Positive Oral Challenge Research Articles

Rash decisions: Unmasking a risk phenotype in adults with persistent delayed penicillin allergy sensitized during historic infection with Epstein-Barr virus

BackgroundPenicillin-associated exanthems in the setting of infectious mononucleosis (IM) caused by Epstein-Barr virus (EBV) are often viewed as a transient event, and not a true allergy. Recent evidence challenges this and suggest a notable subset of patients retain penicillin hypersensitivity. ObjectiveWe investigated the occurrence and predictors of persistent adulthood hypersensitivity in those with a penicillin-associated rash occurring in the setting of EBV infection. MethodRetrospective analysis of patients referred for penicillin allergy testing to an Australian tertiary hospital captured from 2015 to 2023 was carried out. ResultsOf 2,066 patients, 23 (1%) had a penicillin-associated rash during an historic EBV infection; 16 (70%) female, median 18 years (interquartile range [IQR] 16-20) at index reaction, median 38 years (IQR 33.5-57) when allergy tested. Skin-prick and delayed-intradermal testing (D-IDT) to a penicillin panel were performed and oral provocation challenge in those testing negative. Persistent sensitisation was shown in 6/23 (26%); 4/6 (67%) positive D-IDT, 3/6 (50%) positive oral challenge. Notably, 5/6 (83%) had a severe maculopapular exanthem (sMPE) with facial swelling, including 2/6 (33%) with probable drug reaction with eosinophilia and systemic symptoms (DRESS) during the index reaction, compared with 0/17 (0%) in patients tolerating penicillin on re-exposure. ConclusionThis study highlights the requirement of allergy testing in adult patients reporting a penicillin-associated sMPE in the setting of EBV, even if occurring during childhood or adolescence.

Oral food challenge in children with contact urticaria in reaction to cow's milk.

To evaluate the relationship between the occurrence of contact urticaria in reaction to cow's milk in infants and the diagnosis of cow's milk allergy (CMA) established by supervised oral food challenge. In this cross-sectional study, we identified 184 children who had undergone 221 oral food challenge (OFC) at a CMA reference center between July 2015 and August 2019. Of these, 23 (12.5%) had a history of contact urticaria to cow's milk and underwent a total of 30 OFC. Baked cow's milk OFC were excluded, and 21 children were included in the study. All data from clinical history and allergy tests (serum-specific IgE dosages and skin prick test [SPT] with reconstituted cow's milk formula) were recorded on standardized forms. The challenge was conducted with reconstituted cow's milk formula in increasing volumes every 15-20 min. 24 OFC were performed; 13/24 (54.2%) for diagnostic purpose and 11/24 (45.8%) to evaluate cow's milk tolerance. Allergy tests were positive in 14 patients (87.5%). Positive oral challenge outcomes were identified in 7/24. One patient had a late flare of atopic dermatitis and five children presented with immediate urticaria (two generalized urticaria and three perioral urticaria). The median papule diameter was 6.5 mm in patients with a positive OFC and 3.75 mm in the negative group (P = 0.02). The occurrence of contact urticaria might be the only manifestation among infants sensitized to cow's milk with tolerance to oral ingestion. Reactions due to oral challenge were related to a larger wheal diameter on the SPT.

Efficacy of a Clinical Decision Rule to Enable Direct Oral Challenge in Patients With Low-Risk Penicillin Allergy

