Idiopathic acute pancreatitis (IAP)-a review of the literature and algorithm proposed for the diagnostic work-up of IAP.

Background and objective: This narrative review addresses idiopathic acute pancreatitis (IAP) and its epidemiology, diagnosis, clinical course and treatment during the last decade. As there is no previously validated protocol for finding the aetiology of acute pancreatitis (AP), the primary aim of this study is to find, describe and unify evidence about the diagnostic work-up of AP to diagnose the true IAP. By finding the aetiology with the highest possible yield it may be possible to reduce recurrent AP (RAP) episodes and related morbidity and thereby decrease health care costs and possibly improve patients' quality of life.

Methods: This narrative review includes articles retrieved from PubMed search with publications from 2013-2023. Cross references were used when found relevant.

Key content and findings: The rates of aetiologies of AP and the diagnostics performed behind these numbers vary widely between different studies, time periods and different geographical regions, as there is no unified algorithm in diagnostic work-up of IAP. In this study, we describe an up-to-date summary of epidemiology, diagnostic course and treatment of IAP, and propose an algorithm of IAP diagnostics in light of recent scientific studies and their outcomes and address possible treatments of IAP.

Conclusions: Although aetiology is key for AP management, there is still no validated protocol for aetiological diagnosis. IAP is relevant due to its recurrence rate and possible evolution to chronic pancreatitis. We still need more studies addressing this topic and evaluating new diagnostic protocols with advanced tests and treatment strategies in true IAP.