Treatment Difficulties in Wheat Oral Immunotherapy and the Predictive Value of Wheat-Specific IgE.

BACKGROUND: Factors associated with wheat oral immunotherapy (OIT) difficulties in patients with IgE-mediated wheat allergy have not been well studied. OBJECTIVE: We aimed to assess factors associated with difficulties in wheat OIT. METHODS: We retrospectively collected data from children under 18 years of age with history of IgE-mediated wheat allergy who underwent wheat OIT. The initial specific IgE (sIgE) of wheat and omega-5-gliadin, wheat skin prick test (SPT) sizes, eliciting doses, and adverse reactions during the OIT were evaluated. RESULTS: A total of 81 children were enrolled, with a mean age of 7.0 ± 2.7 years at the initiation of wheat OIT. The median follow-up duration was 2 years (IQR 1.2 -3.0 years). Difficulties in wheat OIT included patients who experienced frequent reactions (at least grade 2 or exercise-induced reactions) or deviated from the up-dosing protocol, which we defined as 'Complicated cases.' Twenty-six patients (32.1%) were complicated cases. Initial wheat-sIgEs were significantly higher in complicated cases than in noncomplicated cases (median of 192.3 kUA/L (IQR 30.4-590.0) vs 6.9 kUA/L (IQR 1.9-100.0) (p = 0.001)). Initial omega-5-gliadin-sIgEs in the complicated group were also significantly higher, with a median of 15.0 kUA/L (IQR 6.3-69.8) vs 1.6 kUA/L (IQR 0.2-11.4) (p < 0.001). The risk factors for complicated cases include higher omega-5-gliadin-sIgEs and anaphylaxis during the oral food challenge test (aOR 1.035 and 5.684, respectively). CONCLUSION: The initial wheat and omega-5-gliadin-sIgEs were significant risk factors for complicated OIT patients and could be used to monitor these patients carefully during the OIT period.

Factor associated with food allergy among preschool children with atopic dermatitis, and resolution of atopic dermatitis.

BACKGROUND: Food allergy (FA) has been reported in one-third of children with moderate-to-severe atopic dermatitis (AD). OBJECTIVE: To identify factor associated with food allergy among preschool children with AD, and to compare AD resolution between preschool children with and without FA. METHODS: A cross-sectional study using database registry and questionnaire interview was conducted at Siriraj Hospital(Bangkok, Thailand) during 2022, and physician-diagnosed AD children aged ≤ 6 years were enrolled. RESULTS: A total of 110 children (60.9% male, median age: 2.3 years) were included. Of those, 53 and 57 children had AD with and without FA, respectively. Very early-onset AD (≤ 3 months) and moderate-to-severe AD at onset were reported in 43.9% and 26.3% of AD without FA, and in 35.8% and 45.3% of AD with FA, respectively. The most commonly reported FAs were hen's egg, cow's milk, and wheat. Moderate-to-severe AD at onset was found significant associated with FA (aOR: 2.50; p = 0.037). Thirty-one (28.2%) patients experienced completed resolution of AD by 5 years of age. Of those, 19 had AD without FA, and 12 had AD with FA (p = 0.213). The median age at AD resolution was 18 months and 22.5 months in the without and with FA groups, respectively. AD with FA showed a strong trend toward a significantly longer duration to achieving AD resolution after adjusting for onset and severity of AD (aHR: 0.46, p = 0.050). CONCLUSION: Preschool AD children with FA were found to have significantly greater AD severity at AD onset and a longer duration to AD resolution compared to AD children without FA.

Identifying the stability of a new wheat gliadin extract by protein analysis, skin tests and cell degranulation assay.