Fewer than 5% of patients labeled with a penicillin allergy are truly allergic. The standard of care to remove the penicillin allergy label in adults is specialized testing involving prick and intradermal skin testing followed by an oral challenge with penicillin. Skin testing is resource intensive, limits practice to specialist-trained physicians, and restricts the global population who could undergo penicillin allergy delabeling. To determine whether a direct oral penicillin challenge is noninferior to the standard of care of penicillin skin testing followed by an oral challenge in patients with a low-risk penicillin allergy. This parallel, 2-arm, noninferiority, open-label, multicenter, international randomized clinical trial occurred in 6 specialized centers, 3 in North America (US and Canada) and 3 in Australia, from June 18, 2021, to December 2, 2022. Eligible adults had a PEN-FAST score lower than 3. PEN-FAST is a prospectively derived and internationally validated clinical decision rule that enables point-of-care risk assessment for adults reporting penicillin allergies. Patients were randomly assigned to either direct oral challenge with penicillin (intervention arm) or a standard-of-care arm of penicillin skin testing followed by oral challenge with penicillin (control arm). The primary outcome was a physician-verified positive immune-mediated oral penicillin challenge within 1 hour postintervention in the intention-to-treat population. Noninferiority was achieved if a 1-sided 95% CI of the risk difference (RD) did not exceed 5 percentage points (pp). A total of 382 adults were randomized, with 377 patients (median [IQR] age, 51 [35-65] years; 247 [65.5%] female) included in the analysis: 187 in the intervention group and 190 in the control group. Most patients had a PEN-FAST score of 0 or 1. The primary outcome occurred in 1 patient (0.5%) in the intervention group and 1 patient (0.5%) in the control group, with an RD of 0.0084 pp (90% CI, -1.22 to 1.24 pp). The 1-sided 95% CI was below the noninferiority margin of 5 pp. In the 5 days following the oral penicillin challenge, 9 immune-mediated adverse events were recorded in the intervention group and 10 in the control group (RD, -0.45 pp; 95% CI, -4.87 to 3.96 pp). No serious adverse events occurred. In this randomized clinical trial, direct oral penicillin challenge in patients with a low-risk penicillin allergy was noninferior compared with standard-of-care skin testing followed by oral challenge. In patients with a low-risk history, direct oral penicillin challenge is a safe procedure to facilitate the removal of a penicillin allergy label. ClinicalTrials.gov Identifier: NCT04454229.

Reactions to peanut at first introduction in infancy are associated with age ≥8 months and severity of eczema.

Previous studies have shown the efficacy of the early introduction of peanut to prevent peanut allergy. Due to the exclusion of infants with sensitization to peanut, it remains unclear what the optimal timing of introduction is. The PeanutNL study was performed in 6 pediatric allergology centers in the Netherlands. Infants referred for the clinical early introduction of peanut to prevent peanut allergy underwent skin prick tests for peanut and an oral peanut challenge at a median age of 6 months. One hundred sixty two of 707 infants (23%) who had never eaten peanut before were sensitized to peanut, of which 80 (49%) had wheals of >4 mm. Sixty seven of 707 infants (9.5%) had a positive oral challenge to peanut at first introduction. Multivariate analysis revealed that age (p < .001) and SCORAD eczema severity scores (p = .001) were significant risk factors. Introduction of peanut at ≥8 months in infants with moderate and severe eczema resulted in an increased risk (odds ratio 5.24 (p = .013) and 3.61 (p = .019), respectively) of having reactions to peanut as compared to introduction before 8 months. A family history of peanut allergy and previous reactions to egg were not identified as independent risk factors. These results suggest that peanut should be introduced before the age of 8 months to reduce the risk of reactions at first exposure in infants with moderate and severe eczema. Furthermore, since children with severe eczema have the highest risk of reactions, the clinical introduction of peanut should be considered, at the latest at the age of 7 months.

IMPLEMENTING A REFERRAL PROTOCOL FOR PENICILLIN ALLERGY TESTING OF PREGNANT WOMEN

<h3>Introduction</h3> Recent American College of Obstetrics and Gynecology (ACOG) guidelines advocate for the safety of penicillin allergy testing in pregnant women. Penicillin allergy de-labeling allows for preferred peripartum antibiotic therapy for Group B Streptococcus (GBS) prophylaxis and reduces IV antibiotics and neonatal ICU (NICU) care for newborns. Yet, there remains widespread hesitance to perform penicillin allergy testing on pregnant women. <h3>Methods</h3> This is a prospective cohort study. We developed a single-academic center referral protocol for pregnant patients with penicillin allergy to be evaluated by allergy and immunology (A/I) prior to delivery. The primary endpoint is rate of penicillin allergy de-labeling. Secondary endpoints included use of intrapartum antibiotics for GBS prophylaxis in the mother and IV antibiotic use in the neonates. <h3>Results</h3> The study is ongoing, and to-date we have seen 18 pregnant women in A/I clinic for penicillin allergy evaluation. Thirteen patients completed allergy testing. Of these, 11 (85%) were de-labeled and two experienced positive amoxicillin oral challenge (one delayed rash and one immediate possibly IgE-mediated symptom). Six patients have delivered, one was GBS-positive and successfully received preferred penicillin (ampicillin) for intrapartum prophylaxis without event. <h3>Conclusion</h3> Implementing a referral pathway directly from the obstetrics clinic for penicillin allergy evaluation is a streamlined method to potentially remove penicillin allergy labels in pregnant patients prior to delivery. In our study, the majority of patients were successfully de-labeled. Further data is needed to assess safety outcomes as well as use of alternative antibiotics and need for IV antibiotics in the neonate.

