Changes in Skin Test Aeroallergen Sensitization in Mexico Over the Past 14 Years and According to Climate.

Introduction: Aeroallergen exposure has an intra- and extra-domiciliary component and varies according to climatological zones. Mexico is a large country with a great variety of climates. A previous study (2009) evaluated skin prick test results (SPT) in different regions. In this study, we compare previous sensitization patterns from 14y ago with current ones and compare them between different climatological zones. Methods: Mexican allergists were asked to share their last 100 SPT results in patients with respiratory allergy. Clinics were grouped in (semi)humid vs (semi)dry zones. Results were analyzed nationwide and compared to the 2009 results, calculating odds ratio (OR) and 95% confidence intervals (95% CIs), with p <0.05 as cut-off. Similarly, we compared (semi)humid versus dry zones. Results: We collected 2915 SPT results from 28 clinics (19 cities). Dermatophagoides was the most frequently sensitizing allergen. There was a significant increase in SPT positivity from 2009 to 2023 in both in- and outdoor aeroallergens (OR 1.26-2.65, 95% CI from 1.06-1.50 to 1.99-3.52). Comparing dry-humid zones, sensitization to pollen from Oleaceae, Fagaceae (p < 0.0001 all) and most weeds is more frequent in humid zones, as are Dermatophagoides and cockroach (both p < 0.0001). Eucalyptus, mesquite, and all grass pollen sensitizations predominate in dry zones (p < 0.05-0.0001). There are no differences in sensitization to cat or dog between zones. Conclusion: We found a general increase in SPT sensitization over the past fourteen years, suggesting that this is probably not only due to climate change. The different sensitization profile throughout the country was mainly related to humidity. Repeating epidemiologic SPT studies over the years could help tracking changes in allergen sensitization over time.

Global Asthma Network Phase I study in Mexico: prevalence of asthma symptoms, risk factors and altitude associations-a cross-sectional study.

BACKGROUND: Global Asthma Network (GAN) was established in 2012 as a development to the International Study of Asthma and Allergies in Childhood to improve asthma care globally. OBJECTIVE: To survey asthma, allergic rhinitis and atopic dermatitis in primary and secondary school children and to investigate and evaluate its prevalence, severity, management and risk factors in Mexico. METHODS: GAN Phase I is a cross-sectional, multicentre survey carried out in 15 centres corresponding to 14 Mexican cities throughout 2016-2019 using the validated Spanish language version of the GAN Phase I questionnaires. The questionnaires were completed by parents of 6-7-year-old primary school pupils (school children) and by 13-14-year-old adolescents. RESULTS: A total of 35 780 school children and 41 399 adolescents participated. Wheezing ever prevalence was 26.2% (95% CI 25.8% to 26.7%) in school children and 23.9% (95% CI 23.4% to 24.3%) in adolescents. The corresponding frequencies for current wheeze were 10.2% (95% CI 9.9% to 10.5%) and 11.6% (95% CI 11.2% to 11.9%). In school children, the risk factors for current wheeze were rhinitis (OR 4.484; 95% CI 3.915% to 5.134%) and rash symptoms (OR 1.735; 95% CI 1.461% to 2.059%). For adolescents, rhinitis symptoms (OR 3.492; 95% CI 3.188% to 3.825%) and allergic rhinitis diagnosis (OR 2.144; 95% CI 1.787% to 2.572%) were the most significant. For both groups, there was a negative relation with centres' sea level altitude higher than 1500 m above mean sea level (p<0.005). CONCLUSIONS: The most important risk factors for asthma symptoms in both age groups were the presence of rhinitis and rash symptoms or diagnosis. On the other hand, sea level altitude higher than 1500 metres was a protective factor.

[Allergic bronchopulmonary aspergillosis. A report of a case and literature review]. / Aspergilosis broncopulmonar alérgica. Comunicación de un caso y revisión de la bibliografía.

Allergic bronchopulmonary aspergillosis is a world rare disease with a prevalence between 1 and 2%. It presents in moderate-severe asthma and cistic fibrosis patients. The diagnosis is made in the basis of Rossenberg and Greenberg criteria that can be essential or non essential. We present the case of a 3-year-old boy with allergic bronchopulmonary aspergillosis without bronchiectasies and with a good response to corticosteroids. His mother complained of two years of nasal obstruction, purulent rinorrea, nasal pruritus, sneezing, chronic cough and recurrent wheezing, twice to thrice a month. He also occasionally had vomits and diarrhea in relation with strawberries, banana, cow's milk and chocolate. We made the diagnosis of asthma, allergic rhinitis, sinusitis, and probably food allergy. We treated him with step approach of ICS according to GINA 2006, albuterol PRN, and elimination diet, with bad response. Laboratory exams: Blood white cells with eosinophilia (6%), total serum IgE: 1684 ng/L, aspergillus skin prick test: 4mm, serum IgG-Aspergillus fumigatus: 2.3 mcg/mL, serum IgE-Aspergillus fumigatus: negative, chest roentgenographic parahiliar and apical infiltrates, and chest computed tomography without bronchiectasies. We added prednisone to the treatment for four months, and we observed a very good response; he is now in treatment as mild persistent asthma with ICS low doses. ABPA must be suspected in patients with moderate-severe persistent asthma and a skin prick test positive to Aspergillus fumigatus regardless the age. The treatment with oral corticosteroids is the mainstream of management, and most of the patients have a good response, as we observed with this patient.