For multiple reasons, including the demands of ill health, treatment, and readjustment to usual life following periods of medical treatment, children and young people with CHCs are at greater risk of developing psychological problems, especially anxiety [2]. Currently, services for these patients are limited, as are face-to-face and eHealth interventions, particularly those targeted toward health anxiety [3,4]. Partly due to the real dangers associated with the virus, the rapidity of lockdown, and the immediacy of social media, the COVID-19 pandemic has resulted in significantly increased rates of anxiety in the general population. Among those with life-threatening illnesses such as cancer, worries about social isolation, catastrophization about personal health, and guilt about family support have been even greater [5-7]. Studies of children from China have also identified clinginess, distraction, irritability, and fear of asking questions about the pandemic, more so in those who reside in highly affected regions [8]. It is not just those with physical health issues who are vulnerable. A recent UK survey of over 2000 young people with a history of mental health problems found that 51% of participants believed that their mental health had deteriorated due to the pandemic, and many reported increased psychological distress and loneliness [9]. Fortunately, there is emerging evidence suggesting that effective communication and distraction can help to protect children’s psychological health [8,10].

There is some evidence that children with attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD), who usually thrive with predictability and routine, have been more affected by the disruption to routines during the pandemic than other groups. Children with ADHD have been found to display a greater level of symptoms that are related to family stress and can be reduced by establishing predictable new routines [11]. Those with ASD have also been found to exhibit greater behavioral concerns, especially in the face of pre-existing issues [12]. Increased physical activity has been suggested as one mechanism by which increased symptoms can be managed in these patients [13].

Children and young people spend a large proportion of their weekdays at school. Schools provide structure, intellectual stimulation, peer interaction, reliable meals, and access to recreational facilities and health care. Despite attempts to maximize online learning during lockdown, school closures are likely to have many unintended and potentially serious consequences on the psychological and physical health of children and young people [14,15]. Thousands, if not millions, of children from lower socioeconomic backgrounds may be disproportionately affected by school closures and experience food insecurity and inadequate or limited access to online learning [16,17]. Others are likely to engage in increased screen time and sedentary behaviors, just as during longer school holidays [18], placing themselves at risk of unhealthy weight gain [19]. Youth with pre-existing mental health conditions are especially reliant on psychological support services offered through schools and will be unable to access school counsellors, nurses, and social workers [20].

It is well established that increased family stress, financial insecurity, and cumulative risk exposure in childhood are associated with worse mental and behavioral outcomes in children [21,22]. Of particular concern, it is well documented that domestic violence is more likely in the face of chronic family stress such as caring for a child with a CHC. Moreover, chronic family stress further increases following crises such as natural disasters or disease outbreaks associated with economic stress [23-25]. Due to the focus on competing issues, vulnerable children including those with CHCs are often less likely to be identified via routine child health checks and by personnel such as health care professionals or school teachers. Coupled with the significantly reduced number of child protection assessments conducted during lockdown [26], it is likely that COVID-19–associated lockdown, school closures, and family financial insecurity will compound family stress levels and increase the incidence of domestic violence and child abuse [14,27], many of whom unfortunately may not be recognized to receive appropriate support.

During the past few months, a significant decline in general practitioner appointments, specialized care, and pediatric emergency department attendance has been reported in many countries including the United Kingdom, Ireland, Germany, Canada, Australia, China, and Italy [28-35]. In some cases, delays in seeking treatment and lack of specialized care have had devastating effects on children with serious and life-threatening health complications including those of a psychological nature [36,37].

Other reported disruptions to health care services include disruptions to routine child health services, such as developmental screening, vaccinations, and well-child visits, that support psychosocial well-being [31,33]. There is also accumulating evidence to suggest that children with certain CHCs have been negatively impacted by changes to health care systems prioritizing the response to the pandemic, such as inflammatory bowel disease [38], pediatric cancer [39,40], and type 1 diabetes [41].

Previously limited psychological services for children and young people with CHCs are also likely to have been affected by COVID-19–related disruptions. Countries such as Singapore have reported diverting psychological resources for youth with eating disorders to only those considered most urgent and forging partnerships with community services to manage the decrease in access to psychological therapies [42], while other countries such as New Zealand have restricted face-to-face pediatric consult liaison services to inpatients at low risk of COVID-19. In the United Kingdom, 26% of young people with pre-existing mental health problems reported being unable to access psychological support services during the lockdown period [9].

Although some degree of academic pressure may be essential for learning, the chronic stress of regular assignments, presentations, and examinations can have negative effects on students’ physical and psychological health, including precipitating conditions such as anxiety, depression, and eating disorders [43,44]. Associated with the developmentally congruent drive toward conformity, adolescent peer-related stress can also affect students’ health in a gender-related manner [45]. Youth with CHCs experience additional stresses related to disrupted education and peer relationships, readjustment during transitions in and out of the hospital, and the physical limitations of ill health [46]. During lockdown, all these issues are likely to occur less frequently. Additionally, for some, such as children with cystic fibrosis, the normalization of wearing masks may reduce the sense of difference and associated stigma [47].

Many children will be forced to spend weeks, if not months, with their families during lockdown. Given that domestic social capital has been shown to be more influential than school-related social capital and that it is associated with a reduced incidence of behavior problems [48], including in people with chronic illness [49], it is possible that many children and young people with CHCs will benefit from their parents being more available, being more involved in health care routines, and supporting them to deal with COVID-19–related or other health concerns. Family-based therapies for eating disorders [50] and other conditions may also be more effective in the context of greater parental availability. Additionally, evidence from Austria indicates that social connectedness can increase during lockdown and that it is associated with reduced distress and fatigue [51].

Up to 40% of young people with CHCs have issues related to substance abuse [52]. Pandemic-related anxiety, fear, and boredom are likely to increase the drive toward substance-related coping in this subgroup. Smoking and inhaling substances are particularly likely to increase the risk of contracting COVID-19 [53]. Fortunately, these risks are likely to be offset by reduced access to substances and, to a lesser extent, by lower financial independence and greater parental connection [54].

Due to disruptions to routine services, health professionals worldwide have had to rapidly adopt or expand digital health care via Zoom (Zoom Video Communications, Inc), Skype (Skype Technologies), and other servers or platforms. Regulatory barriers to telemedicine have also been amended due to the urgency caused by the pandemic [55]. Despite some of the limitations associated with engagement and physical examination, the necessity for patients to have access to digital devices, and the potential loss of privacy for young people, digital health care is likely to have equitably increased access to health care for many families, especially those living rurally and with limited financial means. It is also likely to have reduced the anxiety experienced by some children in medical settings and allowed health professionals to gain a better understanding of their patients’ living circumstances. The pandemic may provide an additional opportunity to expand the use of existing eHealth interventions such as evidence-based internet cognitive behavioral therapy (iCBT)–based applications, medical support, and self-management interventions [56], and to identify ways for future interventions to improve outcomes for youth with CHCs.

Resilience has been defined as the ability of an individual to withstand adversity [57]. Despite the medically and socially related stresses they experience on a day-to-day basis, most children and adolescents with CHCs manage to live productive and effective lives, thereby demonstrating their inherent resilience [52]. The current pandemic is likely to provide them with additional opportunities to withstand novel concerns about their health; alterations to health care and other routines; increased family stress; and disappointment about missing out on schooling, peer interactions, and leisure activities. With adequate family, social, and health professional support, previous studies have proved that children with CHCs can surmount significant periods of difficulty [58].