BACKGROUND: The commercial wheat extract for skin prick test (SPT) provides less sensitivity to predict wheat allergy, compared to in-house gliadin extracts. SPT is a preferred method to study extract stability as it is the aim of developing extract. The role of cell degranulation assay, a functional assay with the same mechanism as SPT, is not widely used to determine extract stability. OBJECTIVE: To study the stability of in-house gliadin extracts stored at different periods, by using protein analysis, SPT and degranulation assay of humanized rat basophilic-leukemia (RBL-SX38) cells. METHODS: Patients with a history of wheat allergy and positive SPT to wheat, were recruited. The gliadin extracts stored for 1, 6, 9, and 12 months at 2-8°C were used in SDS-PAGE, SPT and cell degranulation assay. The cell degranulation was determined by ß-hexosaminidase release. AR patients. RESULTS: Forty children were recruited. The gliadin extract stored for 9 and 12 months provided lighter protein bands than 1 and 6 months. However, the wheal diameters from SPT using extracts stored at different periods, were not significantly different (p = 0.09). There were also no significant differences of the ß-hexosaminidase released using 0.1 and 1 µg/mL of gliadin extracts stored at different periods (p > 0.05). The 10 µg/mL of gliadin extracts stored at longer periods, significantly stimulated higher ß-hexosaminidase release (p = 0.01). The extracts were sterile at all storage times. CONCLUSIONS: To determine the stability of in-house gliadin extracts, SPT or cell degranulation assay provided additional information to SDS-PAGE. The extracts were stable for up to 12 months.

Practical recommendations for home-nebulized corticosteroid use in children aged ≤ 5 years with asthma: A review and advisory group consensus.

BACKGROUND: Despite nebulized budesonide being identified by the Global Initiative for Asthma report as a viable alternative to inhaled corticosteroids (ICS) delivered by pressurized metered-dose inhalers (pMDIs) with spacers, practical guidance on nebulized corticosteroid use in the pediatric population remains scarce. OBJECTIVE: To review the current literature and provide practical recommendations for nebulized budesonide use in children aged ≤ 5 years with a diagnosis of asthma. METHODS: A group of 15 expert pediatricians in the respiratory and allergy fields in Thailand developed Delphi consensus recommendations on nebulized budesonide use based on their clinical expertise and a review of the published literature. Studies that evaluated the efficacy (effectiveness) and/or safety of nebulized budesonide in children aged ≤ 5 years with asthma were assessed. AR patients. RESULTS: Overall, 24 clinical studies published between 1993 and 2020 met the inclusion criteria for review. Overall, results demonstrated that nebulized budesonide significantly improved symptom control and reduced exacerbations, asthma-related hospitalizations, and the requirement for oral corticosteroids compared with placebo or active controls. Nebulized budesonide was well tolerated, with no severe or drug-related adverse events reported. Following a review of the published evidence and group consensus, a treatment algorithm as per the Thai Pediatric Asthma 2020 Guidelines was proposed, based on the availability of medications in Thailand, to include nebulized budesonide as the initial treatment option alongside ICS delivered by pMDIs with spacers in children aged ≤ 5 years. CONCLUSIONS: ThNebulized budesonide is an effective and well-tolerated treatment option in children aged ≤ 5 years with asthma.

The natural history of childhood-onset nonallergic rhinitis; a long-term follow-up study.

BACKGROUND: Non-allergic rhinitis (NAR) is characterized by symptoms of nasal inflammation without allergic sensitization. The long-term outcome of NAR in children is poorly defined. OBJECTIVE: To determine the natural history of childhood-onset NAR and the development of allergic rhinitis (AR) in these children. METHODS: NAR patients who were followed for more than 10 years were evaluated at 3-5 years (E2) and 9-12 years (E3) after the first evaluation (E1). Nasal symptoms, disease severity, comorbidities, medication used, and aeroallergen sensitization were assessed. RESULTS: Eighty-two NAR patients (58.5% male) completed all 3 evaluations. The age at onset was 2.0 (range 2.0-4.0) years. The follow-up period was 13.6 (range 12.3-14.3) years. At E2, 37.8% of patients developed AR. At E3, the patients were classified into four groups based on results of skin prick tests in E2 and E3 (group I: NAR→NAR→NAR, 39.0%, group II: NAR→NAR→AR, 23.2%, group III: NAR→AR→NAR, 12.2% and group IV: NAR→AR→AR, 25.6%). The most common aeroallergen sensitization was house dust mite. The family history of atopy, asthma and allergic rhinitis were higher in group III and IV than other groups (p < 0.05). The atopic dermatitis, obstructive sleep apnea and adenotonsillar hypertrophy at E1 and E2 were predominantly found in group IV (p < 0.05). At E2, group III and IV patients had higher proportion of exposure to house dust, animal dander and smoking compared to other groups (p < 0.05). The overall remission rate was 14.6%. CONCLUSIONS: Children with NAR should be reevaluated periodically to determine aeroallergen sensitization for the appropriate diagnosis and management.

