Challenge Testing (challenge + testing)

Distribution by Scientific Domains
Distribution within Medical Sciences


Selected Abstracts


Cross-reactivity among p -amino group compounds in sulfonamide fixed drug eruption: diagnostic value of patch testing

CONTACT DERMATITIS, Issue 2 2004
P. Tornero
We studied 28 patients with fixed drug eruption (FDE) caused by sulfonamide antibiotics to investigate cross-reactivity between sulfonamide derivatives and p -amino compounds and to explore the usefulness of patch testing, as an alternative to controlled oral challenge testing (COCT), in diagnosis within this clinical area. COCT with sulfamethoxazole (SMX), sulfadiazine (SDZ), sulfamethizole (SMZ), furosemide (FU), procaine (PRO) and glipizide (GPZ) was performed. Patch testing (PT) with SMX and SDZ was carried out. In all patients, the diagnosis of FDE was confirmed by positive COCT and allergy to trimethoprim ruled out by COCT. 42.8 and 31.8% of the SMX-induced FDE patients reacted to SMZ and SDZ, respectively. All patients (n = 28) tolerated FU, PRO and GPZ. COCT performed with the 3 sulfonamide antibiotics in 12 patients was positive in 2 subjects with the 3 drugs, in 2 patients only with SMX and SMZ and in the remaining 8, SMX was the only causative drug. PT was positive in 5 of 25 patients positive on COCT. The probability of obtaining a positive PT was higher among patients who had a residual lesion than that among those who lacked this. Cross-reactivity between different sulfonamide antibiotics is thus variable, being most likely between SMX and SMZ. We have found no cross-reactivity between sulfonamide antibiotics and other sulfonamide derivatives or p -amino drugs in FDE. PT is a useful tool in the diagnosis of FDE, especially if there are residual lesions, because it avoided the need for COCT in 20% of patients. [source]


Tetrazepam drug sensitivity , usefulness of the patch test

CONTACT DERMATITIS, Issue 3 2002
C. Pirker
The muscle relaxant tetrazepam may cause severe cutaneous adverse effects. We report 4 cases of varying intensity: Stevens,Johnson syndrome, erythema,multiforme-like exanthema, maculopapular and maculo-urticarial exanthema. Patch testing with tetrazepam (10% in petrolatum) was strongly positive in the 2 patients with severe skin eruptions and weakly positive in the other 2. Oral rechallenge with tetrazepam was positive in 3 patients (1 not done). Diazepam, with a similar chemical structure to tetrazepam, was negative on patch testing and on oral challenge testing in 2 patients. Although the optimal patch test concentration of tetrazepam has still to be determined, it is a useful diagnostic tool to confirm sensitization, particularly in patients with severe bullous eruptions. [source]


Does food allergy cause atopic dermatitis?

DERMATOLOGIC THERAPY, Issue 2 2006
Food challenge testing to dissociate eczematous from immediate reactions
ABSTRACT:, The objective is to evaluate and diagnose, in a controlled setting, suspected food allergy causation in patients hospitalized for management of severe, unremitting atopic dermatitis (AD). Nineteen children were hospitalized at Oregon Health and Science University with atopic dermatitis from 1986 to 2003 for food restriction, then challenge, following standard recommendations. Challenges were prioritized by categories of (a) critical foods (e.g., milk, wheat, egg, soy); (b) important foods; and (c) other suspected foods. Patients were closely observed for evidence of pruritus, eczematous responses, or IgE-mediated reactions. If results were inconsistent, double-blind, placebo-controlled food challenge was performed. A total of 17 children with atopic dermatitis were assessed. Two could not be fully evaluated, thus were excluded from data tabulations. Only one positive eczematous food response was observed of 58 challenges. Three children had well-documented histories of food-induced IgE-mediated anaphylactoid or urticaria reactions to seafood and/or nuts and were not challenged with those foods. Atopic dermatitis, even in the highest-risk patients, is rarely induced by foods. Undocumented assumptions of food causation detract from proper anti-inflammatory management and should be discouraged. Immediate IgE-mediated food reactions are common in atopic dermatitis patients; such reactions are rapid onset, typically detected outside the clinic, and must be distinguished from eczematous reactions. Diagnosis of food-induced eczema cannot be made without food challenge testing. Such tests can be practical and useful for dispelling unrealistic assumptions about food allergy causation of atopic dermatitis. [source]


