Oral allergy syndrome amongst young Mexicans: prevalence and associated factors.

Summary: Background. Oral allergy syndrome (OAS) is the most common food allergy manifestation amongst adults. However, population studies aimed at estimating its prevalence and associated factors are scarce in Mexi-co. Objectives. To establish the prevalence of OAS in a sample of university students and to describe their clinical characteristics and its associated factors. Methods. From a sample group made up of 25,269 university students, the data corresponding to 1,200 students aged 18 to 25 was analyzed with a cross-sectional approach. A structured questionnaire was used to identify OAS, its symptoms and related foods, and the personal history of atopic diseases. The associations between variables were calculated through logistical regression analysis. Results. The prevalence of OAS was 3.4%, with a 95% confidence interval (95% CI) of 2.5 to 4.6. The main oral symptoms reported were lip pruritus, edema and the sensation of pharyngeal oppression. Among the extra-oral complaints were: reddish coloration of the skin, body pruritus, abdominal pain, and abdominal bloating. The foods that were most frequently associated with OAS were fruits (68.5%), vegetables (22.0%) and seafood (19.3%). Through multivariate analyses, allergy to pollen and latex were found to be associated with OAS, OR 3.29; 95%: CI 1.53 to 7.10 and OR 5.53; 95% CI: 1.08 to 28.2, respectively. Conclusions. Notably, the prevalence of OAS varies according to the geographic area. Personal histories of allergy to pollen or latex were the main factors linked to OAS.

Self-reported hypersensitivity and allergy to foods amongst Mexican adolescents: Prevalence and associated factors.

BACKGROUND: The prevalence of food allergy is on the rise on a global scale. OBJECTIVE: To determine the prevalence of food hypersensitivity (FHS) and probable food allergy (PFA), as well as the foods and factors associated with these occurrences. METHODS: A cross-sectional study was carried out among 1992 adolescents (aged 15-18 years). Each adolescent answered a structured questionnaire. A multivariate analysis was used to identify the association between the variables. RESULTS: The prevalence of FHS was 10.6% (the most commonly associated foods were shrimp, cow's milk and avocado) and the PFA was 7.8% (shrimp, cow's milk and pecan). The prevalences of oral allergy syndrome, food-associated urticaria and systemic reaction were 4.9%, 3.6% and 1.5%, respectively. The following factors were associated with FHS: personal history of asthma (OR 1.63; 95% CI: 1.11-2.41), allergic rhinitis (OR 2.60; 95% CI: 1.75-3.87), atopic dermatitis (OR 2.07; 95% CI: 1.25-3.43), maternal history of asthma (OR 1.80; 95% CI: 1.02-3.16), atopic dermatitis (OR 6.11; 95% CI: 2.45-15.29), and female sex (OR 1.89; 95% CI: 1.38-2.59). PFA was associated with a personal history of asthma (OR 1.65; 95% CI: 1.06-2.56), allergic rhinitis (OR 2.46; 95% CI: 1.56-3.88), atopic dermatitis (OR 2.02; 95% CI: 1.15-3.54), paternal allergic rhinitis (OR 2.52; 95% CI: 1.15-5.51), maternal atopic dermatitis (OR 7.46; 95% CI: 2.93-19.00), and female sex (OR 1.89; 95% CI: 1.31-2.72). CONCLUSION: The adverse reactions associated with foods among late adolescents are a frequent occurrence, and the most commonly associated factor is atopy.

Prolonged breastfeeding and delayed introduction of whole cow's milk into the diet are factors associated with egg sensitization: A matched case-control study.