Food-Dependent Exercise-Induced Wheals/Angioedema, Anaphylaxis, or Both: A Systematic Review of Phenotypes.

BACKGROUND: Food-dependent exercise-induced allergic reactions can manifest with wheals, angioedema, and anaphylaxis, alone or in combination. OBJECTIVE: To systematically review the clinical manifestation, culprit foods and exercise, augmenting factors, comorbidities, and treatment options of each phenotype. METHODS: Using predefined search terms, we assessed and analyzed the relevant literature until June 2021. Preferred Reporting Items for Systematic Reviews and Meta-Analysis recommendations were applied to this systematic review. RESULTS: A total of 231 studies with 722 patients were included. The most common phenotype was anaphylaxis with wheals, angioedema, or both, reported in 80% of patients. This was associated with a higher number of anaphylactic episodes, augmenting factors, and use of on-demand antihistamine compared with the least common phenotype, anaphylaxis without wheals or angioedema, reported in 4% of patients. Anaphylaxis with wheals/angioedema was also associated with distinct characteristics compared with stand-alone wheals, angioedema, or both, in 17% of patients. Patients with anaphylaxis were older at the time of disease onset, less often had a history of atopy, showed more positive results in response to food and exercise provocation tests, had a more restricted spectrum of culprit foods, and more often used on-demand epinephrine. CONCLUSIONS: The three phenotypes of allergic reactions to food and exercise differ in clinical characteristics, triggers, and response to treatment. Knowledge of these differences may help with patient education and counseling as well as disease management.

Children with wheat anaphylaxis and with low wheat specific IgE have a different IgE immunoblot pattern than those with high wheat specific IgE.

BACKGROUND: Children with wheat anaphylaxis can present with a wide range of wheat-specific IgE (sIgE). OBJECTIVE: To identify differences in clinical features and predominant wheat allergens sensitized by these patients. METHODS: Children with history of wheat anaphylaxis were recruited. Skin prick test (SPT) to wheat, sIgE to wheat, omega-5 gliadin (ω5G), lipid transfer protein (LTP) were investigated. Profiles of IgE-bound wheat allergens were studied to identify predominant wheat allergens. RESULTS: Twenty-nine children (17 males) aged 1-18 years were enrolled. Sixteen patients (55.2%) had wheat-sIgE > 100 kUA/L (WAhi) and 13 patients (44.8%) had wheat-sIgE < 34 kUA/L (WAlo). The median of peak wheat-sIgE in WAhi and WAlo were 340.5 kUA/L (IQR 184.3, 564.5) and 12.2 kUA/L (IQR 1.4, 41.3), respectively. Oral food challenge test (OFC) was carried out in 12 of 13 patients in the WAlo group, all of which had positive results. Eight of these 12 patients developed anaphylaxis during OFC despite having wheat-sIgE less than 10 kUA/L. There were no differences in clinical characteristics and atopic history between WAhi vs. WAlo. Medium to low molecular weight gliadin (< 40 kDa) and glutenin (< 60 kDa) were commonly recognized by patients with WAhi. IgE immunoblot pattern among the WAlo group was more widely dispersed than those with WAhi. CONCLUSIONS: Wheat anaphylaxis can occur in patients with low wheat-sIgE. Predominant wheat allergens recognized by patients with WAlo were different than those with WAhi. Such difference could be responsible for anaphylaxis at even low levels of wheat-sIgE.

A potential role of gliadin extract skin prick test in IgE-mediated wheat allergy.