Adverse events during use of intranasal desmopressin acetate for haemophilia A and von Willebrand disease: a case report and review of 40 patients

HAEMOPHILIA, Issue 1 2000
Dunn
We report our experience with the incidence of adverse events during the use of Stimate® brand intranasal desmopressin acetate (IN DDAVP) for patients with haemophilia A (HA) or von Willebrand disease (vWD) after noting two severe adverse events in one adult patient. All patients with documented vWD (type 1 or 2 A) or haemophilia A (mild, moderate or symptomatic carrier) from the Emory Comprehensive Hemophilia Center who had IN DDAVP challenge testing or were using Stimate® for treatment of bleeding were evaluated for adverse events by patient report or nursing observation of clinical signs and symptoms. Forty patients were studied. Sixty-eight per cent (27/40) experienced clinical signs and/or symptoms. The majority of these symptoms were mild, however several patients reported moderate to severe side-effects and one adult patient required medical intervention for symptomatic hyponatraemia. In our experience, two-thirds of patients tested experienced adverse signs and/or symptoms with the use of Stimate®; considerably higher than that reported from preliminary results in the literature. Young age did not correlate positively with adverse reactions. Severe adverse events requiring medical intervention were rare, however symptoms such as moderate to severe headache, nausea, vomiting and weakness may necessitate evaluation for hyponatraemia. This is the first report of symptomatic hyponatraemia in an adult patient with recommended dosing of Stimate®. Side-effects may be minimized if patients adhere to instructions regarding fluid intake and composition while using IN DDAVP. [source]


Suspected allergy to local anaesthetics: follow-up in 135 cases

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2010
T. HARBOE
Background: Local anaesthetics (LA) are generally considered safe with respect to allergy. However, various clinical reactions steadily occur. Even though most reactions are manifestations of reflexes to perceptive stimuli, uncertainty often remains regarding a possible allergic mechanism. This uncertainty later leads to an avoidance of local anaesthesia and unnecessarily painful interventions, resource-consuming general anaesthesia or even the risk of re-exposure to other yet unidentified allergens. In the present study, follow-up procedures at an allergy clinic were analysed to examine the frequency of identified causative agents and pathogenetic mechanisms and evaluate the strength of the diagnostic conclusions. Method: The medical records of 135 cases with alleged allergic reactions to LA were reviewed. Diagnoses were based on case histories, skin tests, subcutaneous challenge tests and in vitro IgE analyses. Results: Two events (1.5%) were diagnosed as hypersensitivity to LA, articaine,adrenaline and tetracaine,adrenaline, respectively. Ten reactions (7%) were diagnosed as IgE-mediated allergy to other substances including chlorhexidine, latex, triamcinolone and possibly hexaminolevulinate. As challenge testing was not consistently performed with the culprit LA compound, follow-ups were short of definitely refuting hypersensitivity in 61% of the cases. The reported clinical manifestations were in general diagnostically unspecific, but itch and generalised urticaria were most frequent in test-positive cases. Conclusion: Reactions during local anaesthesia are rarely found to be an IgE-mediated LA allergy. Whenever the clinical picture is compatible with allergy, other allergens should also be tested. [source]


MIXTURES OF BEEF TRIPE, BEEF LIVER AND SOYBEANS APPLIED TO FOOD DEVELOPMENT

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 3 2007
L. MALVESTITI
ABSTRACT A nutritive sausage-type product was developed with beef tripe, beef liver and soybeans as ingredients. A three-component mixture design was used to obtain seven different formulations (minimum of each main ingredient: 16.5%, maximum: 67.0%). Ingredients were ground, mixed and packed tightly with a polypropylene film to obtain a roll. Pieces were cooked in boiling water for 90 min. The composition of the obtained products varied within the following ranges: proteins 17.32,25.56 g/100 g, lipids 3.22,3.87 g/100 g, crude fiber 1.50,4.50 g/100 g, minerals 1.44,2.72 g/100 g. Total iron levels varied between 1.39 and 2.98 mg/100 g and calcium levels between 15.07 and 34.01 mg/100 g. Surface response analysis was applied to parameters obtained from texture profile analysis (hardness, adhesiveness, cohesiveness and elasticity). Products hardness increased when the soy content increased; on the contrary, formulations enriched in beef tripe were those of higher elasticity and cohesiveness. Color was mainly determined by the incorporation of liver. A nontrained panel was used to evaluate the acceptance of the different formulations. The most accepted one was that with equal proportions of the three main ingredients. Microbiological challenge testing showed that the thermal treatment was enough for assuring the product safeness even in samples with high initial microbial charge. [source]


