Matthias Augustin

OBJECTIVE: To systematically review and provide information on the incidence of psoriasis and quantify global, regional, and country specific estimates of its prevalence. DESIGN: Systematic review and meta-analysis. DATA SOURCES: Medline, Embase, Web of Science, SciELO, Korean Journal Databases, Russian Science Citation Index, WPRIM, SaudiMedLit, Informit, IndMed, and HERDIN were searched systematically from their inception dates to October 2019. METHODS: Studies were included if they reported on the incidence or prevalence of psoriasis in the general population. Incidence data were summarised descriptively, whereas bayesian hierarchical models were fitted to estimate the global, regional, and country specific prevalence of psoriasis. RESULTS: 41 164 records were identified and 168 studies met the inclusion criteria. In adults, the incidence of psoriasis varied from 30.3 per 100 000 person years (95% confidence interval 26.6 to 34.1) in Taiwan to 321.0 per 100 000 person years in Italy. The prevalence of psoriasis varied from 0.14% (95% uncertainty interval 0.05% to 0.40%) in east Asia to 1.99% (0.64% to 6.60%) in Australasia. The prevalence of psoriasis was also high in western Europe (1.92%, 1.07% to 3.46%), central Europe (1.83%, 0.62% to 5.32%), North America (1.50%, 0.63% to 3.60%), and high income southern Latin America (1.10%, 0.36% to 2.96%). CONCLUSIONS: Eighty one per cent of the countries of the world lack information on the epidemiology of psoriasis. The disease occurs more frequently in adults than in children. Psoriasis is unequally distributed across geographical regions; it is more frequent in high income countries and in regions with older populations. The estimates provided can help guide countries and the international community when making public health decisions on the appropriate management of psoriasis and assessing its natural history over time. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42019160817.

The most commonly used tool for self-report of pruritus intensity is the visual analogue scale (VAS). Similar tools are the numerical rating scale (NRS) and verbal rating scale (VRS). In the present study, initiated by the International Forum for the Study of Itch assessing reliability of these tools, 471 randomly selected patients with chronic itch (200 males, 271 females, mean age 58.44 years) recorded their pruritus intensity on VAS (100-mm line), NRS (0-10) and VRS (four-point) scales. Re-test reliability was analysed in a subgroup of 250 patients after one hour. Statistical analysis showed a high reliability and concurrent validity (r>0.8; p<0.01) for all tools. Mean values of all scales showed a high correlation. In conclusion, high reliability and concurrent validity was found for VAS, NRS and VRS. On re-test, higher correlation and less missing values were observed. A training session before starting a clinical trial is recommended.

The aim of this study was to evaluate the visual analogue scale (VAS) as a method of pruritus assessment. A total of 310 subjects with pruritic dermatoses (148 Caucasian subjects and 162 Asian subjects) were recruited. The patients assessed pruritus intensity using the horizontal and vertical VAS, numeric rating scale (NRS) and verbal rating scale (VRS). All scales showed very good reproducibility (intraclass coefficient (ICC) > 0.8). No significant differences were found between the horizontal and vertical VAS (5.3 ± 2.9 vs. 5.3 ± 3.0 points, p = 0.34). Using NRS, patients rated their pruritus significantly higher than with VAS (5.7 ± 2.6 points, p < 0.01). VRS showed the highest correlation with NRS (R = 0.82, p < 0.001), followed by horizontal (R = 0.75, p < 0.001) and vertical VAS (R=0.74, p < 0.001). Based on detailed analysis following VAS categories were proposed: 0 = no pruritus, > 0-< 4 points = mild pruritus, ≥ 4-< 7 points = moderate pruritus, ≥ 7-< 9 points = severe pruritus, and ≥ 9 points = very severe pruritus. In conclusion, the VAS is a valuable method of pruritus measurement.

BACKGROUND: Psoriasis is a common disease affecting all age groups. In contrast to adult psoriasis, only few studies on the epidemiology of childhood psoriasis have been published. OBJECTIVES: Assessment of prevalence and comorbidities of juvenile psoriasis in Germany based on health insurance data. METHODS: Data were collected from a database of about 1.3 million nonselected individuals from a German statutory health insurance organization which covers all geographical regions. Individuals with psoriasis were identified by ICD-10 codes applied to all outpatient and inpatient visits. The present analysis consists of all patients who were enlisted throughout the year 2005. The diagnosis of psoriasis was registered whenever there was at least one documented patient contact using code L40.* and subcodes. Comorbidities were also evaluated by ICD-10 diagnoses. RESULTS: In total, 33 981 patients with the diagnosis of psoriasis were identified. The prevalence in 2005 was 2.5%. The total rate of psoriasis in children younger than 18 years was 0.71%. The prevalence rates increased in an approximately linear manner from 0.12% at the age of 1 year to 1.2% at the age of 18 years. The overall rate of comorbidity in subjects with psoriasis aged under 20 years was twice as high as in subjects without psoriasis. Juvenile psoriasis was associated with increased rates of hyperlipidaemia, obesity, hypertension, diabetes mellitus, rheumatoid arthritis and Crohn disease. CONCLUSIONS: Psoriasis is a common disease in children. Like in adults, it is associated with significant comorbidity. Increased attention should be paid to the early detection and treatment of patients affected.