Epidemiology of psoriasis

Epidemiology

• Psoriasis is universal in occurrence (1), affecting males and females equally
• Prevalence varies with race and geography
  • it is greatest in regions with older populations and lowest in those with younger populations (2)
  • around 2% of the population in the UK is affected by psoriasis with the highest prevalence in white adults (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 (3)
  
  
• 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 (1):
  • 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 (4) (5)

Reference:

1. Psoriasis: The assessment and management of psoriasis. NICE Clinical Guideline (October 2012 - last updated September 2017)

2. Parisi R et al. National, regional, and worldwide epidemiology of psoriasis: systematic analysis and modelling study. BMJ. 2020 May 28;369:m1590.

3. Rahman P, Elder JT. Genetic epidemiology of psoriasis and psoriatic arthritis. Ann Rheum Dis. 2005 May

4. Psoriasis and metabolic syndrome: a systematic review and meta-analysis of observational studies. J Am Acad Dermatol. 2013 Apr;68(4):654-62.

5. Gelfand JM et al. The risk of lymphoma in patients with psoriasis. J Invest Dermatol. 2006 Oct;126(10):2194-201.