Early- and late-onset psoriasis: a cross-sectional clinical and immunocytochemical investigation.

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: We aimed to identify potential clinical and immunocytochemical differences between EOP and LOP.

METHODS: We assessed immunocytochemistry in involved (PP) skin and uninvolved skin (n = 31) and demographics, psoriasis phenotype and psychological parameters (n = 340) in a cross-sectional study.

RESULTS: Immunocytochemistry revealed (17 EOP, 14 LOP) a greater lymphocytic infiltrate in PP skin of EOP compared with LOP (P = 0·03), with a higher epidermal CD4+ : CD8+ ratio in LOP (1·3) compared with EOP (0·5) (P = 0·002). In 340 patients with psoriasis (278 EOP, 62 LOP), we found an association with a positive first or second degree family history of psoriasis [62·0% vs. 35·6%, adjusted odds ratio (OR) 8·32, 95% confidence interval (CI) 1·90-36·52] and a higher likelihood of having parents with EOP (adjusted OR 10·34, 95% CI 1·32-81·83) in the EOP group. Patients with EOP were more likely to have received biological therapy (13·3% EOP vs. 3·5% LOP, P = 0·042), while patients with LOP 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). Patients with LOP also had greater anxiety than patients with EOP (mean Hospital Anxiety and Depression Scale-A score LOP 8 ± 5, EOP 5 ± 5; P = 0·006).

CONCLUSIONS: Our findings provide further evidence for the difference between EOP and LOP.