Psoriasis

Psoriasis
Back and arms of a person with severe psoriasis
Pronunciation
SpecialtyDermatology (primarily);
immunology, rheumatology and other specialties (e.g., cardiology and vascular medicine, nephrology, hepatology/gastroenterology, endocrinology, haematology) (indirectly/by association)
SymptomsRed (purple on darker skin), itchy, scaly patches of skin[3]
ComplicationsPsoriatic arthritis[4]
Usual onsetAdulthood[5]
DurationLong-term[4]
CausesGenetic disease triggered by environmental factors[3]
Diagnostic methodBased on symptoms[4]
TreatmentSteroid creams, vitamin D3 cream, ultraviolet light, immunosuppressive drugs such as methotrexate and biologics[5]
Frequency79.7 million[6] / 2–4%[7]

Psoriasis is a long-lasting, noncontagious autoimmune disease characterized by patches of abnormal skin.[4][5] These areas are red, pink, or purple, dry, itchy, and scaly.[8][3] Psoriasis varies in severity from small localized patches to complete body coverage.[3] Injury to the skin can trigger psoriatic skin changes at that spot, which is known as the Koebner phenomenon.[9]

The five main types of psoriasis are plaque, guttate, inverse, pustular, and erythrodermic.[5] Plaque psoriasis, also known as psoriasis vulgaris, makes up about 90% of cases.[4] It typically presents as red patches with white scales on top.[4] Areas of the body most commonly affected are the back of the forearms, shins, navel area, and scalp.[4] Guttate psoriasis has drop-shaped lesions.[5] Pustular psoriasis presents as small, noninfectious, pus-filled blisters.[10] Inverse psoriasis forms red patches in skin folds.[5] Erythrodermic psoriasis occurs when the rash becomes very widespread, and can develop from any of the other types.[4] Fingernails and toenails are affected in most people with psoriasis at some point in time.[4] This may include pits in the nails or changes in nail color.[4]

Psoriasis is generally thought to be a genetic disease that is triggered by environmental factors.[3] If one twin has psoriasis, the other twin is three times more likely to be affected if the twins are identical than if they are nonidentical.[4] This suggests that genetic factors predispose to psoriasis.[4] Symptoms often worsen during winter and with certain medications, such as beta blockers or NSAIDs.[4] Infections and psychological stress can also play a role.[3][5] The underlying mechanism involves the immune system reacting to skin cells.[4] Diagnosis is typically based on the signs and symptoms.[4]

There is no known cure for psoriasis, but various treatments can help control the symptoms.[4] These treatments include steroid creams, vitamin D3 cream, ultraviolet light, immunosuppressive drugs, such as methotrexate, and biologic therapies targeting specific immunologic pathways.[5] About 75% of skin involvement improves with creams alone.[4] The disease affects 2–4% of the population.[7] Men and women are affected with equal frequency.[5] The disease may begin at any age, but typically starts in adulthood.[5] Psoriasis is associated with an increased risk of psoriatic arthritis, lymphomas, cardiovascular disease, Crohn's disease, and depression.[4] Psoriatic arthritis affects up to 30% of individuals with psoriasis.[10]

The word "psoriasis" is from Greek ψωρίασις, meaning "itching condition" or "being itchy"[11] from psora, "itch", and -iasis, "action, condition".

  1. ^ Jones D (2003) [1917]. Roach P, Hartmann J, Setter J (eds.). English Pronouncing Dictionary. Cambridge: Cambridge University Press. ISBN 978-3-12-539683-8.
  2. ^ "Psoriasis". Merriam-Webster.com Dictionary. Merriam-Webster.
  3. ^ a b c d e f Menter A, Gottlieb A, Feldman SR, Van Voorhees AS, Leonardi CL, Gordon KB, Lebwohl M, Koo JY, Elmets CA, Korman NJ, Beutner KR, Bhushan R (2008). "Guidelines of care for the management of psoriasis and psoriatic arthritis". Journal of the American Academy of Dermatology. 58 (5): 826–850. doi:10.1016/j.jaad.2008.02.039.
  4. ^ a b c d e f g h i j k l m n o p q r Boehncke WH, Schön MP (September 2015). "Psoriasis". Lancet. 386 (9997): 983–94. doi:10.1016/S0140-6736(14)61909-7. PMID 26025581. S2CID 208793879.
  5. ^ a b c d e f g h i j "Questions and Answers About Psoriasis". National Institute of Arthritis and Musculoskeletal and Skin Diseases. 12 April 2017. Archived from the original on 22 April 2017. Retrieved 22 April 2017.
  6. ^ GBD 2015 Disease and Injury Incidence and Prevalence Collaborators (October 2016). "Global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015". Lancet. 388 (10053): 1545–1602. doi:10.1016/S0140-6736(16)31678-6. PMC 5055577. PMID 27733282.
  7. ^ a b Parisi R, Symmons DP, Griffiths CE, Ashcroft DM (February 2013). "Global epidemiology of psoriasis: a systematic review of incidence and prevalence". The Journal of Investigative Dermatology. 133 (2). Identification and Management of Psoriasis and Associated ComorbidiTy (IMPACT) project team: 377–85. doi:10.1038/jid.2012.339. PMID 23014338.
  8. ^ LeMone P, Burke K, Dwyer T, Levett-Jones T, Moxham L, Reid-Searl K (2015). Medical-Surgical Nursing. Pearson Higher Education AU. p. 454. ISBN 978-1-4860-1440-8. Archived from the original on 14 January 2023. Retrieved 8 May 2020.
  9. ^ Ely JW, Seabury Stone M (March 2010). "The generalized rash: part II. Diagnostic approach". American Family Physician. 81 (6): 735–9. PMID 20229972. Archived from the original on 2 February 2014.
  10. ^ a b Jain S (2012). Dermatology: illustrated study guide and comprehensive board review. Springer. pp. 83–87. ISBN 978-1-4419-0524-6. Archived from the original on 8 September 2017.
  11. ^ Ritchlin C, Fitzgerald I (2007). Psoriatic and Reactive Arthritis: A Companion to Rheumatology (1st ed.). Maryland Heights, MI: Mosby. p. 4. ISBN 978-0-323-03622-1. Archived from the original on 8 January 2017.