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.

Compromising between European and US allergen immunotherapy schools: Discussions from GUIMIT, the Mexican immunotherapy guidelines.

BACKGROUND: Allergen immunotherapy (AIT) has a longstanding history and still remains the only disease-changing treatment for allergic rhinitis and asthma. Over the years 2 different schools have developed their strategies: the United States (US) and the European. Allergen extracts available in these regions are adapted to local practice. In other parts of the world, extracts from both regions and local ones are commercialized, as in Mexico. Here, local experts developed a national AIT guideline (GUIMIT 2019) searching for compromises between both schools. METHODS: Using ADAPTE methodology for transculturizing guidelines and AGREE-II for evaluating guideline quality, GUIMIT selected 3 high-quality Main Reference Guidelines (MRGs): the European Academy of Allergy, Asthma and Immunology (EAACI) guideines, the S2k guideline of various German-speaking medical societies (2014), and the US Practice Parameters on Allergen Immunotherapy 2011. We formulated clinical questions and based responses on the fused evidence available in the MRGs, combined with local possibilities, patient's preference, and costs. We came across several issues on which the MRGs disagreed. These are presented here along with arguments of GUIMIT members to resolve them. GUIMIT (for a complete English version, Supplementary data) concluded the following. RESULTS: Related to the diagnosis of IgE-mediated respiratory allergy, apart from skin prick testing complementary tests (challenges, in vitro testing and molecular such as species-specific allergens) might be useful in selected cases to inform AIT composition. AIT is indicated in allergic rhinitis and suggested in allergic asthma (once controlled) and IgE-mediated atopic dermatitis. Concerning the correct subcutaneous AIT dose for compounding vials according to the US school: dosing tables and formula are given; up to 4 non-related allergens can be mixed, refraining from mixing high with low protease extracts. When using European extracts: the manufacturer's indications should be followed; in multi-allergic patients 2 simultaneous injections can be given (100% consensus); mixing is discouraged. In Mexico only allergoid tablets are available; based on doses used in all sublingual immunotherapy (SLIT) publications referenced in MRGs, GUIMIT suggests a probable effective dose related to subcutaneous immunotherapy (SCIT) might be: 50-200% of the monthly SCIT dose given daily, maximum mixing 4 allergens. Also, a table with practical suggestions on non-evidence-existing issues, developed with a simplified Delphi method, is added. Finally, dissemination and implementation of guidelines is briefly discussed, explaining how we used online tools for this in Mexico. CONCLUSIONS: Countries where European and American AIT extracts are available should adjust AIT according to which school is followed.

[Mexican clinical practice guidelines of immunotherapy 2011]. / Guía Mexicana de Práctica Clínica de Inmunoterapia 2011.

BACKGROUND: Several international guidelines on immunotherapy exist, but they only apply partially in Mexico. The Mexican guideline of immunotherapy dates from 1998. OBJECTIVES: To establish clinical recommendations and suggestions for Allergy residents and specialists for skin testing and allergen immunotherapy based on evidence and Mexican expert opinion, according to the GRADE system. METHODS: The guidelines were developed following the methodology of a guideline for clinical practice starting with the formulation of clinical questions, in the context of Mexican environmental conditions and morbidity, with the participation of allergists from all regions of the country. External validation was obtained. Its development followed three steps: 1. formulation of 24 clinical questions. 2. Search for consensus on the answers among members of the Regional chapters of both Mexican Colleges of Allergists (CMICA and COMPEDIA) during regional meetings. 3. Literature search for articles related to the questions and grading of its quality according to GRADE. RESULTS: Based on the regional consensus, 116 articles and the safety, patient acceptance/ comfort and cost clinical recommendations and suggestions were developed on basic aspects of skin testing, subcutaneous and sublingual immunotherapy (patient preparation, vial preparation and application schedules) and the treatment of eventual adverse reactions. CONCLUSIONS: A clinical guideline was developed respecting particular methodology, validated by CMICA and COMPEDIA for its implementation among Mexican allergists. Several aspects deserve further study to improve scientific evidence. KEYWORDS: Allergen immunotherapy, subcutaneous immunotherapy, sublingual immunotherapy, skin testing, allergy diagnosis, rhinitis, asthma, atopic dermatitis, house dust mite, pollens, anaphylaxis, adrenaline, Mexico.

