IGHE and obesity due to melanocortin 4 receptor deficiency: During this time, they were more likely to acquire Type I hypersensitivity which reflecting more T helper 2 lymphocyte (Th2) and consequently immunoglobulin E (IgE) driven response to allergen exposure.[63] Adenotonsillar hypertrophy (AH) was a common comorbidity of pediatric AR, it was reported that 92.6% of AR children also suffered AH .[61] Furthermore, AH is the main cause of OSAS for children aged 3 to 6, yet adults patients were often caused by obesity.[64] This meta-analysis showed no significant difference in the prevalence of AR in OSA and non-OSA patients (children and adults).