Successful Milk Oral Immunotherapy Promotes Generation of Casein-Specific CD137+ FOXP3+ Regulatory T Cells Detectable in Peripheral Blood

BackgroundOral immunotherapy (OIT) is an emerging treatment for cow’s milk protein (CMP) allergy in children. The mechanisms driving tolerance following OIT are not well understood. Regulatory T cells (TREG) cells are key inhibitors of allergic responses and promoters of allergen-specific tolerance. In an exploratory study, we sought to detect induction of allergen-specific TREG in a cohort of subjects undergoing OIT.MethodsPediatric patients with a history of allergic reaction to cow’s milk and a positive Skin Pick Test (SPT) and/or CMP-specific IgE >0.35 kU, as well as a positive oral challenge to CMP underwent OIT with escalating doses of milk and were followed for up to 6 months. At specific milestones during the dose escalation and maintenance phases, casein-specific CD4+ T cells were expanded from patient blood by culturing unfractionated PBMCs with casein in vitro. The CD4+ T cell phenotypes were quantified by flow cytometry.ResultsOur culture system induced activated casein-specific FOXP3+Helios+ TREG cells and FOXP3- TEFF cells, discriminated by expression of CD137 (4-1BB) and CD154 (CD40L) respectively. The frequency of casein-specific TREG cells increased significantly with escalating doses of milk during OIT while casein-specific TEFF cell frequencies remained constant. Moreover, expanded casein-specific TREG cells expressed higher levels of FOXP3 compared to polyclonal TREG cells, suggesting a more robust TREG phenotype. The induction of casein-specific TREG cells increased with successful CMP desensitization and correlated with increased frequencies of casein-specific Th1 cells among OIT subjects. The level of casein-specific TREG cells negatively correlated with the time required to reach the maintenance phase of desensitization.ConclusionsOverall, effective CMP-OIT successfully promoted the expansion of casein-specific, functionally-stable FOXP3+ TREG cells while mitigating Th2 responses in children receiving OIT. Our exploratory study proposes that an in vitro TREG response to casein may correlate with the time to reach maintenance in CMP-OIT.

Delayed corticosteroid hypersensitivity: a clinical management proposal.

Background. Different clinical pictures are related to corticosteroids (CS) non immediate hypersensitivity and the frequency of these reactions can be underestimated. The classification of CS in 3 groups and the identification of two patient's profiles has been proposed by Baeck to help clinicians in the management of these cases. Methods. Data of 14 patients with clinical history of delayed reactions to various CS and positive skin test and/or oral challenge are retrospectively analyzed. Results. Three different patterns of patients are identified evaluating history, clinical picture and tests results. The first one (6 pts, 43%) is characterized by cutaneous and/or mucosal reaction due to inhaled Budesonide and patch test positive only to topical molecules belonging to the group 1 of CS. The second pattern (4 pts) has clinical history of local and systemic skin reactions to the topic and parenteral administration of the same or other steroid drugs. Patients belonging to the third pattern (4 pts) have a history of systemic reactions to general administration of CS without previous contact reaction. Pattern 2 and 3 show a wide sensitization to molecules belonging to the 3 groups of CS. All the patients show patch test positive to Budesonide. Conclusions. Although the lack of standardization, the allergy workup proves useful to differentiate patients sensitized to one or few molecules from polysensitized and to identify the culprit drugs. Intradermal and challenge test are necessary to complete the diagnostic workup. The results suggest the possibility of a different management of patients. Patients of pattern one can be only patch tested with a limited series of CS belonging to the 3 groups. They don't need an extensive exclusion of steroids use. The pattern 2 and 3 must be submitted instead to a complete allergological individual evaluation to identify alternative tolerated drugs, because of the risk of systemic reactions. The Baeck's classification shows limited usefulness in these cases.