BACKGROUND: Wheat extracts containing both water/salt and alcohol soluble proteins may increase extract's accuracy for diagnosing IgE-mediated wheat allergy. OBJECTIVE: This study aimed to determine the performance of new invented in-house prepared wheat extracts for skin prick test (SPT). METHODS: Children aged 1-18 years with history of immediate wheat allergy were recruited. Four in-house prepared wheat extracts (wheat-Coca-10%EtOH, and 3 new invented extracts, wheat-salt, gliadin, and glutenin) and a commercial wheat extract were used for SPT. Serum specific IgE (sIgE) to wheat and omega-5 (ω-5) gliadin were also determined. Oral food challenge (OFC) with wheat flours was performed in all patients except those with history of wheat-induced anaphylaxis or with recent symptoms within the past 6 months. RESULTS: Thirty-one children were recruited. Of those, 14 were excluded from OFC (12 with history of anaphylaxis and 2 with recent symptom). OFC was positive in 8 of 17 children. Of the 5 extracts and sIgE to wheat and ω-5 gliadin, gliadin extract provided the best SPT performance with 84.2% sensitivity, 88.9% specificity, 94.1% positive predictive value (PPV), 72.7% negative predictive value (NPV), 7.59 positive likelihood ratio (LR), 0.18 negative LR, and 85.7% accuracy. CONCLUSIONS: Compared to other in-house and commercial wheat extracts and sIgE to wheat and ω-5 gliadin, SPT with an in-house gliadin extract yielded the highest performance for the diagnosis IgE-mediated wheat allergy.

Validation and Reliability of the Thai version of the Food Allergy Quality of Life Questionnaire-Parent Form (FAQLQ-PF).

BACKGROUND: Food allergy has an impact on the quality of life of both patients and caregivers. It is, therefore, important to have a native language survey to evaluate health-related quality of life (HRQL) among food allergic children. OBJECTIVE: To translate the Food Allergy Quality of Life Questionnaire-Parent Form (FAQLQ-PF) to Thai language, and to validate this tool in Thai parents with food allergic children. METHODS: The FAQLQ-PF was translated into Thai language according to WHO guideline. The FAQLQ-PF Thai version was then administered to the parents of food allergic Thai children aged 0-12 years. The FAQLQ-PF Thai version was then readministered to those same parents 10-14 days after they first completed this assessment tool. Internal consistency by Cronbach's α and test-retest reliability by intraclass correlation coefficient (ICC) were assessed. The discriminant validity of the questionnaire was also evaluated. RESULTS: Ninety parents of participants answered the FAQLQ-PF Thai version. Of those, 9 parents (10%) incompletely answered the first questionnaire. The FAQLQ-PF Thai version showed good internal consistency (Cronbach's α ≥ 0.799), but the test-retest reliability was only fair (ICC > 0.6). Factors that adversely affected the quality of life of Thai children with food allergy included age, presence of anaphylaxis, frequency of reactions, and the number of implicated foods. Patients with wheat allergy were negatively impacted in all domains of quality of life, whereas those with shellfish allergy had only emotional impact. CONCLUSIONS: The FAQLQ-PF Thai version is a reliable and valid tool for assessing HRQL in Thai children with food allergy.

Is mold sensitization associated with severe asthma exacerbation in children?

