited binding to Vespula venom only partially (<75%). In 6 subjects the CAP-inhibition provided inconclusive results and their sera were analysed by immunoblotting. The SDS-PAGE identified hyaluronidase, phospholipase A1 and antigen 5 as the main proteins of the venoms. In 5 sera the levels of IgE against antigen 5 of Vespa crabro were higher than IgE against Vespula germanica, thus indicating a true sensitisation to crabro. CONCLUSION: In the case of multiple positivities to Vespa crabro and Vespula spp the CAP inhibition is helpful in detecting the cross-reactivities.

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

Drug hypersensitivity reactions can occur with most drugs, are unpredictable, may affect any organ or system, and range widely in clinical severity from mild pruritus to anaphylaxis. In most cases, the suspected drug is avoided in the future. However, for certain patients, the particular drug may be essential for optimal therapy. Under these circumstances, desensitization may be performed. Drug desensitization is defined as the induction of a temporary state of tolerance of a compound responsible for a hypersensitivity reaction. It is performed by administering increasing doses of the medication concerned over a short period of time (from several hours to a few days) until the total cumulative therapeutic dose is achieved and tolerated. It is a high-risk procedure used only in patients in whom alternatives are less effective or not available after a positive risk/benefit analysis. Desensitization protocols have been developed and are used in patients with allergic reactions to antibiotics (mainly penicillin), insulins, sulfonamides, chemotherapeutic and biologic agents, and many other drugs. Desensitization is mainly performed in IgE-mediated reactions, but also in reactions where drug-specific IgE have not been demonstrated. Desensitization induces a temporary tolerant state, which can only be maintained by continuous administration of the medication. Thus, for treatments like chemotherapy, which have an average interval of 4 weeks between cycles, the procedure must be repeated for every new course. In this paper, some background information on rapid desensitization procedures is provided. We define the drugs and drug reactions indicated for such procedures, describe the possible mechanism of action, and discuss the indications and contraindications. The data should serve as background information for a database (accessible via the EAACI-homepage) with standardized protocols for rapid desensitization for antibiotics, chemotherapeutic agents, monoclonal antibodies/fusion proteins, and other drugs.

Diagnosis of immediate-type beta-lactam allergy in vitro by flow-cytometric basophil activation test and sulfidoleukotriene production: a multicenter study.

INTRODUCTION: This multicenter study aimed to evaluate the diagnostic value of 2 cellular tests based on basophil reactivity--the basophil activation test (BAT, Flow-CAST) and the sulfidoleukotriene release assay (CAST-ELISA)--in immediate-type beta-lactam allergy, particularly in patients with a clinical history of allergy and a negative skin test result. MATERIAL AND METHODS: In a multicenter study encompassing 10 European centers, 181 patients with a history of immediate-type beta-lactam allergy, and 81 controls, we evaluated the diagnostic efficiency of specific IgE determinations and of 2 cellular tests based on basophil reactivity, the BAT and the sulfidoleukotriene release assay. RESULTS: With Flow-CAST, sensitivity varied for individual beta-lactam allergens from 16% for penicilloyl-polylysine to 33% for amoxicillin, reaching 50% when all 5 allergens were considered. In beta-lactam-allergic patients with negative skin test results (22.8%), Flow-CAST showed positive results for at least 1 of the 5 allergens in 37%. Specificity varied from 89% to 97%, depending on the allergens used. In CAST-ELISA, the overall sensitivity in skin test-positive patients was 41.7%; in patients with negative skin test results it was 27.9%. Both tests were not absolutely correlated, so that when all the results were considered together, sensitivity increased to 64.3% and specificity varied for both tests combined from 73% to 92%. In contrast, specific IgE determinations in the same population yielded a lower sensitivity (28.3%). CONCLUSIONS: A diagnostic algorithm including skin tests and specific IgE, followed by cellular tests in negative patients and controlled challenge enabled us to confirm beta-lactam allergy in 92% of cases. This procedure would also allow us to avoid two-thirds of the required controlled challenges.

