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Positive Skin Tests (positive + skin_test)
Selected AbstractsAllergy-like reactions to iodinated contrast agents.FUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 3 2005A critical analysis Abstract Allergy-like reactions may occur following administration of iodinated contrast media (CM), mostly in at-risk patients (patients with history of previous reaction, history of allergy, co-treated with interleukin-2 or beta-blockers, etc.) but remain generally unpredictable. Severe and fatal reactions are very rare events. All categories of CM may induce such reactions, although first generation (high osmolar CM) have been found to induce a higher rate of adverse events than low osmolar CM. However, no differences were found between the two categories of CM with respect to mortality. Delayed reactions can also occur. There are no differences between the various categories of CM except for non-ionic dimers, which are more likely to induce such effect. Numerous clinical studies have evaluated the prophylactic value of drugs (mostly antihistamines and corticosteroids). Results are unclear and highly variable. Any prevention depends upon the mechanism involved. However, the mechanism of CM-induced allergy-like reaction remains disputed. Relatively recent data revived the hypothesis of a type-I hypersensitivity mechanism. Positive skin tests to CM have been reported. However, the affinity of IgE towards CM has been found to be very low in the only study which actually evaluated it. Other pathophysiological mechanisms (involving direct secretory effects on mast cells or basophils, or activation of the complement system associated or not with the plasma contact system) are also much debated. Anaphylaxis and anaphylactoid reactions are, in the end, clinically undistinguishable. [source] Skin testing in patients with hypersensitivity reactions to iodinated contrast media , a European multicenter studyALLERGY, Issue 2 2009K. Brockow 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. Methods:, Skin prick, intradermal and patch tests with a series of contrast media were conducted in 220 patients with either immediate or nonimmediate reaction. Positive skin tests were defined according to internationally accepted guidelines. Seventy-one never-exposed subjects and 11 subjects who had tolerated contrast medium exposure, served as negative controls. Results:, Skin test specificity was 96,100%. For tests conducted within the time period from 2 to 6 months after the reaction, up to 50% of immediate reactors and up to 47% of nonimmediate reactors were skin test positive. For immediate reactors, the intradermal tests were the most sensitive, whereas delayed intradermal tests in combination with patch tests were needed for optimal sensitivity in nonimmediate reactors. Contrast medium cross-reactivity was more common in the nonimmediate than in the immediate group. Interestingly, 49% of immediate and 52% of nonimmediate symptoms occurred in previously unexposed patients. Many of these patients were skin test positive, indicating that they were already sensitized at the time of first contrast medium exposure. Conclusions:, These data suggest that at least 50% of hypersensitivity reactions to contrast media are caused by an immunological mechanism. Skin testing appears to be a useful tool for diagnosis of contrast medium allergy and may play an important role in selection of a safe product in previous reactors. [source] Original article: Predictors of response to bronchial allergen challenge in 5- to 6-year-old atopic childrenALLERGY, Issue 4 2007T. A. Douglas Background:, The relationship between atopy and bronchial allergy in young children is not completely understood. Objective:, To examine the association between response to bronchial allergen challenge, immune markers of atopy and other clinical characteristics in 5- to 6-year-old children. Methods:, Children with positive skin test (SPT) to aeroallergen, together with a proportion of SPT negative children (as controls), were recruited from a birth cohort of 198 children at high risk of developing atopic disease and underwent allergen challenge. Results:, Thirty-seven children (26 atopic and 11 SPT negative), median age 74.5 months, were challenged: 31 with house dust mite and six with grass allergen. Only atopic children responded to challenge: n = 12/26 (46%). Wheal size [odds ratio (OR) 2.5 (1.2,5.3), P = 0.01], allergen-specific immunoglobulin E (IgE) [OR 3.4 (1.23,9.61), P = 0.02], total IgE [OR 8.6 (1.1,68.7), P = 0.04], current wheeze [OR 12 (1.7,81.7), P = 0.006] and persistent eczema [OR 11.0 (1.7,68.3), P = 0.006] emerged as the strongest independent predictors of response to allergen challenge. Prediction of response to allergen challenge was significantly improved when immune markers of atopy, and in particular wheal size, were combined with clinical characteristics. Conclusion:, The relationship between atopy and bronchial allergy is quantitative at this age. There may be potential to create more powerful indicators of the presence of respiratory allergy in young children when immunological markers of atopy are considered quantitatively and when combined with clinical history of coexistent allergic disease. [source] Successful carboplatin desensitization in patients with proven carboplatin allergyCANCER, Issue 3 2005Ronit Confino-Cohen M.D. Abstract BACKGROUND Carboplatin is one of the most useful and well tolerated cytotoxic drugs for gynecologic malignancies. Hypersensitivity to carboplatin is not rare among patients receiving multiple recurrent treatments with this drug. The aim of the current study was to offer a safe and convenient carboplatin desensitization strategy to patients with a proven allergic reaction to this drug. METHODS Patients with an immediate objective allergic reaction to carboplatin were skin tested with the drug. A 6-hour carboplatin desensitization protocol was administered to the patients with a carboplatin-positive skin test on each of the following treatment courses. RESULTS Twenty-three patients with an allergic reaction to carboplatin and a positive skin test were included in the current study. Twenty patients (86.9%) were desensitized. One patient developed a mild urticarial rash. Nineteen patients tolerated 80 desensitization courses uneventfully. CONCLUSIONS The data presented a successful desensitization protocol for individuals with a proven allergic reaction to carboplatin. The protocol was safe and convenient and offered an effective therapeutic strategy to patients who required this drug. Cancer 