BACKGROUND: Mold sensitization has been reported as a factor associated with severe asthma exacerbation (SAE). OBJECTIVE: To identify the factors associated with SAE in asthmatic children, particularly mold sensitization. METHODS: The asthmatic children recruited into this case-control study were classified into an SAE and an outpatient (OPD) group, based on their histories of asthma exacerbation with hospitalization in the preceding year. A skin prick test to common aeroallergens was performed. Possible SAE risk factors were analyzed. RESULTS: A total of 102 patients were enrolled. The 51 patients in the SAE group were significantly younger than the 51 in the OPD group (mean ages of 6.8 ± 3.3 vs 8.7 ±3.2 years, p = 0.005). Higher proportions of patients with partly controlled or uncontrolled asthma were found in the SAE group (41.2% vs 17.6%, p = 0.009). The incidences of a paternal history of atopy, an emergency department visit, and a history of systemic corticosteroid administration in the preceding year were significantly higher for the SAE group (35.3% vs 15.7%, p = 0.023; 100% vs 43.5%, p < 0.001; and 100% vs 31.4%, p < 0.001; respectively). The multivariate logistic regression analysis showed that risk factors for SAE were Alternaria sensitization (adjusted odds ratio [AOR] 3.00; 95% CI 1.09-8.3; p = 0.033), patients who were younger than 6 years (AOR 3.28; 95% CI 1.17-9.18; p = 0.024), and a paternal history of atopy (AOR 2.94; 95% CI 1.05-8.25; p = 0.040). CONCLUSIONS: Alternaria sensitization, an age younger than 6 years, and a paternal history of atopy were associated with SAE in asthmatic children.

Systemic absorption of epinephrine compared between the intranasal and intramuscular routes of administration in healthy adults.

BACKGROUND: Epinephrine 5 mg administered via the intranasal (IN) route was shown to be bioequivalent to epinephrine 0.3 mg administered via the intramuscular (IM) route in our preliminary study. OBJECTIVE: To investigate the pharmacokinetics and pharmacodynamics of IN and IM epinephrine absorption in a larger group of healthy adults (n = 12). METHODS: Each subject was administered IN saline, IN epinephrine (5 mg), and IM epinephrine (0.3 mg) on 3 separate days. Plasma epinephrine levels were determined using liquid chromatography-tandem mass spectrometry. RESULTS: IN epinephrine administration showed significant systemic absorption compared to IN saline control with the areas under the curve (AUC0-180 min) of 4.4 (4.9) ± 4.0 and 0.2 (0.5) ± 0.3 ng.min/mL, respectively; the values are mean (median) ± standard deviation. IN epinephrine absorption was about 0.5-fold that of IM epinephrine (AUC0-180 min 10.0 (9.2) ± 8.6 ng.min/mL), but the difference was not statistically significant (p = 0.16). The mean peak epinephrine concentration and the time to reach it were also not significantly different between the IN and IM routes. The corresponding values were 120 pg/mL and 41 min for IN, and 209 pg/mL and 41 min for IM, respectively. CONCLUSIONS: The systemic absorption of IN epinephrine 5 mg was significantly different from the control IN saline and about 0.5-fold that of IM epinephrine 0.3 mg. Although epinephrine administration via the less invasive IN route is safe and feasible, further investigations are necessary to achieve an adequate and consistent systemic absorption comparable to that of the conventional IM injection.

Food-Dependent Exercise-Induced Wheals, Angioedema, and Anaphylaxis: A Systematic Review.

BACKGROUND: Food-dependent exercise-induced wheals, angioedema, and anaphylaxis remain insufficiently characterized. OBJECTIVE: We systematically reviewed the literature on clinical manifestations, laboratory investigations, culprit foods, triggering exercise, comorbidities, and treatment outcomes. METHODS: Using predefined search terms and Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) recommendations, we searched 3 electronic databases to identify relevant literature published before July 2021. RESULTS: Of 722 patients (median age 25 years; 55.4% male) from 231 studies (43 cohort studies, 15 cases series, and 173 case reports), 79.6% and 3.7% had anaphylaxis with and without wheals and/or angioedema, respectively. The remaining 16.6% had wheals and/or angioedema without anaphylaxis. The duration from eating to exercising and from exercising to symptom onset ranged from 5 minutes to 6 hours (median 1 hour) and from 5 minutes to 5 hours (median 30 minutes), respectively, and virtually all patients exercised within 4 hours after eating and developed symptoms within 1 hour after exercising. Wheat was the most common culprit food. Running was the most common trigger exercise. Most patients were atopic, and 1 in 3 had a history of urticaria. Aspirin and wheat-based products were the most frequent augmenting factors. On-demand antihistamines, corticosteroids, and epinephrine were commonly used and reported to be effective. Patients who stopped eating culprit foods before exercise no longer developed food-dependent exercise-induced allergic reactions. CONCLUSIONS: Food-dependent exercise-induced allergic reactions are heterogeneous in their clinical manifestations, triggers, and response to treatment. Patients benefit from avoidance of culprit foods before exercise, which highlights the need for allergological diagnostic workup and guidance.

