Psoriasis can be classified as mild, moderate, or severe. Given the great variability in the clinical forms of the disease, many different instruments are currently used to assess severity in these patients.1 However, all of these methods have limitations. Currently, the most used instruments are the Psoriasis Area Severity Index (PASI), body surface area (BSA), Investigator's Global Assessment scale (IGA), and Dermatology Life Quality Index (DLQI). In 2005, Finlay proposed the rule of tens (PASI, BSA or DLQI>10) as a way to define severe psoriasis,2 but this is far from being a dogma and numerous thresholds and other considerations (prior treatment, site affected, comorbidities, etc.) have been proposed by scientific societies as ways of classifying severity in psoriasis. In recent years, the use of the DLQI has come to the fore,3 and in this issue Llamas-Velasco et al.4 propose a table combining PASI and DLQI as a way to classify severity rapidly and easily in clinical practice. The novel aspect of the proposed classification is that does not require information on the BSA and it only considers psoriasis to be mild if the patient has a PASI score less than 7 and a DLQI score under 5. Only time will tell whether this proposal will prove successful.