Polyethylene Glycol–Induced Systemic Allergic Reactions (Anaphylaxis)

Polyethylene glycols (PEGs) or macrogols are hydrophilic polymers found in everyday products such as foods, cosmetics, and medications. We present 5 cases of confirmed PEG allergy, which to our knowledge is the largest case series to date. Four of the 5 cases developed anaphylaxis to medications containing PEGs, with 1 near-fatal case resulting in cardiac arrest. Skin tests were undertaken to the index medications and to PEGs of different molecular weights. Three were confirmed with positive skin prick test result to PEG, 1 confirmed with a positive intradermal test result, and 1 confirmed after positive oral challenge. Two patients developed anaphylaxis following intradermal test to PEG and 1 a systemic allergic reaction (without hypotension or respiratory distress) following PEG skin prick tests. Before diagnosis, all 5 patients were mislabeled as allergic to multiple medications and their clinical management had become increasingly challenging. An algorithm is proposed to safely investigate suspected PEG allergy, with guidance on PEG molecular weights and skin test dilutions to minimize the risk of systemic allergic reaction. Investigation carries considerable risk without knowledge and informed planning so should only be conducted in a specialist drug allergy center.

CONTINUOUS LIKELIHOOD RATIOS TO PREDICT THE PROBABILITY OF A PEANUT REACTION

Introduction Peanut-specific IgE (PsIgE) is used to predict the probability of a reaction using likelihood ratios (LR) which convert pretest to posttest probabilities. While dichotomous (positive or negative) LRs are defined using a cutoff of 0.35, it is better to use a continuous LR which corresponds to each value of PsIgE. This is particularly important when there is only a PsIgE and no history of prior ingestion to rely on. Methods PsIgEs were measured and oral peanut challenges performed on 58 children ages 9 months to 18 years. An ROC curve was determined using SPSS. The slope of the ROC curve, which is the likelihood ratio for each value of PsIgE, was determined by differentiated the ROC curve and used to convert sIgEs to likelood ratios. Results PsIgE ranged from 0 to 23. There were 33 negative and 25 positive oral challenges. The area under the ROC curve was 0.71 (p Conclusions Continuous LRs can provide a more accurate assessment of the probability of a peanut reaction for a given sIgE when the history of peanut ingestion is not known. Additional data points will refine these estimates.

Feasibility of desensitizing children highly allergic to peanut by high-dose oral immunotherapy.

There are limited data on the feasibility, efficacy and safety of high-dose oral immunotherapy (OIT) in children highly allergic to peanuts. In children highly allergic to peanut, we primarily aimed to determine the feasibility of reaching the maximum maintenance dose (MMD) of 5000mg peanut protein or, alternatively, a lower individual maintenance dose (IMD), by OIT up-dosing. Secondarily, we aimed to identify adverse events (AEs) and determine factors associated with reaching a maintenance dose. The TAKE-AWAY peanut OIT trial enrolled 77 children 5-15years old, with a positive oral peanut challenge. Fifty-seven were randomized to OIT with biweekly dose step-up until reaching MMD or IMD and 20 to observation only. Demographic and biological characteristics, AEs, medication and protocol deviations were explored for associations with reaching maintenance dose. All children had anaphylaxis defined by objective symptoms in minimum two organ systems during baseline challenge. The MMD was reached by 21.1%, while 54.4% reached an IMD of median (minimum, maximum) 2700 (250, 4000) mg peanut protein, whereas 24.5% discontinued OIT. During up-dosing, 19.4% experienced anaphylaxis. Not reaching the MMD was caused by distaste for peanuts (66.7%), unacceptable AEs (26.7%) and social reasons (6.7%). Increased peanut s-IgG4 /s-IgE ratio (OR [95% CI]: 1.02 [1.00, 1.04]) was associated with reaching MMD. Although 75.5% of children with peanut anaphylaxis reached a maintenance dose of 0.25-5g, only 21.1% reached the MMD. Distaste for peanuts and AEs, including high risk of anaphylaxis, limited the feasibility of reaching MMD.

Dietary Habits in Patients with Chronic Spontaneous Urticaria: Evaluation of Food as Trigger of Symptoms Exacerbation.