Comprehending the allergen repertoire of shrimp for precision molecular diagnosis of shrimp allergy.

BACKGROUND: Clinical management of shrimp allergy is hampered by the lack of accurate tests. Molecular diagnosis has been shown to more accurately reflect the clinical reactivity but the full spectrum of shrimp allergens and their clinical relevance are yet to be established. We therefore sought to comprehend the allergen repertoire of shrimp, investigate and compare the sensitization pattern and diagnostic value of the allergens in allergic subjects of two distinct populations. METHODS: Sera were collected from 85 subjects with challenge-proven or doctor-diagnosed shrimp allergy in Hong Kong and Thailand. The IgE-binding proteins of Penaeus monodon were probed by Western blotting and identified by mass spectrometry. Recombinant shrimp allergens were synthesized and analyzed for IgE sensitization by ELISA. RESULTS: Ten IgE-binding proteins were identified, and a comprehensive panel of 11 recombinant shrimp allergens was generated. The major shrimp allergens among Hong Kong subjects were troponin C (Pen m 6) and glycogen phosphorylase (Pen m 14, 47.1%), tropomyosin (Pen m 1, 41.2%) and sarcoplasmic-calcium binding protein (Pen m 4, 35.3%), while those among Thai subjects were Pen m 1 (68.8%), Pen m 6 (50.0%) and fatty acid-binding protein (Pen m 13, 37.5%). Component-based tests yielded significantly higher area under curve values (0.77-0.96) than shrimp extract-IgE test (0.70-0.75). Yet the best component test differed between populations; Pen m 1-IgE test added diagnostic value only in the Thai cohort, whereas sensitizations to other components were better predictors of shrimp allergy in Hong Kong patients. CONCLUSION: Pen m 14 was identified as a novel shrimp allergen predictive of challenge outcome. Molecular diagnosis better predicts shrimp allergy than conventional tests, but the relevant component is population dependent.

Defining Biomarkers to Predict Natural Resolution in Shrimp Allergy.

PURPOSE: Tolerance to shrimp has been reported in some patients with a history of shrimp allergy. The predictors of the natural resolution of shrimp allergy have not been widely explored. This study aimed to investigate the role of specific IgE (sIgE) and specific IgG4 (sIgG4) to shrimp extracts and the cross-reactive shrimp allergens tropomyosin (TM), arginine kinase (AK) and myosin light-chain (MLC), as markers of persistent or resolved shrimp allergy (PSA or RSA). METHODS: Seventeen patients with a 10-year history of allergy to Penaeus monodon (Pm) and/or Macrobachium rosenbergii (Mr) were recruited. Oral shrimp challenges identified 10 patients with PSA and 7 patients with RSA. Sera from these patients were evaluated for sIgE and sIgG4 to Mr and Pm extracts as well as to TM, AK and MLC. RESULTS: The levels of sIgE to Mr and Pm extracts were lower in the RSA than in the PSA groups (P = 0.05 and P = 0.008, respectively), but sIgG4 or sIgG4:sIgE ratio did not show statistical significance. The sIgE to AK and MLC, but not TM, were lower in the RSA group than in the PSA group (P = 0.009 and P = 0.0008, respectively). There was no difference in sIgG4 to TM, AK and MLC between both groups. The ratio of sIgG4:sIgE to MLC, but not TM or AK, was higher in the RSA than in the PSA group (P = 0.02). A higher diversity of sIgE to shrimp components was found in the PSA group than in the RSA group (P = 0.006). CONCLUSIONS: Specific bioassays can be used to identify patients with RSA. Oral shrimp challenges in these patients may provide a higher rate of passing the challenges and finally reintroducing shrimp in their diet.

