Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage1 and it is one of the major symptoms in arthritis.2-4 Pain is also the sensory modality that alerts patients so that it leads to protective responses. Pain also informs the patient that there is a potential noxious threat, which brings him or her to the doctor for diagnosis and treatment of his illness (or ailment). Unfortunately, a warning signal like acute pain can turn into chronic pain and in this stage pain itself can be the most dominant symptom and threat for the quality of life of the patient. In the pathogenesis of inflammatory pain, receptors sensitive for noxious stimuli generated as a consequence of inflammation, have a role. These receptors, called nociceptors, activate predominantly unmyelinated, small diameter sensory nerves, mediating nociceptive information to higher order neurones in the dorsal horn of the spinal medulla. On spinal as well as supraspinal level, the nociceptive signal is modulated by regulating pathways (fig 1). Besides these regulating pathways there are many substances that are able to stimulate directly and/or sensitise primary afferent nociceptive fibres (table 1).5 6

Children express pain in a different way than adults do.7This is often interpreted as if children feel less or even no pain as in the case of neonates. The idea that newborns and children differ fundamentally from adults in the perception of pain, has led to approaches …