epidemiology of psoriasis

Last edited 08/2019 and last reviewed 03/2022

Epidemiology

• 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

Reference:

• 1. Smith C.H, Barker J.N.W.N. Psoriasis and its management. BMJ 2006;333:380-384
• 2. Langley R.G.B et al. Psoriasis: epidemiology, clinical features, and quality of life. Annals of the Rheumatic Diseases 2005;64(2)
• 3. NICE (September 2017). Psoriasis - the assessment and management of psoriasis