Correlation between atopy and hypersensitivity reactions during therapy with three different TNF-alpha blocking agents in rheumatoid arthritis.

OBJECTIVE: The use of TNF-alpha antagon-ists (infliximab, etanercept, adalimumab) has changed the course of many rheumatic diseases including rheumatoid arthritis (RA). Since their approval, some questions regarding their safety have been raised. Both acute and delayed reactions have been described. METHODS: The aim of our work was to detect if there is a different incidence of hypersensitivity reactions - infusion reactions to infliximab or injection site reactions with etanercept or adalimumab - in atopic patients versus non- atopic patients. In 90 patients (82 females, 8 males) with rheumatoid arthritis we evaluated, during the first year of therapy with three different TNF-alpha blocking agents, total serum IgE (normal value <100 KU/L) (method ImmunoCAP PHADIA) and serum specific IgE performing a qualitative multi-allergen test for inhal-ant allergens (PHADIATOP, method ImmunoCAP PHADIA). In all patients we evaluated injection site reactions (ISR) to etanercept and adalimumab - erythema, edema and itching at the site of subcutaneous administration - and infusion reactions to infliximab - hypotension/hypertension, chest pain, dyspnea, laryngospasm, fever, urticaria angioedema. RESULTS: We obtained the following results: patients with high value of tot-al IgE were 15/90 (16.6 %), patients with total IgE in normal range were 75/90 (83.4.%), reactions in patients with high total IgE were 6.7% and in patients with normal total IgE were 18.7% (p=0.255 ns). As regards serum specific IgE, patients with specific IgE were 17/90 (18.8%) patients without specific IgE were 73/90 (81.2%), reactions in patients with specific IgE were 11.8% and in patients without specific IgE were 17.8% (p=0.547 ns). Also, when the data were divided for the three groups, the differences were not statistically significant. CONCLUSION: Adverse reactions to biological agents have been categorized into five types. In hypersensitivity reactions - the Beta type reactions - an immune mechanism is suspected. Our data showed that there was no correlation between the atopic status and the incidence of hypersensitivity reactions during the first year of therapy with three different TNF-alpha blocking agents.

Pharmacoeconomics of subcutaneous allergen immunotherapy.

The current burden of allergic diseases, estimated by both direct and indirect costs, is very relevant. In fact the cost estimation for rhinitis amount globally to 4-10 billion dollars/year in the U.S. and to an average annual cost of 1089 euros per child/adolescent and 1543 euros per adult in Europe. The estimated annual costs in Northern America for asthma amounted to 14 billion dollars. Consequently, preventive strategies aimed at reducing the clinical severity of allergy are potentially able to reduce its costs. Among them, specific immunotherapy (SIT) joins to the preventive capacity the carryover effect once treatment is discontinued. A number of studies, mainly conducted in the US and Germany demonstrated a favourable cost-benefit balance. In the nineties, most surveys on patients with allergic rhinitis and asthma reported significant reductions of the direct and indirect costs in subjects treated with SIT compared to those treated with symptomatic drugs. This is fully confirmed in recent studies conducted in European countries: in Denmark the direct cost per patient/year of the standard care was more than halved following SIT; in Italy a study on Parietaria allergic patients demonstrated a significant difference in favor of SIT plus drug treatment for three years versus drug treatment alone, with a cost reduction starting from the 2nd year and increasing to 48% at the 3rd year, with a highly statistical significance which was maintained up to the 6th year, i.e. 3 years after stopping immunotherapy, corresponding to a net saving for each patient at the final evaluation of 623 euros per year; in France a cost/efficacy analysis comparing SIT and current symptomatic treatment in adults and children with dust mite and pollen allergy showed remarkable savings with SIT for both allergies in adults and children.

Economic evaluation of sublingual immunotherapy: an analysis of literature.

