Abstract: Objective: To investigate the differences of clinical characteristics between early-onset psoriasis (age<40 years) and late-onset psoriasis (age≥40 years). Methods: All the patients with early and late-onset of psoriasis recruited in the study were asked to complete a questionnaires including gender, age, onset age, height, weight, family history, previous history, aggravating factors, nail damage, tongue changes, pruritus, complications. Results: The study included 352 psoriasis (279 early-onset and 73 late-onset). 5.73% early-onset patients and 15.07% late-onset patients had palmoplantar lesions, with a significant difference (χ2=7.170，P=0.007). 9.32% early-onset patients and 23.29% late-onset patients had complications, with a significant difference (χ2=10.528，P=0.001). 73.13% early-onset patients and 44.83% late-onset patients relapsed in the wintert with a significant difference (χ2=12.207,P＜0.01). There were no significant differences in PASI score, SF-36 score and DLQI score (Ps>0.05) between the two groups. Conclusion: There are different clinical characteristics between early-onset psoriasis and late-onset psoriasis.

Key words: psoriasis, early onset, late onset, clinical features, health status