Clinical characteristics and outcomes of ocular allergy in Thai children.

BACKGROUND: Allergic conjunctivitis (AC) is the most common ocular condition in allergic children. In tropical countries, the study about the clinical features and outcome of treatment is very limited. OBJECTIVE: To review clinical characteristics and outcomes of treatment in children with ocular allergy. METHODS: Children with history of AC were classified to seasonal allergic conjunctivitis (SAC), perennial allergic conjunctivitis (PAC), vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC). The clinical history and outcome of treatment were recorded. RESULTS: One hundred and sixty-four children were recruited. PAC was the most common type (61.6%), followed by SAC (21.3%), VKC (12.2%), and AKC (4.9%). Male preponderance was found in all groups. Mean age of onset was 6.8 ± 2.8 years. Allergic rhinitis was the most common co-morbidity (97.6%). The common sensitized allergen is house-dust mites (86.1%). Standard treatments in all groups were natural tear and topical olopatadine. Add-on medications were usually needed in severe types of AC (VKC, AKC). History of topical corticosteroid use was 68.8% and 12.5% in VKC and AKC, respectively. All of them can discontinue topical corticosteroid when topical tacrolimus was applied. The overall remission was found 35% in VKC group and 63% in AKC group. The median duration of treatment was 20.5 months in VKC group and 11 months in AKC group. CONCLUSIONS: most Thai children with AC sensitized to house-dust mites. In severe forms of AC, most patients needed addon medication. The use of topical calcineurin inhibitor as an add-on therapy can decrease the use of topical corticosteroid.

Food sensitization and food allergy in allergic Thai patients from a tertiary care center in Thailand.

BACKGROUND: A skin prick test (SPT) and food challenge test (OFC) are useful in identification of food sensitization and food allergy. OBJECTIVE: To evaluate food allergen sensitization by SPT and food allergy by OFC in allergic Thai patients. METHODS: SPTs for common food allergens were performed on allergic patients at Siriraj Hospital, Bangkok, Thailand, from 2011 to 2015. An OFC was performed in positive food SPT patients with informed consent. RESULTS: SPTs to food were positive in 539 (20%) out of 2,678 allergic patients (73.8% were < 10 years old). Crab was the most common sensitized food in each year of the study period. In patients aged < 1 year, the most common sensitized foods were egg white (23.8%) and wheat (22.2%), while shrimp was for patients aged > 10 years (25%). A positive OFC was found in 29 (26.1%) out of the 111 OFCs performed (9.1% in patients with asthma, 28.6% in allergic rhinitis and 26.3% in food allergy). Positive OFCs were found for 60% of the crab, 35.7% of the egg yolk, and 31% of the cow's milk OFCs. Compared to OFC, SPT showed high specificity (71%-100%) but low sensitivity (0%-40%). The percentage of sensitization to egg white, egg yolk, wheat, soy, and peanut significantly increased (p < 0.05) from 2011 to 2015. CONCLUSION: The sensitization to egg white, egg yolk, wheat, soy, and peanut significantly increased and crab was the most common sensitized food. Food allergy in patients with allergic rhinitis was as common as in patients diagnosed food allergy.

Effect of gene polymorphisms in ADAM33, TGFß1, VEGFA, and PLAUR on asthma in Thai population.