Allergic rhinitis and asthma constitute a global health problem because of their very high prevalence and the consequent burden of disease, concerning medical and economical issues. Among the treatments of allergy, specific immunotherapy has the capacity to favourably alter the natural history of the disease both during and after its performance and thus to reduce the direct and indirect costs of allergic rhinitis and asthma. A number of studies reported such cost reduction for traditional, subcutaneous immunotherapy and recent data demonstrate that also sublingual immunotherapy (SLIT) is associated to economic advantages and/or monetary savings, specifically in terms of reduction of disease economic burden. Only few formal economic assessments of SLIT have been carried out so far, this article will present and discuss the published studies addressed to this issue. The data obtained, although the number of studies is still limited, provide preliminary evidence supporting a SLIT effect on sparing costs for respiratory allergy.

European Polistes venom allergy.

The American Polistes species venom mixture--that of P. annularis, P. fuscatus, P. metricus and P. exclamans--was the only commercially available mixture for diagnosis and therapy until 1996. However, these species of Polistes are not present in Europe, where P. dominulus and P. gallicus and to a lesser extent P. nimphus are widespread. The aim of this study was to assess the allergenic differences among the commercial American mix, P. dominulus and P. gallicus venom in European patients and therefore to verify if this mixture is suitable for diagnosis in these patients. We carried out skin tests, radioallergosorbent tests (RAST) and RAST inhibition in Italian patients with adverse reactions to Polistes stings. RAST inhibition results demonstrated that cross-reactivity between the American and European species is only partial and that P. dominulus and P. gallicus venoms have exclusive allergens. Skin tests and direct RAST confirmed these results and also showed that European Polistes venom is more suitable than the American mix in Italian patients. Moreover, we found a high rate of cross-reactivity between P. dominulus and P. gallicus. To conclude, P. dominulus and/or P. gallicus venoms are necessary for diagnosis and therefore in the therapy of European patients.

Practice parameters for sublingual immunotherapy.

The efficacy and safety of sublingual immunotherapy (SLIT) are currently supported by clinical trials, meta-analysis and post-marketing surveys. Practice parameters for clinical use of SLIT are proposed here by a panel of Italian specialists, with reference to evidence based criteria. Indications to SLIT include allergic rhinoconjunctivitis, asthma, and isolated conjunctivitis (strength of recommendation: grade A). As to severity of the disease, SLIT is indicated in moderate/severe intermittent rhinitis, persistent rhinitis and mild to moderate asthma (grade D). SLIT may be safely prescribed also in children aged three to five years (grade B), and its use in subjects aged more than 60 years is not prevented when the indications and contraindication are ascertained (grade D). The choice of the allergen to be employed for SLIT should be made in accordance with the combination of clinical history and results of skin prick tests (grade D). Polysensitisation, i.e. the occurrence of multiple positive response does not exclude SLIT, which may be done with the clinically most important allergens (grade D). As to practical administration, co-seasonal, pre co-seasonal, and continuous schedules are available, being the latter recommended for perennial allergens or for pollens with particularly prolonged pollination, such as Parietaria (grade D). For pollens with relatively short pollination, such as grasses and trees (cypress, birch, alder, hazelnut, olive) the pre co-seasonal and perennial schedules are preferred (grade C). The build-up phases suggested by manufacturers can be safely used (grade A), but they can be modified according to the patient's tolerance (grade C). A duration of SLIT of 3-5 years is recommended to ensure a long-lasting clinical effect after the treatment has been terminated (grade C).

A case of fatal biphasic anaphylaxis secondary to multiple stings: adrenalin and/or a longer observation time could have saved the patient?

