Who gets psoriasis?

Psoriasis affects about 1 to 5% of the population worldwide, varies from 0.91% in the United States to 8.5% in Norway. It is estimated to affect 1-2% of the population in Singapore. Peak onset is often at 15–25 years and 50–60 years. It affects man and woman equally. When one parent has psoriasis, 8% of his or her offspring develop psoriasis; when both parents have psoriasis, 41% of their children develop psoriasis. Psoriatic arthritis occurs in 10 to 25% of patients.

What causes psoriasis?

Psoriasis is classified as T-cell mediated autoimmune skin disease. In simple language,psoriasis is multifactorial, for example, genetic and environmental reasons, may trigger our own cells mistakenly attack our own skin.

Factors that aggravate psoriasis:

  1. Bacterial or virus infections
  2. Streptococcal tonsillitis
  3. Injuries such as cuts, abrasions, sunburn
  4. Sun overexposure
  5. Obesity
  6. Smoking
  7. Alcohol
  8. Hot bath
  9. Emotional stress
  10. Stay late night
  11. Medications such as lithium, beta blockers, antimalarials, nonsteroidal anti-inflammatory drug
  12. Stopping oral steroids or strong topical corticosteroids.

How is psoriasis diagnosed?

Psoriasis is diagnosed by its clinical features. If necessary, diagnosis is supported by typical skin biopsy findings.

Current Western Treatment for Psoriasis:

  • Topical Application
  1. Emollients
  2. Coal tar preparations
  3. Dithranol
  4. Salicylic acid
  5. Vitamin D analogue (calcipotriol)
  6. Topical corticosteroids
  7. Immunosuppressants (tacrolimus, pimecrolimus)
  • Phototherapy
  1. Narrowband UVB
  2. Broadband UVB
  3. Photochemotherapy (PUVA)
  • Systemic Suppressive drugs
  1. Methotrexate
  2. Ciclosporin
  3. Acitretin
  4. Mycophenolate
  5. Apremilast
  6. Hydroxyurea
  7. Azathioprine
  8. 6-mercaptopurine
  9. Systemic corticosteroids
  • Biologics Immunosuppressant
  1. Anti-tumour necrosis factor-alpha (anti-TNFα) antagonists (infliximab, adalimumab and etanercept)
  2. The interleukin (IL)-12/23 antagonist (ustekinumab)
  3. IL-17 antagonists (secukinumab, ixekizumab, brodalumab)


  1. A. David Burden and Brian Kirby. Psoriasis and Related Disorders. Chapter 35. In. Christopher Griffiths, Jonathan Barker, Tanya Bleiker, Robert Chalmers & Daniel Creamer. eds (2016). Rook’s Textbook of Dermatology (9th Ed.) London. Wiley-Blackwell
  2. Johann E. Gudjonsson & James T. Elder. Psoriasis. Chapter 28 In. Jean Bolognia Julie Schaffer Lorenzo Cerroni. eds (2017). Dermatology: 2-Volume Set. (4th Ed.) Elsevier.

Tangs Treatment

Dear friend, I pray that you may enjoy good health and that all may go well with you, even as your soul is getting along well.

— 3 John 1:2