Jorge Luna-Pech

Normocaloric Diet Improves Asthma-Related Quality of Life in Obese Pubertal Adolescents

Background: Restrictive, very low-energy diets focused on rapid weight loss have proven to be effective in improving asthma outcome in obese patients, but their use in children and pubescents is controversial due its potential consequences in growth. More conservative, normocaloric schemes are suggested as a more suitable dietary approach for these patients. Methods: A randomized clinical trial was run of 51 pubertal adolescents with asthma and obesity, who were allocated to either an interventional 28-week program of normocaloric diet based on normal requirements for height and meal planning (n = 26) or a non-interventional (free diet) control group (n = 25). Asthma-related quality of life (AR-QOL, assessed by the Standardized Pediatric Asthma Quality of Life Questionnaire, PAQLQ[S]) and clinical indicators of asthma control were measured before and after the intervention period. Results: Diet intervention was associated with a significant improvement in AR-QOL in relation to baseline (Δ PAQLQ[S] scores) compared with controls, both in overall score (p < 0.001) and its subdomains (activity limitation, p < 0.001; symptoms, p < 0.002; emotional function, p < 0.001). The group with normocaloric diet observed a significant decrease in body mass index z-score, which correlated positively with the improvement in AR-QOL (Spearmans r = 0.51, p < 0.01), in addition to have significantly fewer events of acute attacks of asthma and nighttime awakenings, plus a non-significant reduction in the use of inhaled corticosteroids. No significant changes were observed in the pulmonary function tests. Conclusion: The normocaloric dietary intervention was associated with improvement of AR-QOL and some aspects of asthma control. Such structured dietary programs could probably have a role as a complementary non-pharmacological therapeutic strategy in obese pubertal adolescents with asthma.

Allergen sensitization linked to climate and age, not to intermittent-persistent rhinitis in a cross-sectional cohort study in the (sub)tropics

BackgroundAllergen exposure leads to allergen sensitization in susceptible individuals and this might influence allergic rhinitis (AR) phenotype expression. We investigated whether sensitization patterns vary in a country with subtropical and tropical regions and if sensitization patterns relate to AR phenotypes or age.MethodsIn a national, cross-sectional study AR patients (2-70 y) seen by allergists underwent blinded skin prick testing with a panel of 18 allergens and completed a validated questionnaire on AR phenotypes.Results628 patients were recruited. The major sensitizing allergen was house dust mite (HDM) (56%), followed by Bermuda grass (26%), ash (24%), oak (23%) and mesquite (21%) pollen, cat (22%) and cockroach (21%). Patients living in the tropical region were almost exclusively sensitized to HDM (87%). In the central agricultural zones sensitization is primarily to grass and tree pollen. Nationwide, most study subjects had perennial (82.2%), intermittent (56.5%) and moderate-severe (84.7%) AR. Sensitization was not related to the intermittent-persistent AR classification or to AR severity; seasonal AR was associated with tree (p < 0.05) and grass pollen sensitization (p < 0.01). HDM sensitization was more frequent in children (0-11 y) and adolescents (12-17 y) (subtropical region: p < 0.0005; tropical region p < 0.05), but pollen sensitization becomes more important in the adult patients visiting allergists (Adults vs children + adolescents for tree pollen: p < 0.0001, weeds: p < 0.0005).ConclusionsIn a country with (sub)tropical climate zones SPT sensitization patterns varied according to climatological zones; they were different from those found in Europe, HDM sensitization far outweighing pollen allergies and Bermuda grass and Ash pollen being the main grass and tree allergens, respectively. Pollen sensitization was related to SAR, but no relation between sensitization and intermittent-persistent AR or AR severity could be detected. Sensitization patterns vary with age (child HDM, adult pollen). Clinical implications of our findings are dual: only a few allergens –some region specific- cover the majority of sensitizations in (sub)tropical climate zones. This is of major importance for allergen manufacturers and immunotherapy planning. Secondly, patient selection in clinical trials should be based on the intermittent-persistent and severity classifications, rather than on the seasonal-perennial AR subtypes, especially when conducted in (sub)tropical countries.

