J Can Assoc Gastroenterol 2019 Feb 2;2(Suppl 1):S49-S67. Epub 2018 Nov 2.
Canadian Gastro-Intestinal Epidemiology Consortium Ottawa, Canada.
Canada has among the highest rates of childhood-onset IBD in the world. Over 7000 children and youth under 18 years old are living with IBD in Canada, and 600 to 650 children under 16 years old are diagnosed annually. While the peak age of onset of IBD is highest in the second and third decades of life, over the past two decades incidence has risen most rapidly in children under 5 years old. The treatment of children with IBD presents important challenges including therapeutic choices, risk of adverse events to medications, psychosocial impact on the child and family, increased cost of health care and the implications of the transition from pediatric to adult care. Despite the unique circumstances faced by children and their families, there is a lack of research to help understand the causes of the rising incidence and the best therapies for children with IBD. Scientific evidence-and specifically clinical trials of pharmaceuticals-are too often extrapolated from adult research. Health care providers must strive to understand the unique impact of childhood-onset IBD on patients and families, while researchers must expand work to address the important needs of this growing patient population.
Highlights: In 2018, there are over 7000 children and youth under 18 years old living with IBD in Canada, and 600 to 650 young children (under 16 years) diagnosed every year.The number of children in Canada living with IBD is growing rapidly, increasing 50% in the first decade of the 21st century.Inflammatory bowel disease is still rare in children younger than 5 years of age, but it is occurring in such young children more often than in the past.Children with IBD are different from adults. For example, delayed growth, extent of disease and difficulties encountered during adolescence are all unique to the pediatric experience.We must consider the psychosocial well-being of both children and their families, given that caring for a child with IBD can affect the global functioning of families.Treatment approaches in children sometimes differ from those in adults. However, to date, all effective therapies in adults have also been effective in children. There is great need for clinical trials of new therapies in children so that they have equal access to emerging treatments and optimal pediatric dosing can be established.
Key Summary Points: Rates of new diagnoses in children under 16 years old were increasing most rapidly in Ontario (increased 5.8% per year) and Quebec (increased 2.8% per year).Nova Scotia has the highest rate of pediatric IBD, with lower rates in Quebec and Ontario. However, even Ontario and Quebec have higher rates of pediatric IBD than most countries in the world.Inflammatory bowel disease is caused by the interaction between genes, environmental risk factors, the microbiome and the immune system. Since children experience shorter exposures and possibly fewer environmental risk factors, the interaction between these risk factors and genes may be stronger with childhood-onset IBD.The microbiome is mostly established in early childhood and is affected by a number of factors such as environment, diet, pregnancy/delivery factors and antibiotic use. Changing the microbiome to a healthier state may prevent the disease and may also be a novel therapeutic target to treat active inflammation in children with IBD.Children with IBD are different from adults. They are more likely to have extensive involvement of their intestines, especially in ulcerative colitis, and are at risk for growth impairment, osteoporosis, and psychosocial difficulties affecting their families.Children with IBD may incur more direct health costs for treatment of their IBD compared with adults. However, this is not universally true for all children because those who are very young at diagnosis (2 to 6 years old) may have milder disease or respond better to medications. This may result in decreased use of the health system, fewer hospitalizations and less risk of surgery than older children and adolescents.The choice of treatments for children with IBD may be different from that of adults. It is important to consider pediatric-specific disease considerations. Delayed growth, deficient bone development, psychosocial well-being of the child and family, disease extent, disease severity and risk of poor outcomes during transition from pediatric to adult health care are all important considerations when choosing the best treatment for children and adolescents.While the medications used are similar in children and adults with IBD, research to assess the effectiveness and safety of these medications in children (especially very young children) is sparse.Children with IBD may be more responsive to treatment than adults because they are more likely to have inflammatory (rather than stricturing) disease. Therefore, treating the inflammation earlier in the course of disease may prevent long-term complications such as strictures, obstruction, need for surgery and need for hospitalization.Some medications used in IBD have unique or more pronounced risks in children compared with adults. For example, chronic prednisone use is associated with growth impairment and stunting in children. Anti-TNF biologics are the only medications proven to improve growth in children with Crohn's disease and should be considered early in the course of disease in patients with severe IBD or those with marked growth impairment at the time of diagnosis.Some medications are used differently, depending on the sex of the patient. For example, azathioprine (with or without biologics) is associated with hepatosplenic T cell lymphoma (and other forms of lymphoma) in adolescent and young adult males more often than females. Methotrexate is associated with birth defects in the growing fetus and therefore should be avoided in adolescent and adult women of child-bearing age who are not using two or more forms of birth control.A small group of children, typically presenting in the first two years of life, have single-gene mutations that cause an IBD-like bowel disease and also immune system dysfunction. These patients may not respond to traditional IBD medications and may require therapies such as bone marrow transplant. Canada is leading research efforts to investigate, diagnose and treat this small group of very vulnerable children.Inflammatory bowel disease (especially when it is active) can affect school attendance, social interactions, concentration and learning. Schools should be aware of the implications of IBD and make allowances for these factors in children with active inflammation and symptoms to optimize their chances of academic and social success.
Gaps In Knowledge And Future Research Directions: We have limited knowledge on what causes IBD in children and why rates are rising most rapidly in young children. We must better understand the interaction between genes, the environment, the immune system and the microbiome in order to better prevent and treat the disease.Treatment for infants with IBD-like illnesses and single-gene mutations is limited. Future research should work towards identifying these children and learning how best to treat them.There are few clinical trials for biologics in children, and most exclude very young children. Support for such trials is important to understand whether the treatments work, how they should optimally be given and whether they are safe for young children with IBD.Considering the effectiveness of dietary therapies for children with Crohn's disease (exclusive enteral nutrition), we should work to understand how diet affects intestinal inflammation and the microbiome in order to better use dietary therapies to treat IBD.Health services researchers, health care providers and policy-makers should work together to understand why variation in the access to treatment and medical care of children with IBD exists. We must work together to improve the quality of care provided to these children and ensure they have the highest quality of care.Psychosocial implications of IBD in children and their families are of importance to long-term and overall well-being. Children with a chronic, incurable disease are at risk for mental illness associated with their disease. We should design interventions to improve the psychosocial status, mental health and quality of life of children with IBD and their families.While nonlive immunizations are safe for children with IBD, we must understand how to improve their effectiveness in children who are immunosuppressed. While the peak onset of IBD occurs in the second or third decades of life, the frequency of new diagnoses in younger children is rising rapidly. In Canada, the fastest growing group of newly diagnosed people with IBD are children aged under 5 years (termed 'very early onset [VEO] IBD). These young children have not been included in clinical trials of new medications, resulting in a lack of scientific evidence of safety and effectiveness of treatments in this group, and clinical experience has shown that they do not respond to usual medications used for the majority of children with IBD. Providing children with IBD with high-quality care and social support also poses other challenges to care providers, families and the health system. This section will focus on the unique challenges facing Canadian children with IBD. A complete overview of the objectives, working committees and methodology of creating the report can be found in the supplemental file, Technical Document.