Causes of Psoriasis


Even though psoriasis is just a minor inflammation for some people, it can have a serious impact on the quality of life for those more badly affected. For instance, some people with psoriasis have low self-esteem because of the effect the condition has on their looks.1

Psoriasis, like other chronic diseases, can have an impact on areas of your life other than your physical health. Psoriasis can have an impact on your emotional health, relationships, and stress management. Living with psoriasis can be difficult for some people. But, there are ways to deal with those problems and thrive with psoriasis.2

What is psoriasis?

Psoriasis is an autoimmune condition that creates inflammation in your skin. Symptoms of psoriasis consist of thick areas of discoloured skin covered with scales. These scaly, thick areas are called plaques.

Psoriasis is a recurring skin condition, which means it can flare up suddenly and there is no cure.4

Psoriasis affects around 2 in 100 people in the UK. It can outset at any age, but most regularly occurs in adults between 20 and 30 years old and between 50 and 60 years old. It affects women and men equally.

The harshness of psoriasis differs greatly from person to person. For some, it's just a small irritation, but for others, it can have a huge impact on their quality of life.

Psoriasis is a long-lasting (chronic) disease that usually involves periods when you have no symptoms or mild symptoms, followed by periods when symptoms are more severe.1


Typical signs and symptoms of psoriasis consist of:

  1. A patchy rash that differs widely in how it looks from individual to individual, ranging from spots of dandruff-like scaling to extensive eruptions over much of the body
  2. Rashes that alter in colour, tending to be tones of purple with a grey scale on brown, or black skin and pink, or red with the silver scale on white skin
  3. Tiny scaling spots (commonly seen in children)
  4. Cracked, dry skin that can bleed
  5. Burning, itching or soreness
  6. Recurrent rashes that flare for a few weeks or months and then ease of

There are various types of psoriasis, each of which differs in its signs and symptoms:

  1. Plaque psoriasis: This is the most common type of psoriasis, it causes itchy, dry raised skin patches covered with scales. There may be several or many. They usually appear on the knees, elbows, lower back and scalp. The patches differ in colour, depending on skin colour. The affected skin could heal with momentary changes in colour (post-inflammatory hyperpigmentation), particularly on black or brown skin
  2. Nail psoriasis: This can affect toenails and fingernails, causing pitting, atypical nail growth and discolouration. Psoriatic nails might unbind and separate from the nail bed (onycholysis). Serious disease may cause the nail to crumble
  3. Guttate psoriasis: It primarily affects adolescents and children. It is typically caused by a bacterial infection, such as strep throat. Drop-shaped, little scaling patches on the arms, legs, or torso indicate it
  4. Inverse psoriasis: It primarily affects the skin folds of the groyne, breasts and bottom. It causes smooth patches of inflamed skin that worsen with sweating and friction. Fungal infections may trigger this type of psoriasis
  5. Pustular psoriasis: it is a rare type, which causes clearly defined pus-filled blisters. It can appear in widespread patches or on small areas of the soles or palms
  6. Erythrodermic psoriasis: the least prevailing type of psoriasis, it can cover the whole body with a peeling rash that can burn or itch intensely. It can be acute (short-lived) or chronic(long-term)3

Psoriasis as an autoimmune condition


Autoimmunity is the presence of antibodies (which are made by B lymphocytes) and T lymphocytes aimed against normal components of a human (autoantigens). These elements are called self-antigens or autoantigens and typically consist of proteins. The antibodies and T lymphocytes that identify autoantigens are called "autoreactive T cells" and "autoantibodies".5

Autoreactive T cells

The autoreactive area contains at least two types of cells: self-reactive cells, which are regulated during development to moderate the immune response as part of a small tolerance mechanism, and autoreactive cells, which can be harmful and cause autoimmunity. In this manner, autoreactive T-cells are easily detectable in healthy individuals, but they are efficiently controlled by peripheral resistance. When the tolerance is broken, autoreactive T-cells may become activated and generate apparent autoimmunity. The awakening of autoreactive T-lymphocytes is a key event in almost any autoimmune response.6

Rapid skin cell production

In a month, normal skin cells grow and shed entirely with psoriasis, skin cells do this in barely three or four days. Contrary to shedding, the skin cells accumulate on the surface of the skin. 2

Excess cells pile up under the skin’s surface

When you have psoriasis, your immune system is presumed to destroy foreign invaders, like bacteria, to keep you in good condition and prevent you from getting sick. Instead, your immune system may mistake healthy cells for foreign intruders. Accordingly, your immune system initiates inflammation or swelling, which you see on the surface of your skin as skin plaques.4


Psoriasis is a common, lifelong disease with no cure. It can be agonising, interfere with sleep and make it difficult to concentrate. This condition tends to go through phases, flaring for a few weeks or months, then easing off for a while. 

There are treatments available to help you handle the symptoms. Additionally, you can try lifestyle habits and coping strategies to help you improve your life with psoriasis. While scientists do not know what in particular causes psoriasis, we do know that the immune system and genetics play important roles in its development We do know that psoriasis is not communicable and that you cannot catch it from another person. In most cases, something causes psoriasis, causing symptoms to appear or diminish.2


  1. Psoriasis [Internet]. 2017. Available from:
  2. Psoriasis: causes, triggers and treatments [Internet]. 2022. Available from:
  3. Psoriasis - Symptoms and causes [Internet]. Mayo Clinic. 2022. Available from:
  4. Psoriasis: what it is, symptoms, causes, types & treatment [Internet]. Cleveland Clinic. 2022. Available from:
  5. Definition of autoimmunity & autoimmune disease - autoimmune disease | johns hopkins pathology [Internet]. Available from:
  6. Boehncke WH, Brembilla NC. Autoreactive t-lymphocytes in inflammatory skin diseases. Front Immunol [Internet]. 2019 May 29;10. Available from:

Anna Mizerska

Masters in Global Health and Biomedical Engineer
Anna is a highly analytical and insightful professional with progressive experience in providing quality services in fast-paced and high-pressure environments. Over the years she has built up extensive knowledge, expertise and transferable skills that translate into writing reliable medical content and articles. presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
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