Background Many patients with chronic spontaneous urticaria (CSU) identify different foods as triggers of their symptoms and frequently make dietary restrictions without enough information. Objective To explore the diet habits of CSU patients and estimate the clinical impact of the foods most frequently reported to be suspect. Methodology Patients were interrogated about their clinical history of urticaria. Skin prick test and sIgE serum were done for most frequently reported foods by patients. Food challenge test was also performed. A group of healthy subjects was included to compare the dietary habits and the results of the diagnostic tests. Results Patients with CSU (n 245) and healthy (n 127) subjects were included. 164 (66%) subjects from CSU group and 31 (24%) from the control group reported at least one adverse reaction with foods. Food IgE sensitization was similar in both groups (17.5% versus 16.5%, respectively). 410 food challenge tests in 164 CSU patients and 38 in 38 control subjects were performed. 1.2% in CSU group and 0.7% in control group had a positive oral challenge test. Conclusion Despite the high frequency of self-report by patients, foods are uncommon triggers of CSU. Nevertheless, food challenge tests have to be offered early during medical evaluation to avoid unnecessary restrictions.

Accuracy of serum IgE concentrations and papule diameter in the diagnosis of cow's milk allergy

ObjectiveTo compare serum concentrations of specific IgE and mean papule diameters induced in the immediate skin reactivity test with cow's milk and its fractions with results of the oral challenge test, and to establish cutoff points capable of predicting clinical reactivity to cow's milk in patients treated at a referral service. MethodsOne hundred and twenty‐two children (median of 17 months) with a history of immediate reactions to cow's milk and presence of specific IgE for cow's milk and/or its fractions (positive skin and/or IgE serum tests) were submitted to open oral challenge test with cow's milk. ResultsThe oral challenge test was positive in 59.8% of the children, 49% of whom were males. Serum levels of specific IgE, as well as mean cow's milk papule diameters, were significantly higher in allergic patients (medians: 3.39kUA/L vs. 1.16kUA/L, 2.5mm vs. 0mm). The optimal cutoff points (Youden's index) of serum IgE specific for cow's milk and its fractions capable of predicting cow's milk reactivity (positive oral challenge test) were: 5.17kUA/L for cow’s milk, 0.95kUA/L for α‐lactalbumin, 0.82kUA/L for β‐lactoglobulin, and 0.72kUA/L for casein, whereas for papule diameters the cutoff points were 3.5mm for cow's milk and 6.5mm, 9.0mm, and 3.0mm for the α‐lactalbumin, β‐lactoglobulin, and casein fractions, respectively. ConclusionsThe cutoff points capable of predicting clinical reactivity to cow's milk were: 5.17kUA/L for serum‐specific IgE and 3.5mm for papule diameter measurement, values considered discriminatory for the diagnosis of cow's milk allergy.

Relationship maternal subcutaneous adipose tissue thickness and development of gestational diabetes mellitus.

ObjectiveWe investigated whether the ultrasonographic measurement of maternal subcutaneous adipose tissue (SAT) thickness in the second trimester played a role in predicting gestational diabetes.Materials and methodsThis was a prospective cross-sectional study in which 223 women were classified as healthy (n = 177) or as gestational diabetes (n = 46) on the basis of a negative or positive two-step oral Glucose Challenge Test (GCT), respectively. The depth of the abdominal SAT was evaluated by two-dimensional ultrasonography. Body mass index (BMI), waist circumference (WC), and waist/hip ratio were determined.ResultsThere was a positive strong significant correlation between a 50-g GCT level and BMI, WC, and SAT thickness (p < 0.001). Receiver-operating characteristic curve analysis showed SAT thickness above 16.75 mm predicted gestational diabetes mellitus (GDM) with a sensitivity of 71.7%, a specificity of 57.1%, a positive predictive value of 32.3%, and a negative predictive value of 87.6%. There was a good correlation between SAT, BMI, and WC.ConclusionIncreased SAT, BMI, and WC measurements may be helpful in predicting the risk of the development of GDM in pregnant women.

Accuracy of serum IgE concentrations and papule diameter in the diagnosis of cow's milk allergy

