title: Pain and chronic pancreatitis: a complex interplay of multiple mechanisms.
abstract: Despite multiple theories on the pathogenesis of pain in chronic pancreatitis, no uniform and consistently successful treatment strategy exists and abdominal pain still remains the dominating symptom for most patients and a major challenge for clinicians. Traditional theories focussed on a mechanical cause of pain related to anatomical changes and evidence of increased ductal and interstitial pressures. These observations form the basis for surgical and endoscopic drainage procedures, but the outcome is variable and often unsatisfactory. This underscores the fact that other factors must contribute to pathogenesis of pain, and has shifted the focus towards a more complex neurobiological understanding of pain generation. Amongst other explanations for pain, experimental and human studies have provided evidence that pain perception at the peripheral level and central pain processing of the nociceptive information is altered in patients with chronic pancreatitis, and resembles that seen in neuropathic and chronic pain disorders. However, pain due to e.g., complications to the disease and adverse effects to treatment must not be overlooked as an additional source of pain. This review outlines the current theories on pain generation in chronic pancreatitis which is crucial in order to understand the complexity and limitations of current therapeutic approaches. Furthermore, it may also serve as an inspiration for further research and development of methods that can evaluate the relative contribution and interplay of different pain mechanisms in the individual patients, before they are subjected to more or less empirical treatment.
authors.affiliation: Jakob Lykke Poulsen, Søren Schou Olesen, Lasse Paludan Malver, Asbjørn Mohr Drewes, Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, DK-9000 Aalborg, Denmark.
authors.forename: Jakob Lykke
authors.initials: JL
authors.lastname: Poulsen
authors.forename: Søren Schou
authors.initials: SS
authors.lastname: Olesen
authors.forename: Lasse Paludan
authors.initials: LP
authors.lastname: Malver
authors.forename: Jens Brøndum
authors.initials: JB
authors.lastname: Frøkjær
authors.forename: Asbjørn Mohr
authors.initials: AM
authors.lastname: Drewes
mesh_terms: D015746:Abdominal Pain / Q000209:etiology* / Q000503:physiopathology / Q000523:psychology / Q000628:therapy; D000818:Animals; D006801:Humans; D059408:Pain Management / Q000379:methods; D010147:Pain Measurement; D058748:Pain Perception; D017288:Pain Threshold; D010179:Pancreas / Q000294:innervation*; D050500:Pancreatitis, Chronic / Q000150:complications* / Q000503:physiopathology / Q000523:psychology / Q000628:therapy; D012307:Risk Factors; D016896:Treatment Outcome; D017833:Visceral Afferents / Q000503:physiopathology*
keywords: Abdominal pain; Chronic pancreatitis; Neuropathy; Pain mechanisms; Sensitization