BACKGROUND: There is accumulating evidence that early onset psoriasis (EOP; presenting at or before 40 years of age) and late onset psoriasis (LOP; presenting after 40 years of age) are different diseases.
OBJECTIVES AND METHODS: We aimed to identify potential differences between EOP and LOP by assessing immunocytochemistry involved (PP) and uninvolved (PN) skin (n=31) and demographics, psoriasis phenotype and psychological parameters (n=340) in a cross-sectional study. We categorized patients who developed psoriasis before age 40y in the EOP group, whilst those whose psoriasis occurred after age 50y were included in the LOP group.
RESULTS: Immunocytochemistry revealed (17 EOP; 14 LOP) a greater lymphocytic infiltrate in PP skin of EOP than LOP (p=0.03), with a higher epidermal CD4(+) /CD8(+) ratio in LOP (1.3) compared to EOP (0.5; p=0.002). In 340 psoriasis patients (278 EOP; 62 LOP), we found a lower association with a positive 1(st) or 2(nd) degree family history of psoriasis (35.6% vs 62%; OR 0.33, 95% CI 0.18-0.59) and lower likelihood of having parents with EOP (OR=0.093, 95% CI 0.012-0.74) in LOP compared with EOP. EOP patients were more likely to have received biologic therapy (13.3%, EOP vs 3.5% LOP; P=0.042), whilst LOP patients had a higher likelihood of having type 2 diabetes (adjusted OR 3.43, 95%CI 1.004-11.691) and autoimmune thyroiditis (adjusted OR 5.05, 95%CI 1.62-15.7). LOP patients also had greater anxiety than EOP (mean HADS-A score LOP 8±5; EOP 5±5, p=0.006).
CONCLUSIONS: Our findings provide further evidence for the difference between EOP and LOP. This article is protected by copyright. All rights reserved.