BACKGROUND: Both breastfeeding and the moment at which introduction to solid food occurs have been associated with food allergy. OBJECTIVE: To evaluate whether prolonged breastfeeding and the delayed introduction of whole cow's milk into an infant's diet are factors that can be associated with egg sensitization. METHODS: This was a hospital-based case-control study, matched by age and sex: each study group comprised 97 atopic children. Additionally, logistic regression was used to identify the factors associated with egg protein sensitization. RESULTS: The most common type of allergic disease among both groups was allergic rhinitis. After adjusting for possible confounding variables, a delayed introduction to whole cow's milk decreased the odds of egg protein sensitization; OR=0.16 (95% CI: 0.07-0.36, p<0.0001). Notably, breastfeeding during the first six months of life, regardless of whether it was the only milk an infant drank, increased the risk for sensitization to chicken eggs; OR=5.54 (95% CI: 2.41-12.7, p<0.0001). CONCLUSION: Prolonged breastfeeding, regardless of whether it was the only milk an infant drank, greatly increased the risk of egg sensitization. Interestingly, a delayed introduction to whole cow's milk was associated with a reduced possibility of becoming sensitized to eggs. Further studies are required to elucidate these findings.

Recommendations for the prevention and diagnosis of asthma in children: Evidence from international guidelines adapted for Mexico.

BACKGROUND: With the availability of high-quality asthma guidelines worldwide, one possible approach of developing a valid guideline, without re-working the evidence, already analysed by major guidelines, is the ADAPTE approach, as was used for the development of National Guidelines on asthma. METHODS: The guidelines development group (GDG) covered a broad range of experts from medical specialities, primary care physicians and methodologists. The core group of the GDG searched the literature for asthma guidelines 2005 onward, and analysed the 11 best guidelines with AGREE-II to select three mother guidelines. Key clinical questions were formulated covering each step of the asthma management. RESULTS: The selected mother guidelines are British Thoracic Society (BTS), GINA and GEMA 2015. Responses to the questions were formulated according to the evidence in the mother guidelines. Recommendations or suggestions were made for asthma treatment in Mexico by the core group, and adjusted during several rounds of a Delphi process, taking into account: 1. Evidence; 2. Safety; 3. Cost; 4. Patient preference - all these set against the background of the local reality. Here the detailed analysis of the evidence present in BTS/GINA/GEMA sections on prevention and diagnosis in paediatric asthma are presented for three age-groups: children with asthma ≤5 years, 6-11 years and ≥12 years. CONCLUSIONS: For the prevention and diagnosis sections, applying the AGREE-II method is useful to develop a scientifically-sustained document, adjusted to the local reality per country, as is the Mexican Guideline on Asthma.

A rural environment does not protect against asthma or other allergic diseases amongst Mexican children.

INTRODUCTION: The commonly held notion that a rural environment decreases the frequency of allergic diseases has proven to be inconsistent amongst children. OBJECTIVE: Our objective was to contrast the prevalence of bronchial asthma (BA), allergic rhinitis (AR), and atopic dermatitis (AD) between children that live in a rural environment and those that live in urban areas. METHODS: We carried out a cross-sectional study amongst children aged six to seven; they were selected through probabilistic, stratified and conglomerated sampling. The prevalence of BA, AR, and AD was identified with the use of the questionnaire provided by The International Study of Asthma and Allergies in Childhood, additionally, we inquired about each child's family history of atopy, their exposure to farm animals, the intake of unpasteurised cow's milk, and the number of siblings related to every child. We used logistic regression and multivariate analysis to determine the correlation between asthma, allergic diseases, and rural environment. RESULTS: We included 189/1003 (18.8%) children from a rural environment, and 814/1003 (81.2%) from an urban area. BA and AR were associated to a family history of atopy (OR=2.15, p=0.001; OR=2.58, p=0.002, respectively). BA was more prevalent in males (OR=1.92, p=0.007). Notably, a higher number of siblings seems to protect against AR (OR=0.45, p=0.008). A paternal history of allergies was associated to AD. CONCLUSIONS: In our study, we were unable to find protective factors in a rural environment that might decrease the prevalence of asthma or allergic diseases.

Prevalence and factors associated to peanut allergy in Mexican school children.

