Pressure pain threshold in children with recurrent abdominal pain

Background: Experimental studies on humans have shown that recurrent pain is associated with altered pain perception. We measured the pressure pain threshold in regions of the body surface in a group of children who had recurrent abdominal pain and in a group of children with chronic or recurrent disease but with no pain. Methods: Each group consisted of 45 boys and 55 girls ranging in age from 5 to 15.8 years. The regions of the body were the trapezius, deltoid, and supraspinous muscles, nine areas on the abdominal wan, and the median part of the tibias. Using an algometer, pressure was applied through a rubber disc with a surface area of I cm(2) at a rate of 0.5 kg/cm(2)/s. The pressure values recorded with the algometer when the children communicated that they started to feel pain were considered as pressure pain thresholds. Results: The pain thresholds were reduced in all regions investigated in children with recurrent pain. The median thresholds for all regions of the patients with and without pain were 1.60 and 2.2 kg/cm(2), respectively. The diseases of children with pain did not influence the pain thresholds. Conclusion: There was an association between recurrent abdominal pain and a lower pressure pain threshold, with no influence of the type of disease, and there was a central nervous system alteration in the perception of pain in these patients.