epidemiology of psoriasis

Last edited 08/2019 and last reviewed 07/2021


  • Psoriasis is universal in occurrence (1), affecting males and females equally
  • Prevalence varies with race and geography
    • it is greatest (3%) in northern Europe and Scandinavia and lowest in North American Indians (0.5%)
    • around 2% of the population in the UK is affected by psoriasis (1)

  • there is a clear genetic link established by HLA, family and twin studies, especially in those whose disease had an early onset and in patients with a positive family history (1)

  • according to a number of large studies a bimodal age of onset has been documented with the first peak from 15-20 years and the second at 55 -60 years (2)
    • onset is most common between 15-40 years of age. It is rare under 10 years. The mean is 28 years
    • a seronegative arthropathy occurs in about 7% of patients

  • NICE suggest (3):
    • is uncommon in children (0.71%) and the majority of cases occur before 35 years
      • plaque psoriasis is characterised by well-delineated red, scaly plaques that vary in extent from a few patches to generalised involvement
        • by far the most common form of the condition (about 90% of people with psoriasis)
        • other types of psoriasis include guttate psoriasis and pustular (localised or generalised) forms
      • distinctive nail changes occur in around 50% of all those affected and are more common in people with psoriatic arthritis
    • several studies have also reported that people with psoriasis, particularly those with severe disease, may be at increased risk of cardiovascular disease, lymphoma and non-melanoma skin cancer