BACKGROUNDSeverity of psoriasis appears to be multidimensional and its assessment in everyday clinical practice requires a complex holistic approach.OBJECTIVESTo develop evidence-based recommendations to assess severity of plaque-type psoriasis in adult patients in everyday clinical practice.METHODSA scientific committee (10 members identified on the basis of their expertise in psoriasis) using Delphi methodology selected eight questions in three domains: severity, health-related quality of life (HR-QoL) and comorbidities. Three systematic literature reviews (one per domain) of all studies published between January 1980 and June 2009 were performed based on Pub-Med, Cochrane and Embase database. Selected articles were systematically reviewed and evidence appraised according to the Oxford Levels of Evidence. On June 2009, a group of 44 French dermatologists both hospital and office based participated in a meeting including three separate rounds of discussions, plenary sessions, and modified Delphi technique votes. Recommendations for clinical practice based on systematic review and clinical experience were formulated by the group. Subsequently, agreements among the participants regarding these recommendations as well as potential impact on clinical practice were evaluated.RESULTSA total of 10 642 references were identified, of which 154 articles were analysed. Ten key recommendations on the assessment of psoriasis severity were formulated: three recommendations relating to severity assessment, three recommendations relating to HR-QoL (including the use of the Dermatology Life Quality Index [DLQI] in clinical practice) and four recommendations relating to comorbidities (including systematic screening for peripheral or axial inflammatory joint damage, regardless of psoriasis severity).CONCLUSIONSTen recommendations to assess the severity of plaque-type psoriasis in adult patients in daily practice were developed. The recommendations are based on systematic appraisal of available evidence. They were developed and supported by a panel of dermatologists, which enhances their validity and practical relevance.