BACKGROUND: Most of the asthma susceptibility genes have demonstrated moderate effect. Gene-gene interaction may play a role in asthma. OBJECTIVE: To investigate the genetic and gene-gene interaction effects of single nucleotide polymorphisms (SNPs) in the ADAM33, TGFß1, VEGFA, and PLAUR genes on asthma in Thai population. METHODS: Two hundred and fifty control and 250 asthmatic Thai subjects were recruited. Asthma was diagnosed based on symptoms and spirometry assessments using criteria outlined by the American Thoracic Society. Degrees of asthma severity were determined according to guidelines provided by the Global Initiative for Asthma. Asthmatic subjects were subcategorized into the low-severity (n = 106) and high-severity (n = 144) groups. Eleven SNPs in four genes were genotyped, including ADAM33 SNPs (rs528557/S2, rs598418, rs44707/ST+4), TGFß1 SNPs (rs2241715, rs11466345), VEGFA SNPs (rs833069, rs3025010), and PLAUR SNPs (rs344781, rs344787, rs2239374, rs2239372). Association analyses between SNPs and asthma, and tests for gene-gene interaction were performed. RESULTS: The ADAM33 rs528557/S2 SNP was found to be associated with asthma according to the additive and dominant models. Comparison between the low-severity group and controls showed the VEGFA rs833069 SNP to be significantly associated with the low-severity group. No gene-gene interactions were observed in this study. CONCLUSIONS: The ADAM33 rs528557/S2 and the VEGFA rs833069 SNPs were associated with Thai asthmatics, as well as with other populations worldwide. Further studies are warranted to investigate the use these SNPs as biomarkers for establishing early diagnosis or for predicting future risk of asthma.

Characterization of children with IgE-mediated wheat allergy and risk factors that predict wheat anaphylaxis.

BACKGROUND: The number of children presenting with IgE-mediated wheat reactions to academic medical centers in Thailand continues to increase. OBJECTIVE: Improved knowledge about the clinical characteristic of wheat allergy is urgently needed to better understand the risk factors and to improve proper treatment in this patient population. METHODS: A cross-sectional study using questionnaire review of children who presented with IgE-mediated wheat allergy during 2001 to 2015 was performed. Patients were divided into the wheat anaphylaxis (WA) or the only skin symptoms (SO) group. RESULTS: One hundred children were enrolled. Fifty-one and 49 patients were allocated to the WA and SO group, respectively. The median age was 40.5 months (range: 6-200), and the median age of onset was 7 months (range: 3-96). The vast majrity (90%) developed their first reaction after their first ingestion of wheat. Atopic dermatitis (AD) was found to be the only significant difference between groups and found more commonly in SO than in WA (59.2% vs. 35.3%, p = 0.02). Median mean wheal diameter (MWD) of skin prick test (SPT) and median sIgE level to wheat were higher in WA than in SO (8 vs. 3 mm, p < 0.001; and, 33.3 vs. 3.6 kUA/l, p < 0.001). CONCLUSIONS: Children with wheat allergy presented very early in life. AD was found in approximately half of the patients, and more commonly in SO. Median MWD of SPT and sIgE level to wheat were significantly higher in WA. These data will aid in further planning for a larger survey and intervention study in wheat allergy.

Prevalence of rat and mouse sensitization in Asian patients with respiratory allergy.

BACKGROUND: Skin prick test (SPT) is useful in identifying rat and mouse sensitization. OBJECTIVE: To determine the prevalence of rat and mouse sensitization by using local and commercial allergen extracts. METHODS: Patients with allergic rhinitis or asthma were recruited. SPT of local and commercial rat and mouse allergen extracts were performed. The level of rat and mouse specific IgE (sIgE) was quantified in all patients with positive SPT and randomized patients with negative SPT. RESULTS: Two hundred and thirty patients, 108 male (47%) and median age 14 years (3.2-63.5 years), were enrolled. Rat sensitization by SPT was 11.7% and mouse sensitization was 17.8%. SPT result to local rat and commercial rat allergen extracts were moderately correlated (rs = 0.51, p < 0.001), while SPT result to local mouse and commercial mouse allergen extracts showed low correlation (rs = 0.38, p < 0.001). The concordance of SPT results between local rat and commercial rat allergen extracts was 90.4%. Concordance between the local mouse and commercial mouse allergen extracts was 85.2%. When compared with rat and mouse sIgE, the concordance of local rat, commercial rat and commercial mouse allergen extract were > 80% while that of local mouse was 54.4%. No adverse effect was observed in SPT with any allergen or extract. CONCLUSIONS: The prevalence of rat and mouse sensitization was low compared to the study in USA. SPT with local rat and mouse allergen extract was safe and showed good concordance with the SPT result of commercial allergen extracts and rat and mouse sIgE levels.