Psoriasis is a chronic, immune-mediated disorder with cutaneous and systemic manifestations and substantial negative effects on patient quality of life. Psoriasis has a strong, albeit polygenic, genetic basis. Whereas approximately half of the accountable genetic effect of psoriasis maps to the major histocompatibility complex, >70 other loci have been identified, many of which implicate nuclear factor-κB, interferon signalling and the IL-23-IL-23 receptor axis. Psoriasis pathophysiology is characterized by abnormal keratinocyte proliferation and immune cell infiltration in the dermis and epidermis involving the innate and adaptive immune systems, with important roles for dendritic cells and T cells, among other cells. Frequent comorbidities are rheumatological and cardiovascular in nature, in particular, psoriatic arthritis. Current treatments for psoriasis include topical agents, photo-based therapies, traditional systemic drugs and biologic agents. Treatments can be used in combination or as monotherapy. Biologic therapies that target specific disease mediators have become a mainstay in the treatment of moderate-to-severe disease, whereas advances in the treatment of mild-to-moderate disease have been limited.

Summary Skin disease can cause severe disability and handicap in children. Measurement of the impact of skin disease on the quality of life is required to aid clinical decision‐making, for clinical research, for audit of paediatric dermatology services, and for political reasons, to aid arguments for more resources for the care of children with skin disease. Adult measures are inappropriate, as the lives of children differ markedly from those of adults. The purpose of this study was to create and initially validate a simple practical questionnaire for use in children. One hundred and sixty‐nine children, aged 3–16 years, attending a paediatric dermatology clinic, wrote down, with the help of their parents, all the ways in which their skin disease affected their lives. One hundred and eleven different aspects were identified; 10 questions were composed to cover these aspects, using a structure similar to the Adult Dermatology Life Quality Index. This draft questionnaire was piloted on two series, totalling 40 children, and minor alterations were made to improve clarity. The Children's Dermatology Life Quality Index (CDLQI) questionnaire (maximum score 30) was then given to a further 233 dermatology paediatric out‐patients (CDLQI mean = 5.1, SD = 4.9), 47 normal controls (mean 0.4, 0.7) and 55 control patients attending a general paediatric clinic (mean 0.7, 2.5). The CDLQI scores for eczema (mean = 7.7, 5.6, n = 47), psoriasis (5.4, 5.0, n = 25) and acne (5.7, 4.4, n = 40), were all highly significantly greater than for moles and naevi (2.3, 2.9, n = 29). The highest mean score was that for scabies (mean = 9.5, 10.5, n = 6). Overall, the highest scoring questions (each maximum score 3) related to symptoms (mean = 1.05, n = 233), feelings (0.90), swimming and sports (0.51), sleep (0.49) and treatment effects (0.47), with the question on effects on friendships (0.18) scoring least. Forty‐six additional patients completed the CDLQI on two occasions, with a 4‐day interval to check reliability of test‐retesting. The standard deviation of the differences between pairs (2.5) was substantially less than the standard deviation of the measurements themselves (before = 4.79, after = 5.08). confirming acceptable repeatability. This study has confirmed the major impact of widespread inflammatory skin disease, in particular atopic eczema, on the quality of life of children. Although further validation is required, the CLDQI provides a new technique for comparative purposes.

Corporate partners of the EDF have been asked to contribute towards this work. GlaxoSmithKline plc. (GSK) and Meda AB have contributed funding for the development of the European evidence-based (S3) guideline for the treatment of acne (update 2016) through an educational grant to the EDF. Sponsors had no influence on the content of the guideline. Support was given independent of any influence on methods or results. Sponsors did not receive any information about methods, group members or likely results. The sources of the funding were not known to the experts of the guideline and were not disclosed before the finalization of the guideline. This is a short summary of the complete version of the S3 European Acne guideline, please see online appendix for full text (Document S1. Long Version) and detailed methods report (DOI: 10.1111/jdv.13783). Expiry date: 31 December 2020 MethodsIn order to weight the different recommendations, the group assigned a 'strength of recommendation'. It considered all aspects of the treatment decision, such as efficacy, safety, patient preference and the reliability of the existing body of evidence. Strength of recommendationIn order to grade the recommendation a "standardized guideline" language was used:

Summary The aim of this survey was to quantify the level of handicap experienced by patients with severe psoriasis, and to assess the value that patients place on their disease using various questionnaire techniques. Dermatologists throughout the U.K. each gave a questionnaire to up to five psoriasis patients, who were either being admitted for in‐patient care or were starting systemic therapy. Three hundred and sixty‐nine questionnaires were completed. Of the 150 patients currently working, 59·3% had lost a mean of 26 days (SD 21·9) from work during the preceding year because of their psoriasis, and of the 180 not working 33·9% attributed not working to their psoriasis. The mean Psoriasis Disability Index (PDI) score was 38·2% (SD 23·3, n= 248), with the mean sub‐scores of the ‘daily activities’ and ‘treatment’ sections being greater than those of the other three sections. Despite having severe psoriasis, the majority of patients felt that it would be worse to have diabetes, asthma or bronchitis than to have psoriasis. Forty‐six, 42 and 32% considered it would be either ‘better’ or ‘the same’ to have diabetes, asthma or bronchitis, respectively. However, in those patients who also had the comparative disease, 87, 80 and 77% considered it would be ‘better’, or ‘the same’ to have the comparative disease. Forty‐nine per cent of patients (n= 362) stated they would be prepared to spend 2 or 3 h each day on treatment if this might result in normal skin for the rest of the day. Three hundred and sixty‐four (98·9%) of patients stated they would prefer to have a complete cure of their psoriasis rather than be given £1000 cash. Seventy‐one per cent (n=336) of patients said they would be prepared to pay £1000 or more, and 38% (n=336) said they would pay £10,000, for a cure for their psoriasis. There was a substantial correlation (0·48) between the PDI score and the amount a patient indicated they would pay for a cure. This survey of patients with severe psoriasis reveals major handicap caused by the disease, and illustrates the extent to which patients would value effective therapy.

<b><i>Aims:</i></b> To determine the minimal clinically important difference (MCID) of the Dermatology Life Quality Index (DLQI) and its responsiveness to change in inflammatory skin diseases. <b><i>Methods:</i></b> A longitudinal study: at stage 1, patients completed the DLQI and a disease severity global question; at stage 2, a global rating of change in quality of life (QoL; Global Rating of Change Questionnaire, GRCQ) was added and used as an anchor to measure the MCID of the DLQI. <b><i>Results:</i></b> 192 patients completed stage 1 and 107 completed stage 2. The mean DLQI score at stage 1 was 9.8 and 7.4 at stage 2 with a mean change of 2.4 (p < 0.0001). 31 patients experienced a ‘small change' in their QoL (±3 and ±2) on the GRCQ. The mean corresponding change in DLQI scores was 3.3, which is regarded as the approximate MCID. <b><i>Conclusions:</i></b> Previous estimates of the MCID of the DLQI have varied from 3 to 5. Although this study demonstrated a MCID of 3.3, we recommend that the MCID in inflammatory skin diseases should be 4.