A whisper from the silent lung zone

PEDIATRIC PULMONOLOGY, Issue 8 2009
Fatma Aljassim MD
Abstract Multiple breath inert gas washout (MBW) is now regarded as "an insightful, sound, and useful tool to explore the lung and its response to injury in all of its compartments". We describe the important finding of pronounced intra-acinar airways response to indirect challenge testing, detected using MBW but missed by spirometry, in an adolescent with evidence of airway inflammation, and a background of severe respiratory syncytial virus (RSV) infection as an infant. These tests were performed as part of an 18-year follow up of a cohort with severe RSV infection (requiring hospitalization) in the first year of life, and has previously reported significantly higher rates of symptoms of allergic asthma and other features of atopic disease at 13 years in comparison to age matched controls. Small airway dysfunction and ventilation inhomogeneity have emerged as important features of early respiratory disease processes, and this case report provides further evidence supporting its important role in reactive airways disease. Pediatr Pulmonol. 2009; 44:829,832. © 2009 Wiley-Liss, Inc. [source]


Does inhaling menthol affect nasal patency or cough?,

PEDIATRIC PULMONOLOGY, Issue 6 2008
MRCPCH, Priti Kenia MD (Paediatrics)
Abstract Objective There is widespread use of menthol in over-the-counter medications, despite scant information on any beneficial effects. Our aim was to assess the effect of menthol on nasal air flow, perception of nasal patency and cough challenge testing. Materials and Methods Subjects comprised 42 healthy children aged 10 and 11 in a school setting. We used a single-blind pseudo-randomized cross-over trial to compare the effect of an inhalation of either menthol or placebo(eucalyptus oil). Baseline and post-intervention measurements were made on each of 2 consecutive days. Main outcome measures were (i) nasal expiratory and inspiratory flows and volumes, measured by spirometer, (ii) perception of nasal patency, assessed with a visual analogue scale (VAS), and (iii) the number of coughs in response to nebulized citric acid. Results There was no effect of menthol on any of the spirometric measurements. Following menthol, there was a significant increase in the perception of nasal patency (mean difference in log VAS (menthol-placebo),=,,0.207, 95%CI ,0.329, ,0.085). The cough count after menthol inhalation was reduced when compared to baseline but the change was not different from that after placebo (mean difference in cough count (menthol-placebo),=,,1.71, 95%CI ,4.11, 0.69). Conclusion Menthol has no effect on objective measures of flow but significantly increases the perception of nasal patency. It may not be possible to extrapolate these findings to younger children and those with rhinitis. Extending the study of menthol to these groups, including investigations of the efficacy and safety profiles, will provide further valuable evidence for its common use. Pediatr Pulmonol. 2008; 43:532,537. © 2008 Wiley-Liss, Inc. [source]


Airway hyperresponsiveness and acute chest syndrome in children with sickle cell anemia

PEDIATRIC PULMONOLOGY, Issue 3 2007
Karl P. Sylvester PhD
Abstract To determine the occurrence and magnitude of airway hyperresponsiveness (AHR) in children with sickle cell anemia (SCA) who had or had not had acute chest syndrome (ACS) episodes. A subsidiary aim was to determine whether cold air and exercise challenge testing gave similar results in children with SCA. AHR would be greater in SCA children who had had an ACS episode compared to those who had not. Prospective observational study. Forty-two SCA children (median age of 11.5 [range 6.1,16.8] years); 12 children had been previously hospitalized for an ACS episode. AHR was assessed by the change in forced expiratory volume in 1 sec (FEV1) to a cold air challenge and in a subset of the children to an exercise challenge. A positive result to either challenge was deemed to have occurred if the FEV1 fell by at least 10% from the pre-challenge baseline. The magnitude of change in FEV1 following the cold air challenge was similar in children who had or had not had an ACS episode. Six children had a positive response to the cold air challenge (AHR); none had had an ACS hospitalization. Similar proportions of children responded to the cold air and exercise challenge and the magnitude of response to the two tests was similar. Some children, however, responded only to a cold air challenge and others only to an exercise challenge. SCA children who had had an ACS hospitalization episode compared to those who had not were not more likely to respond to a cold air challenge. Importantly, if AHR is to be correctly diagnosed, some SCA children will require to undergo both cold air and exercise challenge testing. Pediatr Pulmonol. 2007; 42:272,276. © 2007 Wiley-Liss, Inc. [source]


