Self-reported questionnaire survey on the prevalence and symptoms of adverse food reactions in patients with chronic inhalant diseases in Tangshan city, China.

BACKGROUND: The prevalence of adverse food reactions in patients with chronic inhalant diseases has seldom been studied in China. This study is to investigate the prevalence of adverse food reactions and the symptoms caused in respiratory patients. METHODS: Respiratory patients in allergy clinics were asked to complete a questionnaire. Patients' information such as age, gender, family history of allergy, and adverse reactions to a list of 48 foods and the symptoms caused, was recorded. Multivariate analyses were performed to determine the prevalence of adverse food reactions and their associated symptoms. RESULTS: 459 subjects, with an average age of 32 years old, completed the questionnaire; 45.3% were male. Among the 459 subjects, 38.1% (175/459) had an adverse reaction to food: 13.6% had an adverse food reaction to crab, 12.4% had an adverse food reaction to shrimp; and 9.9% had an adverse reaction to shellfish. Peach and nectarine were also shown to be common causative foods with 6.8% of the study group showing an adverse reaction to peach and 5.2% to nectarine. Seafood mainly caused skin symptoms and fruits gave rise to more throat, oral, and gastrointestinal problems. CONCLUSION: The prevalence of adverse food reactions is high for patients with respiratory diseases. This indicates that adverse food reactions should be considered in the treatment and management of patients with chronic inhalant diseases.

High correlation of specific IgE sensitization between birch pollen, soy and apple allergens indicates pollen-food allergy syndrome among birch pollen allergic patients in northern China.

BACKGROUND: Birch pollen sensitization and associated pollen-food syndrome among Chinese allergic patients have not been investigated. METHODS: Sera from 203 allergic patients from the northern part of China and collected during February to July 2014 were investigated. Specific immunoglobulin E (IgE) against birch pollen extract Bet v and major birch pollen allergen Bet v 1 were measured using the ADVIA Centaur. The presence of major apple allergen Mal d 1 and soy bean allergen Gly m 4 specific IgE was measured by ImmunoCAP 100. RESULTS: Among the 203 sera, 34 sera (16.7%) had specific IgE to Bet v and of these, 28 sera (82.4%) contained Bet v 1-specific IgE. Among the 28 sera with Bet v 1-specific IgE, 27 sera (96.4%) contained Mal d 1-specific IgE and 22 sera (78.6%) contained Gly m 4-specific IgE. Of the 34 Bet v-positive sera, 6 sera (17.6%) contained no specific IgE for Bet v 1, Mal d 1, or Gly m 4. Almost all Bet v-positive sera were donated during the birch pollen season. CONCLUSIONS: The prevalence of birch allergy among patients visiting health care during pollen season can be as high as 16.7% in Tangshan City. The majority of Chinese birch allergic patients are IgE-sensitized to the major birch pollen allergen Bet v 1 as well as to the major apple allergen Mal d 1 and soy bean allergen Gly m 4. A relatively high number of patients (17.6%) are IgE-sensitized to birch pollen allergen(s) other than Bet v 1. The high prevalence of specific IgE to Mal d 1 and Gly m 4 among Bet v 1-sensitized patients indicates that pollen-food allergy syndrome could be of clinical relevance in China.

Prevalence of sensitization to weed pollens of Humulus scandens, Artemisia vulgaris, and Ambrosia artemisiifolia in northern China.

OBJECTIVE: Weed pollens are common sources of allergens worldwide. The prevalence of weed pollen sensitization is not yet fully known in China. The purpose of this study was to investigate the prevalence of sensitization to weed allergens from Artemisia, Ambrosia, and Humulus in northern China. METHODS: A total of 1144 subjects (aged from 5 to 68 years) visiting our clinic from June to October 2011 underwent intradermal testing using a panel of 25 allergen sources. Subjects with positive skin responses to any pollen were further tested for their serum concentrations of IgE antibodies against Artemisia vulgaris, Ambrosia artemisiifolia, and Humulus scandens, and against the purified allergens, Art v 1 and Amb a 1. RESULTS: Of 1144 subjects, 170 had positive intradermal reactions to pollen and 144 donated serum for IgE testing. The prevalence of positive intradermal responses to pollens of Artemisia sieversiana, Artemisia annua, A. artemisiifolia, and H. scandens was 11.0%, 10.2%, 3.7%, and 6.6%, respectively. Among the intradermal positive subjects, the prevalence of specific IgE antigens to A. vulgaris was 58.3%, to A. artemisiifolia 14.7%, and to H. scandens 41.0%. The prevalence of specific IgE antigens to the allergen Art v 1 was 46.9%, and to Amb a 1 was 11.2%. The correlation between the presence of IgE antibodies specific to A. vulgaris and to the Art v 1 antigen was very high. Subjects with A. artemisiifolia specific IgE also had A. vulgaris specific IgE, but with relatively high levels of A. vulgaris IgE antibodies. There were no correlations between the presence of IgE antibodies to H. scandens and A. vulgaris or to H. scandens and A. artemisiifolia. CONCLUSIONS: The intradermal prevalence of weed pollen sensitization among allergic subjects in northern China is about 13.5%. Correlations of specific IgE antibodies suggest that pollen allergens from Artemisia and Humulus are independent sources for primary sensitization.