ObjectiveTo compare serum concentrations of specific IgE and mean papule diameters induced in the immediate skin reactivity test with cow's milk and its fractions with results of the oral challenge test, and to establish cutoff points capable of predicting clinical reactivity to cow's milk in patients treated at a referral service. MethodsOne hundred and twenty-two children (median of 17 months) with a history of immediate reactions to cow's milk and presence of specific IgE for cow's milk and/or its fractions (positive skin and/or IgE serum tests) were submitted to open oral challenge test with cow's milk. ResultsThe oral challenge test was positive in 59.8% of the children, 49% of whom were males. Serum levels of specific IgE, as well as mean cow's milk papule diameters, were significantly higher in allergic patients (medians: 3.39kUA/L vs. 1.16kUA/L, 2.5mm vs. 0mm). The optimal cutoff points (Youden's index) of serum IgE specific for cow's milk and its fractions capable of predicting cow's milk reactivity (positive oral challenge test) were: 5.17kUA/L for cow's milk, 0.95kUA/L for α-lactalbumin, 0.82kUA/L for β-lactoglobulin, and 0.72kUA/L for casein, whereas for papule diameters the cutoff points were 3.5mm for cow's milk and 6.5mm, 9.0mm, and 3.0mm for the α-lactalbumin, β-lactoglobulin, and casein fractions, respectively. ConclusionsThe cutoff points capable of predicting clinical reactivity to cow's milk were: 5.17kUA/L for serum-specific IgE and 3.5mm for papule diameter measurement, values considered discriminatory for the diagnosis of cow's milk allergy.

Proactive penicillin allergy testing in primary care patients labeled as allergic: outcomes and barriers

ABSTRACTObjectives: To promote penicillin allergy testing in an outpatient setting in patients labeled as penicillin allergic, to determine the number of those who are truly allergic, evaluate patient satisfaction with the testing, and educate both patients and clinicians about testing.Methods: Patients with a history of penicillin allergy listed in their EHR were screened and recruited by their primary care office and referred for penicillin allergy testing. The results of allergy testing and patient satisfaction after testing were the main outcomes. We also surveyed the primary care physicians about perceived barriers to recruitment.Results: A total of 82 patients were recruited, although only 37 actually underwent testing. None of these 37 had a positive skin test, and none of 36 had a positive oral challenge (1 refused it). Following testing, 2 patients (5%) had subjective reactions within 24 h. Thirty-one patients (84%) responded to a post-testing follow-up questionnaire; 3 (10%) were subsequently treated with a beta-lactam, and all reported that testing provided important information to their medical history. Providers identified time constraints, either their or their patients lack of time, as the major barrier to recruitment.Conclusions: Penicillin allergy testing safely evaluates patients labeled as penicillin allergic. It is well tolerated, and embraced by the patients who undergo testing. In our study, none of the patients tested had an allergic reaction, but we identified multiple barriers to developing a protocol for testing patients from the primary care setting.

Amino acid formula as a new strategy for diagnosing cow’s milk allergy in infants: is it cost-effective?

Aims: To estimate the cost-effectiveness of a new strategy that uses an amino acid formula in the elimination diet of infants with suspected cow’s milk allergy (CMA).Materials and methods: This pharmacoeconomic study was developed from the perspective of the Brazilian Public Healthcare System. The new strategy proposes using an amino acid formula in the diagnostic elimination diet of infants (≤24 months) with suspected CMA. The rationale is that infants who do not respond to the amino acid formula do not suffer from CMA. Patients with a positive oral challenge test receive a therapeutic elimination diet based on Brazilian Food Allergy Guidelines. This approach was compared to the current recommendations of the Brazilian Food Allergy Guidelines. A decision model was constructed using TreeAge Pro 2012 software. Model inputs were based on a literature review and the opinions of a panel of experts. A univariate sensitivity analysis of incremental cost-effectiveness ratios was performed.Results: The mean cost per patient of the new amino acid formula strategy was R$3,341.57, while the cost of the current Brazilian guidelines strategy was R$3,641.08. The mean number of symptom-free days per patient, which was used as an indicator of effectiveness, was 900.6 and 875.7 days, respectively. The new strategy is, therefore, dominant. In the sensitivity analysis, the dominance was maintained with parameter variation.Limitations: In the absence of information in the literature, some premises were defined by a panel of specialists.Conclusions: The new strategy, which uses an amino acid formula in the elimination diagnostic diet followed by an oral food challenge, is a dominant pharmacoeconomic approach that has a lower cost and results in an increased number of symptom-free days.

A randomized, double-blinded crossover trial testing the benefit of two hydrolysed poultry-based commercial diets for dogs with spontaneous pruritic chicken allergy.

