Clinical study of psoriasis occurring over the age of 60 years: is elderly-onset psoriasis a distinct subtype?

Background: Previous studies demonstrated clinical differences of early- and late-onset psoriasis. However, epidemiological data and clinical characteristics of psoriasis occurring in geriatric patients have been rarely studied.

Objective: Assessment of epidemiology and clinical features of psoriasis first occurring over the age of 60 years, so-called elderly-onset psoriasis, based on clinical data.

Materials And Methods: Among 4049 patients visiting our psoriasis clinic for the last 27 years, patients were first divided into early- (onset age before 30 years) and late-onset psoriasis (onset age after 30 years) based on our previous studies. Then, patients of late-onset psoriasis were further divided into middle age-onset group (onset age between 30 and 60 years) and elderly-onset group (onset age over 60 years). Clinical characteristics of elderly-onset psoriasis were compared with early- and middle age-onset groups. We acquired the data both by physician's assessments and patients' responses.

Results: Elderly-onset patients comprised 3.2% of total patients, 129 out of 4049. They have shown a lower incidence of family history (P < 0.05). The severity assessed by PASI score, body surface extent, and activity of individual lesions demonstrated that psoriasis of the elderly-onset group was generally milder compared with early- and middle age-onset groups (P < 0.05). In clinical phenotypes, the proportion of guttate type and generalized pustular psoriasis type decreased remarkably, while that of erythroderma type increased (P < 0.05). There was a significant change in the body part of origin comparing early- and middle age-onset groups (P < 0.05). The proportion of scalp increased, while that of knee-elbow and trunk decreased significantly (P < 0.05). Patients' subjective sensation of disease course improved statistically comparing early- and middle age-onset groups (P < 0.05). There was no significant change in the degree of pruritus on psoriatic lesions and nail involvement (P > 0.05).

Conclusion: The elderly-onset group demonstrated milder disease courses and some changes in clinical phenotypes and body part of origin compared with early- and middle age-onset groups. Therefore, it seems that patients whose onset of psoriasis was over the age of 60 years might have distinct clinical features in some clinical aspects.