BACKGROUND: In our country, the prevalence and the factors associated to peanut allergy are unknown, a health problem that has been emerging worldwide. OBJECTIVE: To establish the prevalence and the factors that are associated to peanut allergy amongst school children. METHODS: This is a population-based cross-sectional study. We included 756 children aged 6-7 years. The children's parents were questioned about their peanut intake habits. A structured questionnaire was applied, it included questions regarding peanut intake; family and personal history of asthma; rhinitis; and atopic dermatitis. Allergic reactions to peanuts were registered as: probable, convincing and systematic. The statistical analyses included logistical regression models to look for associated factors. RESULTS: Males were 356/756 (47.1%). Peanut allergy prevalence: probable reaction: 14/756 (1.8%), convincing reaction: 8/756 (1.1%) and systemic reaction: 3/756 (0.4%). Through multivariate analysis, the presence of symptoms of allergic rhinitis (OR=4.2 95% CI 1.3-13.2) and atopic dermatitis (OR=5.2; 95% CI 1.4-19.5) during the previous year, showed significant association to probable peanut reaction. The former year, the presence of atopic dermatitis was the only variable that was substantially associated to a convincing reaction (OR=7.5; 95% CI 1.4-38.4) and to a systematic reaction (OR=45.1; 95% CI 4.0-510.0), respectively. CONCLUSIONS: The reported prevalence of peanut allergy was consistent with that found in previous studies; symptoms of allergic rhinitis and atopic dermatitis were identified as associated factors to peanut allergy.

Prevalence of oral allergy syndrome in children with allergic diseases.

INTRODUCTION: The oral allergy syndrome (OAS) is a particular type of food allergy rarely explored in the paediatric population that is already considered an adult problem. OBJECTIVE: Identify the prevalence of OAS, symptoms and pollen species associated with its presence in children affected by allergic diseases. METHODS: A cross-sectional study was conducted. Consecutive sampling included children from 6 to 14 years who needed allergy treatment for the first time. A structured questionnaire was carried out to collect demographic and clinical data and history of OAS. Besides sensitisation to various allergens, the skin prick-by-prick test was performed to corroborate sensitisation to food related to OAS. Prevalence of OAS and its association with pollens was established following the covariate adjusted logistic regression. RESULTS: 267 subjects were included. Overall prevalence of OAS was 8.9% (95%CI 6.1-13.1%). Prevalence of OAS for allergic rhinitis and asthma were 8.8% and 9.1%, respectively. In patients sensitised to pollen, the prevalence ranged from 9.6% to 12.2% depending on the type of pollen. 62.5% of children with OAS were sensitive to pineapple. After adjusting for gender and family history of atopic disease, trees from the Quercus species showed an association with OAS (OR=2.7, 95%CI 1.2-6.2). CONCLUSIONS: OAS is not uncommon in our environment. Pineapple, a typical fruit from the region, was the main food related. Quercus sp., but not birch nor olive, was the pollen associated with this syndrome.

[Bronchial asthma, atmospheric pollution, and weather conditions. Guadalajara, Jal]. / Asma bronquial, contaminación atmosférica y condiciones climatológicas. Guadalajara, Jal.

BACKGROUND: In the last year it has been an increase in the prevalence of asthma, as well as in the air pollution. The effect of air pollution on the respiratory health is still controversial. OBJECTIVE: To determine the relationship between the income to the Emergency Room for asthmatic crisis and the air pollution or weather conditions. MATERIAL AND METHOD: An observational, descriptive, retrospective survey was made with children and adult patients who had an income to the Emergency Room of the Dr. Valentín Gómez Farías Regional Hospital due to an asthmatic crisis, during period between January 1st and December 31 the of 1994, being related to weekly measures of ozone, nitrogen dioxide, carbon monoxide, sulfur dioxide and particulate matter as air pollution, and minimal temperature, minimal percentage of humidity and wind speed, as weather conditions. They was related by autoregression technique using the Epi Info 5 computing system. RESULTS: An amount of 406 incomes to the Emergency Room for asthmatic crisis was recorded, observing an increase during the period between September and November. When compared to the air pollutants and weather conditions measurement, it has found a moderate relation between the increase of income and the nitrogen dioxide quantification, as the highest value. CONCLUSIONS: Air pollution and weather conditions by themselves seem to have a minimal to moderate influence on the incidence of incomes to the Emergency Room for asthmatic crisis.