Onset Feature Analysis Of Psoriasis Vulgaris

Background Psoriasis (OMIM: *177900) is a common, chronic and recurrent, inflammatory skin disease. Both genetic and environmental factors play important roles in the pathogenesis of psoriasis. Psoriasis vulgaris (PV) is the most frequent clinical type.Objective To explore the differences in onset features, such as onset age, disease severity, affected sites, onset season and other environmental factors between early onset and late onset as well as familial and sporadic PV. To investigate if genetic and environmental factors play any potential roles in these two independent groups described above.Methods Eligible data from 990 patients with PV were collected by a uniform questionnaire, of which 856 early onset and 134 late onset patients; 210 familial and 780 sporadic patients. All the data were inputted into a database set up by Epi Info 6.0 package (American Center for Disease Control and Prevention, Atlanta, GA, USA). Then the data were statistically analyzed by Statistic Package of Social Science (SPSS 10.0 Inc, Chicago, IL, USA).Results 1. Early onset PV patients had severer clinical manifestation than late onset patients (x~2=7.612, P=0.022). 2. Early onset PV patients had more affected sites than late onset patients (Z=1.974, P=0.048). Compared with late onset PV, early onset PV had a higher affected frequency in thighs (x~2=19.253, PO.001), elbows (x~2=12.453, PO.001), upper arms (x~2=21.613, P<0.001), forearms (x~2=6.884, P=0.009), thorax x~2=10.741, P=0.0071) and abdomen (x~2=4.794, P=0.029). 3. Familial PV patients had earlier onset age than sporadic patients (r=3.585, P<0.001). 4. Familial PV patients had lower onset frequency than sporadic patients in summer (x~2=6.458, P=0.011). 5.