Allergic disorders including allergic dermatological diseases especially atopic dermatitis (AD), rhino-conjunctivitis, asthma, food, and drug allergies are common chronic morbidities in pediatric patients.
Though the exact pathogenesis of allergic disorders is not yet defined, it appears that genetic and environmental factors play a role in their development. In addition to physical discomfort, chronic allergic disorders in early childhood may cause mental and behavioral problems such as Attention deficit hyperactivity disorder (ADHD) and Autism spectrum disorder (ASD).
ADHD is a common neurobehavioral disorder characterized by inattention and hyperactivity that appear before the age of 12. Some symptoms and signs can be difficulty organizing tasks and activities, losing things necessary for tasks or activities (school assignments, pencils, books, tools, or toys), easily distracted by extraneous stimuli, difficulty sustaining attention in tasks or play activities, excessive talking, difficulty waiting in lines or awaiting turn in games or group situations, interrupting or intruding on others
ASD is a complex neurodevelopmental disorder characterized by deficits in social interaction, language communication with repetitive problems. Some symptoms and signs may be developmental regression, absence of smiling when greeted by parents and other familiar people, language delays and deviations.
What’s the relation between allergic and neurobehavioral disorders?
As was shown for allergic disorders, the prevalence of ADHD and ASD has steadily increased over the past decades. Furthermore, as was reported for allergic disorders, genetic and environmental factors were shown to play a role in the pathogenesis of ADHD and ASD. Indeed, several studies did investigate the association between allergic disorders and ADHD and/or ASD with controversial results.
Shay Nemet, MD, of the Kaplan Medical Center in Rehovot, Israel, and colleagues did retrospective study analyzing data from 117,022 consecutive children diagnosed with at least one allergic disorder (asthma, conjunctivitis, rhinitis, drug, food, or skin allergy) diagnosed by establish criteria of specialist doctors and 116,968 children without allergies in the Clalit Health Services pediatric database. The children had been treated from 2000 to 2018; the mean follow-up period was 11 years.
The children who were diagnosed with one or more allergies (mean age, 4.5 years) were significantly more likely to develop ADHD (odds ratio [OR], 2.45), ASD (OR, 1.17), or both ADHD and ASD (OR, 1.56) than were the control children who did not have allergies. Children diagnosed with rhinitis (OR, 3.96) and conjunctivitis (OR, 3.63) were the most likely to develop ADHD.
This study expands our understanding of these conditions and their interrelationships, it also brings up many additional questions such as whether some patients were treated and managed well for allergies while others were not , has an importance to develop or not these conditions and opens a new segment of research.
Also , provides strong evidence for the association between allergic disorders in early childhood and the development of ADHD. The risk of those children developing ASD was less significant. More studies are needed to confirm this data.
Shay Nemet,Ilan Asher,Israel Yoles,Tuvia Baevsky,Zev Sthoeger, (June 17, 2022). Early childhood allergy linked with development of attention deficit hyperactivity disorder and autism spectrum disorder. Pediatric Allergy and Immunology. Retrieved from : https://onlinelibrary.wiley.com/doi/10.1111/pai.13819