Debates in Allergy Medicine: Allergy skin testing cannot be replaced by molecular diagnosis in the near future

Percutaneous skin prick tests (SPT) have been considered the preferred method for confirming IgE-mediated sensitization. This reliable and minimally invasive technique correlates with in vivo challenges, has good reproducibility, is easily quantified, and allows analyzing multiple allergens simultaneously. Potent extracts and a proficient tester improve its accuracy.Molecular-based allergy diagnostics (MA-Dx) quantifies allergenic components obtained either from purification of natural sources or recombinant technology to identify the patient’s reactivity to those specific allergenic protein components. For a correct allergy diagnosis, the patient selection is crucial. MA-Dx has been shown to have a high specificity, however, as MA-Dx testing can be ordered by any physician, the pre-selection of patients might not always be optimal, reducing test specificity. Also, MA-Dx is less sensitive than in vitro testing with the whole allergen or SPT. Secondly, no allergen-specific immunotherapy (AIT) trial has yet shown efficacy with patients selected on the basis of their MA-Dx results. Thirdly, why would we need molecular diagnosis, as no molecular treatment can yet be offered? Then there are the practical arguments of costs (SPT highly cost-efficient), test availability for MA-Dx still lacking in wide areas of the world and scarce in others. As such, it is hard physicians can build confidence in the test and their interpretation of the MA-Dx results. In conclusion: as of now these techniques should be reserved for situations of complex allergies and polysensitization; in the future MA-Dx might help to reduce the number of allergens for AIT, but trials are needed to prove this concept.

National clinical practice guidelines for allergen immunotherapy: An international assessment applying AGREE-II

Since 1988, numerous allergen immunotherapy guidelines (AIT‐GLs) have been developed by national and international organizations to guide physicians in AIT. Even so, AIT is still severely underused.

Consenso mexicano para el diagnóstico y tratamiento de la dermatitis atópica en adolescentes y adultos

Busqueda sistematica de la literatura en PubMed y GREAT. Con apoyo metodologico y utilizando el metodo Delphi se desarrollo un consenso formal entre 16 expertos en dermatologia y alergologia, basandose en la evidencia actual y su aplicabilidad en el contexto mexicano. A parte de una comunicacion electronica intensa, se discutieron los puntos en desacuerdo en dos reuniones presenciales.BACKGROUND The diagnostic approaches and therapeutic strategies of atopic dermatitis (AD) are generally inconsistent among physicians and health institutions. OBJECTIVE To develop a consensus statement among experts to reduce the variations in practice regarding the diagnosis and treatment of patients ≥ 12 years with AD to improve their care. METHODS Systematic literature search in PubMed and GREAT. With methodological support and using the Delphi method, a formal consensus was developed among 16 experts in Dermatology and Allergology, based on the current evidence and its applicability in the Mexican context. Apart from intense electronic communication, several issues of disagreement were discussed in two face-to-face meetings. RESULTS The clinical experts reached consensus on 46 statements related to the definition, classification, diagnostic strategies and treatment of AD. For the diagnosis we suggest the Williams criteria and for severity scoring the SCORAD (by the doctor) and POEM (by the patient). In addition to general care and treatment education (workshops), we suggest four steps for treatment, depending on severity: 1. Topical treatment with anti-inflammatory agents (and systemic: antihistamines/antileukotrienes -low level evidence-) 2. Phototherapy, 3. Cyclosporin A and 4. Dupilumab, with the possibility of managing this biological earlier on if a fast effect is needed. In extrinsic AD we suggest evaluating the addition of allergen immunotherapy or an elimination diet, if there is an IgE-mediated respiratory or food allergy, respectively. CONCLUSION The panel of experts reached consensus on relevant aspects of AD with a focus on the transcultural adaptation of recent evidence.