Frequency of acute systemic reactions in patients with allergic rhinitis and asthma treated with sublingual immunotherapy.

BACKGROUND: Several studies have demonstrated the efficacy and safety of sublingual immunotherapy in the treatment of respiratory allergy. OBJECTIVE: To determine the frequency of systemic adverse reactions in patients treated with standardized extracts of sublingual immunotherapy. METHODS: Allergic patients with rhinitis with or without asthma and sensitized to at least 1 allergen were included. Increasing doses of standardized allergens were administered until reaching an average dose accumulated of 7,200 U after 26 weeks of treatment. Adverse events were graded according to the European Academy of Allergy and Clinical Immunology immunotherapy position paper. RESULTS: Forty-three patients with a median age of 11 years (interquartile range, 8-20 years) were included. All the patients had allergic rhinitis, and 63% had asthma; they were sensitized mostly to Dermatophagoides pteronyssinus and Dermatophagoides farinae. Four patients (9%) presented with an immediate and 1 (2%) with a late systemic reaction. In total, 7 systemic reactions occurred in 23,154 doses, and all were associated with wheezing or worsening of nasal symptoms (grade 2); in addition, 1 patient had angioedema and urticaria (grade 3). CONCLUSIONS: In this group, systemic reaction frequency was 11.6%, and all were classified as grade 2 or 3. Further assessments in larger samples of patients are required in the context of randomized controlled trials.

[Safety of immunotherapy and skin tests with allergens in children younger than five years]. / Inocuidad de la inmunoterapia y pruebas cutáneas con alergenos en niños menores de cinco años de edad.

BACKGROUND: It has been demonstrated that specific immunotherapy, in addition to its preventive properties, is an effective and safe therapeutic resource for allergic asthma, allergic rhinitis and allergy to insect's venom; however, its use in patients younger than five years has been limited due to the risk of systemic reactions. OBJECTIVES: To know the frequency and severity of systemic reactions in children younger than five years and to know if a greater risk of systemic reactions in this group of age is real. PATIENTS AND METHODS: We included 239 patients from one to five years of age with diagnosis of allergic disease and verified its specific sensitivity with skin tests or RAST and were treated with specific immunotherapy. A detailed registry of the application of specific immunotherapy was kept from every patient, with special attention to any symptom present during the first 30 minutes post application of specific immunotherapy or skin test. RESULTS: From January 1996 to June 2005, 6,689 injections were applied to 239 patients. Only one patient of 36 months of age presented with a delayed systemic reactions characterized by generalized hives, itching, runny nose, water eyes, 90 minutes post injection. The patient was under treatment with Dermatophagoides farinae and pteronissinus (house dust mites) with a dose of 1AU for allergic rhinitis. The systemic reactions were treated easily and without complications with a single dose of intramuscular epinephrine (0.15cc, 1:1000) and oral antihistamine. CONCLUSION: Patients younger than five years are not in greater risk of systemic reactions from specific immunotherapy or skin tests than the older children or adults and the treatment of those systemic reactions does not imply greater difficulty. Because of its preventive properties, safety and effectiveness in lowering the severity of symptoms of allergic diseases, we concluded that specific immunotherapy should be considered at early age, prescribed and administered only by specialist in pediatric allergy and in optimal conditions of safety.

[Non-fatal systemic reactions caused by immunotherapy and skin tests]. / Reacciones sistémicas no fatales por inmunoterapia y pruebas cutáneas.

OBJECTIVE: The frequency and severity of systemic reaction (SR) from skin test (ST) and specific immunotherapy (SIT) in Mexico, have not been published before. In order to know that frequency and severity, a prospective study was performed in the Allergy Clinic at General Hospital of Matamoros from August, 1991 to July, 1996. SR from ST and SIT were monitored. Symptoms were recorded with respect to the time of onset, involvement of respiratory tract or skin and presence of hypotension. RESULTS: 65,397 injections were given to 1,149 patients; there were 25 SR in 20 patients (1:2,615 injections or 1:57 patients). Time of onset was between 10 and 30 minutes. SR were present more frequently during maintenance. There was a 3:1 rate in female patients and a predominance in the 15 to 24 age group. CONCLUSIONS: In Matamoros, Tamps., Mexico, frequency and severity of SR from ST and SIT is not different from published data. Small children are not in higher risk. Immunotherapy is a safe therapeutic procedure on expert hands.