Columbus, OH - March 2016
Only within the last decade have many pediatric gastroenterologists begun to accept the diagnosis of “functional nausea,” or chronic nausea not associated with any underlying disease. But some remain skeptical, and physicians may ignore or neglect the condition.
A recent review article in the Journal of Pediatric Gastroenterology and Nutrition has collected the current knowledge on the mechanisms and treatment of functional nausea in children to support the conclusion that the condition is real and interventions are possible.
“Functional nausea exists. It is a true entity,” says Carlo Di Lorenzo, MD, senior author of the article and chief of the Division of Gastroenterology, Hepatology and Nutrition at Nationwide Children’s Hospital. “Many doctors and parents are worried that they are missing an underlying organic disease. In some cases, though, the patient isn’t suffering from an ulcer or from gall bladder disease. Instead, the patient is suffering from functional nausea.”
Nausea is typically seen as an early warning of vomiting, or at least an activation of the emetic pathway. Little evidence, however, supports traditional emetic pathways as the model for functional nausea, and functional nausea does not respond well to standard anti-emetic medication.
Instead, recent neuroimaging studies suggest that higher cortical centers are involved in producing the condition. Autonomic dysregulation, gastric function abnormalities and duodenal hypersensitivity may also play a role. Functional nausea that most often manifests in the early morning may be related to an increased sensitivity to cortisol production in the morning as well.
Like other functional gastrointestinal disorders, functional nausea often has psychological comorbidities. Previous studies have found that 70 percent of patients with primary chronic nausea (likely functional nausea) suffered from anxiety. Anxiety is more prevalent in adolescents with chronic nausea, and, in turn, the symptoms combined with the uncertainty of the diagnosis and use of ineffective therapies may lead to higher mental stress in the adolescent population.
One of the difficulties in diagnosing functional nausea is the lack of diagnostic guidelines – the pediatric Rome III Diagnostic Criteria for functional gastrointestinal disorders did not even include a functional nausea category, although the adult criteria do.
The new Rome IV criteria are due to be published this year, and Dr. Di Lorenzo is the chair of the pediatric committee. The 2016 pediatric criteria will include functional nausea, he says.
“It’s often not necessary to do dozens of tests to rule out every possible disease,” says Dr. Di Lorenzo, who is also a professor of clinical pediatrics at The Ohio State University College of Medicine. “You can have a conversation with a patient, take a medical history and make a diagnosis of functional nausea. But the diagnosis and the treatments can be driven by how willing patients and parents are to accept them.”
Some resist the idea that anxiety may play a role in generating the symptom, and that meeting with a psychologist, taking psychotropic medications or alternative measures such as acupuncture, herbal supplements or relaxation therapy could be helpful, Dr. Di Lorenzo says. Family education and the use of simple analogies – including the comparison of functional GI disorders to the headache, a common functional disorder – often are important in treatment.
“Different treatments work on different people,” Dr. Di Lorenzo says. “We can help people with functional nausea, even if it’s not quite as easy as taking a pill for acid indigestion.”
Kovacic K, Di Lorenzo C. Functional nausea in children. Journal of Pediatric Gastroenterology and Nutrition. 2015 Dec 10. [Epub ahead of print]