Hydrolysed protein diets are used to diagnose and treat dogs with cutaneous adverse food reactions (CAFR). Little is known about what proportion of dogs hypersensitive to the native protein would react to its hydrolysed form. To determine the clinical allergenicity of hydrolysed poultry feather (RCU) and chicken liver diets (HZD) in dogs with chicken induced CAFR. In this randomized, double-blinded, crossover trial, ten dogs with chicken induced CAFR were selected after a positive oral challenge to chicken meat and a negative one to corn. Test diets were fed for 14days separated by a 14 day wash-out period. Owners rated pruritus daily with a Visual Analog Scale (PVAS). The challenge was ended if a flare in pruritus occurred (i.e. PVAS ≥5/10). The median PVAS scores before feeding RCU and HZD were 0.9 and 1.7, respectively (Wilcoxon signed rank test, P=0.46). Pruritus scores increased significantly after feeding HZD (Friedman's test, P<0.001) but not after feeding RCU (P=0.895). None of the dogs fed RCU, but four dogs fed HZD (40%), were withdrawn after a flare in pruritus developed (Fisher's test, P=0.04). The maximal PVAS score was significantly higher after HZD (median: 4.7) compared to RCU (2.5) (Wilcoxon signed rank test, P=0.01). One dog in each group was withdrawn due to diarrhoea. The hydrolysed poultry feather diet did not induce pruritus flares in dogs allergic to chicken in contrast to the hydrolysed chicken liver diet that led to pruritus flares in 40% of these dogs.

Evaluating Risk Factors for a Positive Oral Challenge Despite Negative Penicillin Skin Testing

Evaluating Risk Factors for a Positive Oral Challenge Despite Negative Penicillin Skin Testing

Food allergy in children with refractory gastroesophageal reflux disease.

Gastroesophageal reflux disease (GERD) and food allergy are frequent disorders of childhood. The purpose of this study was to determine the frequency of food allergy in children with refractory GERD. A total of 151 children resistant to pharmacologic GERD treatment underwent skin prick test, specific immunoglobulin E, eosinophil count, atopy patch test (APT), and oral food challenge, and were then divided into three groups according to the results of oral milk challenge and allergy work-up: group A1, positive oral milk challenge and positive IgE-mediated allergy test; group A2, positive milk challenge and negative IgE-mediated allergy test; and group B, negative oral milk challenge and negative allergy tests. There were 35, 30 and 86 patients in group A1, group A2 and group B, respectively. A total of 28 of 35 patients in group A1 had cow's milk allergy and the other seven patients had egg allergy. APT positivity was more common in group A2. Endoscopic esophagitis was observed in six group A1 patients and in four group A2 patients. Bloody stools, atopic dermatitis and recurrent wheezing episodes were significantly more common in group A1 than in group A2 and group B (P < 0.001, for both). Cow's milk allergy was observed frequently in children resistant to pharmacologic GERD treatment. Combined skin prick and specific IgE tests, APT and oral food challenge is essential for avoidance of unnecessary elimination diet.

Maternal hyperglycemia and the 100-g oral glucose tolerance test

ObjectivesTo compare the characteristics of pregnant women with hyperglycemia according to the severity of glucose intolerance using the 100-g oral glucose tolerance test (OGTT) and to demonstrate the need to manage the condition of women with mild hyperglycemia. Materials and methodsIn this retrospective cohort study, a total of 258 women at high risk of gestational diabetes (GDM) based on a positive 50-g oral glucose challenge test (OGCT) were classified into 0+, 1+, 2+, 3+, and 4+ groups according to the number of abnormal plasma glucose values on the 100-g OGTT. The clinical characteristics of the groups were compared. ResultsThe rates of advanced maternal age (≥ 35 years), multiparity, prior history of GDM, preterm birth, cesarean delivery, and elevated body mass index were all positively correlated with the number of abnormal plasma glucose values on the OGTT (p < 0.05 for all variables). After adjusting for confounding factors, the fasting plasma glucose levels predicted birth weight in 44.4%, 48.4%, and 58.6% of the women in the positive 50-g OGCT group, the 0+ group, and the 1+ group, respectively. Weight gain during pregnancy predicted birth weight in 42%, 44.6%, and 37.6% of the women in the positive 50-g OGCT group, the 0+ group, and the 2+ group, respectively (p < 0.001 in each case). ConclusionsThese data demonstrate that the detection and management of mild hyperglycemia below the current diagnostic criteria of GDM as well as GDM diagnosed using the 100-g OGTT are necessary for improving pregnancy outcomes.