2005. © 2005 American Cancer Society. [source] The effects of allergens in outdoor air on both atopic and nonatopic subjects with airway diseaseALLERGY, Issue 5 2008P. G. J. Burney Background:, Reports on air pollution and asthma exacerbations have been inconsistent, although effects of airborne allergen can be spectacular. With no generalized test for allergen in air, it is not known how far allergen is responsible for nonepidemic exacerbations of the disease. Methods:, Two hundred and ninety-seven patients using bronchodilators aged 18,64 years attending a London practice provided serum samples and were asked to report any acute respiratory events over the coming months. Small particles with a mean aerodynamic diameter <10 ,m (PM10) were collected using a high volume sampler on the roof of the practice. The ability of airborne particles to bind IgE from the patients was compared for particles sampled on the weekend before their reported exacerbation with particles sampled on the weekend 2 weeks before or after. Results:, Exacerbations were associated with a 25% increase in IgE binding to particles collected on the previous weekend compared with the control weekends (95% confidence interval: 10,43%; P = 0.00089). This increase was not higher in patients with positive skin tests or in those sensitized to grass or tree pollens. Conclusions:, Airborne allergen is an important cause of exacerbations even in those with ,intrinsic' asthma. It is important to identify the allergens responsible, as some of these may be controllable. Interpretation of associations of asthma exacerbations with other air pollutants is difficult in the light of these findings. [source] The changing face of food hypersensitivity in an Asian communityCLINICAL & EXPERIMENTAL ALLERGY, Issue 7 2007W. C. Chiang Summary Background Food allergy seems to be increasing in Asia as well as world-wide. Our aim was to characterize food protein sensitization patterns in a population of Asian children with possible food allergy. Methods Children presenting to our allergy clinic over 3 years with symptomatic allergic disease and at least one specific food allergen sensitization documented on skin prick testing were included in the analysis. Results Two hundred and twenty-seven patients fulfilled inclusion criteria. Ninety (40%) of the positive skin tests were positive to egg, 87 (39%) to shellfish, 62 (27.3%) to peanut, 30 (13.2%) to fish, 27 (11.8%) to cow's milk, 21 (9.3%) to sesame, 13 (3.7%) to wheat and eight (3.2%) to soy. Peanut sensitization was the third most common sensitizing allergen, and seen mostly in young atopic children with multiple food hypersensitivities and a family history of atopic dermatitis. The median reported age of first exposure to fish and shellfish was 6 and 12 months, respectively. The mean age at presentation of children with shellfish hypersensitivity was at 6.7 years of age. The likelihood of shellfish sensitization was increased in children with concomitant sensitization to cockroaches. Conclusions In contrast to previously reported low peanut allergy rates in Asia, in our review, peanut sensitization is present in 27% (62/227) of food-allergic children, mostly in patients with multiple food protein sensitizations. Temporal patterns of first exposure of infants to fish and shellfish are unique to the Asian diet. Shellfish are a major sensitizing food source in Asian children, especially in allergic rhinitis patients sensitized to cockroaches. [source] Lack of association between a polymorphism in the interleukin-13 gene and total serum immunoglobulin E level among nuclear families in Costa RicaCLINICAL & EXPERIMENTAL ALLERGY, Issue 3 2002J. C. Celedón Background IL-13 has been implicated in the pathogenesis of asthma and in the regulation of IgE synthesis in humans. Single nucleotide polymorphisms (SNPs) in the IL-13 gene have been associated with asthma and total serum IgE level in Caucasian populations. Objective To test for genetic association between an SNP in exon 4 of the IL-13 gene (IL-13 + 2044 or Arg130Gln) and total serum IgE level and asthma-related phenotypes in a population with high prevalence of asthma living in Costa Rica. Methods Family-based association study. Results Among 83 Costa Rican school children with asthma and their parents (249 individuals), there was no evidence of linkage disequilibrium between the IL-13 + 2044 SNP and any of the outcomes of interest (total serum IgE level on a logarithmic scale, number of positive skin tests to aeroallergens, and asthma). These results were not significantly changed after adjustment for age and gender. Conclusions No significant evidence of linkage disequilibrium between an SNP in exon 4 of the IL-13 gene and total serum IgE level, sensitization to allergens or asthma was found in a family-based association study in Costa Rica. [source] Allergic rhinitis and asthma: epidemiological evidence for the linkCLINICAL & EXPERIMENTAL ALLERGY REVIEWS, Issue 1 2003C. H. Katelaris Summary For years, a clinical relationship between allergic rhinoconjunctivitis (AR/C) and asthma has been observed. Recently, evidence supporting this link has been published. An important body of evidence for a real link between the two conditions has come from epidemiological studies. An increasing prevalence of both conditions is noted in the developed and developing countries. A number of studies have documented the co-existence of AR/C and asthma, with one group reporting up to 80% of patients with asthma having AR/C. Increased bronchial hyperresponsiveness, one of the characteristic findings in asthma, is also demonstrated in those with AR/C even in the absence of clinical asthma. There are a number of common factors linking the two conditions. Atopy is a risk factor for the development of both asthma and AR/C, as is the finding of positive skin tests to common aeroallergens. There is also a well documented temporal relationship between the two conditions, with AR/C beginning soon before or simultaneously with asthma , an association noted in a number of studies examining large groups of subjects . Finally, there are a few studies that demonstrate treatment of one condition leading to an effect on the other , this has been particularly noted with the improvement in asthma control once AR/C has been adequately managed. Given the growing evidence of common factors between the two conditions and the frequent finding that they co-exist in the same patient, management strategies must include treatment of both the upper and the lower airway rather than focusing only on the predominant complaint. [source] | ||||||||||