Non-Immunoglobulin-E mediated gastrointestinal food allergy in children: diagnosis, management and clinical impact

Background: Despite all research published in the last decades, the prevalence of food allergy in the paediatric population has continued to increase and is nowadays recognized as a significant public health problem. In the United Kingdom, studies have found that between 2.2% and 5.5% of the infants in the first year of life present with proven food allergies, with the prevalence of cow’s milk protein allergy, the most common form of non-IgE food allergies, ranging between 1.9% and 4.9%. The diagnosis of non-IgE mediated food allergy is a real challenge due to its delayed onset, with symptoms occurring hours to days after ingestion of the culprit and mainly affecting the gastrointestinal tract. Allergy tests have shown limited use in these patients, and the diagnosis relies heavily on the recognition of symptoms and an allergy-focused history. The treatment is based on diet elimination, which can lead to the development of nutritional disorders and negative impact on the child’s quality of life. Objectives: The aims of the publications included in this thesis are, first, to prospectively investigate the required length of elimination diet to achieve symptom improvement during the diagnostic process; second, to evaluate the knowledge of primary health care professionals about diagnosis and management of cow’s milk protein allergy, to compare with parents views and opinions, and to better understand diagnosis tools, treatment and tolerance in infants diagnosed with nonIgE food allergies; third, to evaluate possible impacts of the elimination diet on growth and nutrients deficiencies; and fourth, to analyse the potential impact of nonIgE mediated gastrointestinal allergies on the quality of life of the affected children and their families. Methods: Children with suspected non-IgE mediated gastrointestinal food allergies were recruited and followed prospectively at a large tertiary gastroenterology department in the United Kingdom (UK) from December 2011 to November 2013. This study was designed to investigate the impact of non-IgE mediated food allergies on quality of life, as well as to establish symptoms, children’s growth and the characteristics and impact of dietary elimination. The knowledge and journey of diagnosis of cow’s milk protein allergy among general practitioners were studied via surveys. Eosinophilic colitis in infants was studied through a systematic review. II Results: In non-IgE mediated gastrointestinal food allergies the required time to achieve symptom improvement following the initiation of the elimination diet was four weeks in 98% of our patients. All symptoms individually and collectively have statistically improved after commencing the elimination diet (p