Data on the psoriasis incidence and prevalence in the Italian population are limited, and a timely and accurate understanding of the disease epidemiology is needed. This ad hoc study investigated psoriasis incidence and lifetime prevalence in a representative sample (n = 14,705) of the Italian population. Information on lifetime history of skin disorders with details about their onset, duration, and treatment was collected. Psoriasis incidence showed a bimodal distribution pattern, with peaks in age classes characteristic of early-onset (35-44 years) and late-onset (65-74 years) psoriasis. Late-onset psoriasis showed some variations according to the sex, with females being diagnosed earlier than males. Lifetime prevalence of psoriasis was 2.7% (95% confidence interval: 2.5-3.0): it increased to 3.5% at age 60-64 years, then decreased steadily after age 64, to 1.7% at age > 74 years. This decrease, despite a peak in incidence rates, after age 64, may suggest a higher mortality rate among psoriasis patients in older age classes, compared to the general population.
Keywords: age-classes; incidence; lifetime prevalence; mortality; psoriasis.