Epidemiology and comorbidity of psoriasis in children

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.