Friday, March 14, 2014
When children experience pain, they may either confront the pain or learn to fear pain and avoid certain activities. This behavior is termed fear-avoidance. Confronting the pain has been thought to lead to pain resolution while learned avoidance may persist and cause chronic pain and disability that can disrupt normal childhood activities.
Researchers at the University of North Carolina School of Medicine and the University of Washington tested this fear-avoidance model of pain in 129 children with Inflammatory Bowel Disease (IBD) in remission and in 200 children with Functional Abdominal Pain (FAP; ages 8-18). In IBD pain is caused by gut inflammation and alternated with periods of disease remission. Pain can persist after inflammation has subsided. In FAP pain occurs in the absence of a specific cause. Thus, in both FAP and IBD patients in remission, no disease pathology explains the pain.
Miranda van Tilburg, PhD, associate professor of medicine in UNC's Division of Gastroenterology and Hepatology, is lead author of the study, which was presented Thursday, March 13, at the annual meeting of the American Psychosomatic Society in San Francisco.
"Chronic abdominal pain is very common among children," van Tilburg said. "How a child feels about and reacts to the pain is as important as the severity of pain in determining how much the pain will affect a child’s life."
Evidence that fear and avoidance predict disability was found only in children with FAP. In these children, more severe pain was associated with increased catastrophizing (worrying about pain while feeling helpless to do anything about it). Catastrophizing in turn was associated with believing that pain is a threat, which was then associated with increased disability and pain.
Thus if children experience helplessness and a sense of threat in response to pain, they may become fearful of the pain, and avoid activities such as going to school or participating in sports. Over time the combination of fear and avoidance may lead to a heightened experience of pain and more disruption of normal activities.
Fear avoidance appears to contribute to disability and pain in children with Functional Abdominal Pain but not in children with Inflammatory Bowel Disease in remission.
"Children with FAP and IBD in remission are thought to have similar causes for their pain," van Tilburg said. "We hypothesized that fear avoidance would also have a similar influence on pain outcomes in both disorders, but this is not what we found."