Excess of symptoms among radiographers,

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 2 2003
Helen Dimich-Ward PhD
Abstract Background The prevalence and occupational determinants of miscellaneous symptoms referred to as "Darkroom disease" was compared between radiographers and physiotherapists working in British Columbia, Canada. Methods The participation rate for the mailout questionnaire survey was 66.1%. A small subset underwent spirometry and methacholine challenge testing. Results Radiographers had a higher prevalence of most symptoms, with an extreme odds ratio of 11.4 for chemical/metallic taste. The percentage of radiographers with non-specific bronchial hyperresponsiveness (NSBHR) was 3 times higher than that of physiotherapists, although the comparison was not statistically significant. Reporting inadequate ventilation, frequently detecting the odor of X-ray processing chemicals and cleaning up spills within the past 12 months were highly associated with most of the symptoms. Conclusions Our results suggest that differences in the prevalence of symptoms represent a complex process, both in exposure and response to the many constituents found in radiographic processing chemicals. Objective testing of health outcomes and more refined exposure measurements are recommended to further investigate occupational health problems of radiographers. Am. J. Ind. Med. 43: 132,141, 2003. © 2003 Wiley-Liss, Inc. [source]


Resistance and reactance in oscillation lung function reflect basal lung function and bronchial hyperresponsiveness respectively

RESPIROLOGY, Issue 7 2009
Hyeong Yoon KIM
ABSTRACT Background and objective: Currently there are few data available regarding the use of impulse oscillometry parameters to assess airflow obstruction during standardized methacholine challenge testing. Methods: Methacholine challenge tests were performed using impulse oscillometry and conventional spirometry in 64 healthy and 39 asthmatic children, in order to determine airway resistance (R) and reactance (X) at frequencies of 5,35 Hz, as well as FEV1. Results: Baseline R and X were significantly different between the healthy and asthmatic children, with the most discriminating parameter being resistance at 5 Hz (R5). In asthmatic children BHR was well demonstrated by FEV1, X5 and X10, but not by R5. However, when the actual R5 values obtained in this study were compared with the predicted values, there appeared to be differences in the lung function measures that corresponded to varying methacholine concentrations. In addition, the PC20_FEV1 and PC70_X5 were significantly more sensitive than other parameters for methacholine challenge testing. Conclusions: Measuring resistance at 5 Hz using impulse oscillometry facilitates significant differentiation of baseline lung function between asthmatic and healthy children. Additionally, X may be a suitable replacement for PC20 in methacholine challenge testing. [source]


Inflammatory and oxidative stress biomarkers in allergic rhinitis: the effect of smoking

CLINICAL & EXPERIMENTAL ALLERGY, Issue 3 2009
K. Tanou
Summary Background Accumulating evidence confirms the presence of pan-airway inflammation in allergic rhinitis patients. Smoking is known to affect the asthmatic airway inflammation. However, no study has evaluated the impact of smoking on airway inflammation of allergic rhinitis patients. Objective The aim of the present study was to evaluate the impact of smoking on inflammatory and oxidative stress biomarkers in patients with seasonal allergic rhinitis, using non-invasive methods for sample collection. Methods Forty patients with seasonal allergic rhinitis (20 smokers and 20 non-smokers) and 30 healthy subjects (15 smokers and 15 non-smokers) were recruited for the study during pollen season. All subjects were submitted to measurement of the fraction of exhaled NO (FeNO), exhaled breath condensate (EBC) collection, nasal lavage collection, pre- and post- bronchodilation spirometry and metacholine bronchial challenge testing. pH, leukotriene B4 (LTB4) and 8-isoprostane were determined in EBC and nasal lavage samples. Results Patients with allergic rhinitis presented higher LTB4 and 8-isoprostane levels in nasal lavage (P<0.0001 for both comparisons), with no significant differences between smokers and non-smokers. Patients with allergic rhinitis also presented higher LTB4 levels and lower pH in EBC (P<0.001 and P=0.004, respectively), with prominent differences between smokers and non-smokers (P<0.0001 and P=0.003, for LTB4 and pH, respectively). A significant correlation between nasal lavage and EBC LTB4 values was observed (rs=0.313, P=0.048). Conclusions Patients with allergic rhinitis present increased LTB4 and 8-isoprostane in their nasal cavity, however, with no significant differences between smokers and non-smokers. In contrast, smokers with allergic rhinitis present higher LTB4 levels and lower pH in EBC, suggesting that these patients may be more susceptible to the deleterious effects of smoking, compared with non-smokers. [source]