We report the case of an atopic male, 76 years old, with post-myocardial infarction ischaemic cardiopathy, arterial hypertension and a history of insect-sting induced large local reactions who died because of a biphasic anaphylaxis subsequent to multiple Vespid stings (about 15). Within approximately ten minutes after the stings he developed urticaria, extended erythema and hypotension (90/60 mmHg), measured by a family member. The objective physical examination by the emergency doctor at the patient's home revealed an orticarioid reaction and erythema of the back and neck, an unaffected respiratory apparatus and CNS, normal pupils, a pulse rate of 74, normal blood pressure ranging from 120/70 to 130/60 mmHg. The patient was administered antihistamine and corticosteroid through parenteral route. During the 45' observation period at the patient's home the urticaria subsided but not to completion. Approximately 40 minutes after the emergency doctor left, the urticaria reoccurred, angioedema of the neck and worsening asthenia developed. The patient died, despite attempts to resuscitate him by the emergency doctor that had been called out again. A post-mortem examination revealed generalised eodema of the lungs, brain, glottis, and bowels due to the severe characteristic systemic compromise of anaphylaxis. The Authors discuss whether an early use of adrenalin and/or a longer observation time could have saved the patient.

Infiltrating cells and related cytokines in lesional skin of patients with chronic idiopathic urticaria and positive autologous serum skin test.

In approximately one-third of patients with chronic idiopathic urticaria (CIU), autoantibodies against the high-affinity IgE receptor and/ or against IgE can be detected and a wheal-and-flare response can be provoked by the intradermal injection of autologous serum (ASST). In this study we aimed to further characterize the inflammatory response observed in the subgroup of CIU patients with positive ASST and serum-evoked histamine-release in vitro from basophils in comparison with unaffected skin and healthy donors. An immunohistochemical analysis of infiltrating cells (CD4, MPO, EG1, EG2, tryptase), cytokines (IL-4, IL-5, IFN-gamma), chemokines and chemokine receptors (IL-8, CCR3, CXCR3), and adhesion molecules (ICAM-1, VCAM-1, ELAM-1) was performed on seven selected patients (four males and three females; median age: 45 years; range: 22-57) and five healthy donors. Cytokine evaluation was also performed in five psoriatic patients to obtain an additional control. In spontaneous wheals we observed an increased number of CD4+ T lymphocytes when compared with the controls, and an increased number of neutrophils and eosinophils, whereas mast cells did not show a significant variation. A significant expression for IL-4 and IL-5 could only be observed in lesional skin, while IFN-gamma showed a slight expression in the same site. Chemokine receptors CCR3 and CXCR3 did not show a defined polarized response in either lesional or unaffected skin. An increased expression of all cellular adhesion molecules (CAMs) studied was detected in spontaneous wheals. The lack of a significant difference in the expression of tryptase + mast cells, T lymphocytes, IL-8, CXCR3 and CCR3, a few CAMs between the lesional and unaffected skin of CIU patients suggests a wide immunological activation that involves not only lesional tissues, but possibly extends to the whole of the skin's immune system.

An epidemiological survey on the allergological importance of some emerging pollens in Italy.

Epidemiological studies on the pollens responsible for allergic diseases throughout Italy are lacking. Routine diagnostic panels consist prevalently of grass, Parietaria, weeds, birch, olive and mugwort. Considering the great variety of Italian geographical areas and the observation of the growing allergological importance of new botanical species (e.g., ambrosia), a survey on pollen species considered "minor" was necessary. A panel of "emerging" pollens (birch, hazelnut, alder, hornbeam, cypress, ragweed) and a routine panel were used to skin prick test 2,934 consecutive outpatients with respiratory pathology of suspected allergic origin, in 21 centers across Italy. A specific questionnaire was compiled. It was found that 20.1% of patients did not react to allergens tested, 28.2% were positive for at least one emerging pollen and 51.7% did not react to emerging pollens but tested positive for at least one allergen from the routine panel. The prevalence of single pollen species was related to geographical areas. Ragweed pollen was shown to provoke asthma much more frequently than other pollens. Hitherto scarcely considered pollens play a considerable role in causing allergic diseases in Italy. In the great majority of patients, positivity for these pollens was associated with positivity to the better recognized group of pollen allergens, although in some cases they were the primary pathogenic agent. We suggest that these more recently considered allergens be included in routine diagnostic panels.