Timothy Grass Pollen Sensitization in Asthmatic Egyptian Children

Abstract

Background: Allergic diseases are considered a major problem for healthcare systems in both developed and developing countries. Longitudinal epidemiologic studies have shown an increased prevalence of sensitization to common allergens, and increased prevalence of asthma, atopic dermatitis, food allergy, and allergic rhinitis in children. The increase in allergies is a phenomenon that is being observed in all fast-developing countries. For a long time, science has taken as a starting point that solely a genetic predisposition is a precondition for the development of an allergy. Today, knowledge of environmental factors that can alter genes or the transcription of genes in the cells, has improved. Aim of the Work: We aimed to investigate the rate of sensitization to Timothy grass pollen in a group of asthmatic Egyptian children in relation to other markers of disease expression. Our ultimate objective was to add information to the map of aeroallergen sensitization in our country. Patients and Methods: This analytical cross sectional study was conducted on children with bronchial asthma following up at the Pediatric Allergy and Immunology Clinic, Children's Hospital, Ain Shams University in the period from September 2017 to March 2018. The sample included 100 asthmatic patients who were enrolled consecutively. Patients were classified into intermittent and persistent Asthma according to the 2009 VA/DoD asthma management guidelines. Results: The current study revealed a high frequency of Timothy grass pollen (TGP) sensitization representing 61% of the studied sample. The diameter of wheal in sensitized children ranged between 3-7 mm with a median (IQR) of 4 (3- 4). None of our subjects had wheal diameter ≥ 8 mm, which denotes severe reaction. In our study, Patients with persistent asthma were more prone to be TGP sensitized (80.3%) than those with intermittent asthma (19.7%). Sensitized children with persistent asthma showed larger wheal diameter (median= 4 mm, range: 4-7 mm) than those with intermittent asthma who showed smaller diameter (median= 3.5 mm, range: 3-4 mm). Conclusion: Sensitization to TGP might point a persistent phenotype of pediatric asthma and may be linked to severity and need to step up and/or add on therapeutic options.