Should children with a history of anaphylaxis to foods undergo challenge testing?

CLINICAL & EXPERIMENTAL ALLERGY, Issue 12 2008
B. J. Vlieg-Boerstra
Summary Background Data on the frequency of resolution of anaphylaxis to foods are not available, but such resolution is generally assumed to be rare. Objective To determine whether the frequency of negative challenge tests in children with a history of anaphylaxis to foods is frequent enough to warrant challenge testing to re-evaluate the diagnosis of anaphylaxis, and to document the safety of this procedure. Methods All children (n=441) who underwent a double-blind, placebo-controlled food challenge (DBPCFC) between January 2003 and March 2007 were screened for symptoms of anaphylaxis to food by history. Anaphylaxis was defined as symptoms and signs of cardiovascular instability, occurring within 2 h after ingestion of the suspected food. Results Twenty-one children were enrolled (median age 6.1 years, range 0.8,14.4). The median time interval between the most recent anaphylactic reaction and the DBPCFC was 4.25 years, range 0.3,12.8. Twenty-one DBPCFCs were performed in 21 children. Eighteen of 21 children were sensitized to the food in question. Six DBPCFCs were negative (29%): three for cows milk, one for egg, one for peanut, and one for wheat. In the positive DBPCFCs, no severe reactions occurred, and epinephrine administration was not required. Conclusions This is the first study using DBPCFCs in a consecutive series of children with a history of anaphylaxis to foods, and no indications in dietary history that the food allergy had been resolved. Our study shows that in such children having specific IgE levels below established cut-off levels reported in other studies predicting positive challenge outcomes, re-evaluation of clinical reactivity to food by DBPCFC should be considered, even when there are no indications in history that anaphylaxis has resolved. DBPCFCs can be performed safely in these children, although there is a potential risk for severe reactions. [source]


Allergy to plant-derived fresh foods in a birch- and ragweed-free area

CLINICAL & EXPERIMENTAL ALLERGY, Issue 10 2000
J. Cuesta-Herranz
Background Allergy to plant-derived fresh foods has often been reported in geographical areas where birch or ragweed pollens are frequent and has been attributed to cross-reactivity to pollens. Objective The aim of this study has been to evaluate allergy to plant-derived fresh foods among pollen-allergic patients from a birch and ragweed-free area. Methods Ninety-five pollen-allergic patients took part in the study. The study consisted of a questionnaire, skin prick tests and challenge tests. Pollen skin tests to five grasses, eight trees and seven weeds were performed in duplicate. Prick tests (prick by prick) and challenge tests were carried out with the fresh foods. Results Most patients allergic to pollens were sensitized to grass (Lolium and Phleum; 97.9%), followed by tree (Olea; 82.1%) and weed pollens (Plantago; 64.2%). 35 of the 95 pollen-allergic patients had positive skin test responses to some plant-derived fresh foods, the highest percentage corresponding to several fruits in the Rosaceae family (peach and pear, 26.3%), followed by Cucurbitacea fruits (melon, 13.7%). The 21.05% of the pollen-allergic patients were allergic to some type of plant-derived fresh food. Peach was the plant-derived fresh food which most frequently elicited allergy symptoms (12.6%), followed by melon (7.36%). The cluster of positive responses to Rosaceae fruits was higher for skin testing than for challenge testing. Conclusion Peach was the most important allergy provoking fruit in a birch and ragweed free-area where apples were consumed at a rate of two times more than peaches and the patients allergic to pollen were principally sensitized to grass pollens. [source]