What is psoriasis?
Psoriasis is a chronic inflammatory disease that has become one of the most common diseases in Europe. Some form of psoriasis affects about 2-3% of the population and 30-40% of these patients also suffer from psoriatic arthritis, which causes joint problems. The disease is characterized by reddish scaly lesions and spots. Itching may be associated with psoriasis and is mild when it occurs. Psoriasis is equally common amongst men and women and usually first appears between 15 and 40 years of age.

There is no cure for psoriasis; people have to learn to live with the disease. Nevertheless, good treatment options are available that significantly relieves symptoms and makes skin problems disappear for long periods of time for many people. Psoriasis is characterised by flare-ups, which means that the disease periodically varies significantly from mild to severe. The disease is not contagious.

Why individuals are afflicted by psoriasis is not yet completely understood. Psoriasis is viewed as a genetic disease that needs a trigger to break out. Examples of triggers include infection, mental stress or use of certain medications such as lithium, chloroquine or beta blockers.

How does psoriasis affect the body?

If the body is attacked by bacteria or viruses, an inflammation usually serves as a defense mechanism. When suffering from psoriasis, an immune system failure occurs instead, leading to a chronic inflammatory response where the body’s own tissue is damaged.

New skin cells that are formed by the body mature as they are transported through the different layers of the skin. The epidermis is the visible outer layer of the skin. The outer layer of the epidermis is the stratum corneum. This part of the skin consists of dead skin cells that have become hardened and form a barrier to protect the body from bacterial attacks, abrasion and hazardous substances. Under the epidermis lays the dermis. The blood circulation of the dermis helps to regulate the body temperature and supplies both nutrients and oxygen to the outer skin layers.

Our skin is regularly renewed through the formation of new skin cells. The process of forming a new skin cell, transporting it to the epidermis and sloughing it off takes about five to six weeks. The level of scaling that occurs when a skin cell detaches from the skin is minimal since it occurs in such small quantities and over such a long period of time. The immune system failure in the body that occurs during psoriasis mobilizes the white blood cells, our defense cells within the body, to cause chronic inflammation directed against the skin cells. In other words, the white blood cells consider the body’s own cells to be foreign and attack them. This condition is called autoimmunity and results in diseases such as psoriasis and psoriatic arthritis, which are autoimmune diseases. Instead of the usual five to six weeks required for the renewal process, skin cells are replaced about every four days. As a result of this process the skin has insufficient time to mature and thick plaque-like areas of the skin forms instead. Furthermore, there is not enough time for a stratum corneum layer to be formed and therefore skin cells are no longer released one by one, but rather in large pieces, resulting in flaking and peeling. Other symptoms such as redness and heat surrounding the psoriasis lesion are due to the increased blood circulation that results from inflammation. 

Psoriatic arthritis
Psoriatic arthritis is an inflammatory joint disease that affects individuals with psoriasis. About 30-40% of all psoriasis patients also suffer from psoriatic arthritis. This condition has become increasingly common in Scandinavia. However, not much is yet known about this disease. Further research is needed since the factors causing the condition have not yet been fully established. Researchers believe that a combination of external factors and genetics may have the greatest impact.

Both psoriasis and psoriatic arthritis are chronic inflammatory diseases. Inflammation associated with psoriatic arthritis begins in muscle and tendon attachment sites. Once the inflammation reaches the joint arthritis (joint inflammation) develops. Inflammation usually begins in large muscle attachment sites, typically around knees, elbows or over the hip compartments. Large parts of the spine can also be affected. Just as in psoriasis, it is common for psoriatic arthritis to manifest symmetrically, simultaneously affecting both left and right joints.

Symptoms of psoriatic arthritis may vary greatly among individuals. Some affected individuals have mild symptoms that are temporary, affecting only a limited number of joints simultaneously, while others may suffer from aggressive symptoms that culminate in destruction of joints or disability if left untreated.

A number of symptoms may indicate psoriatic arthritis:

  • – Stiffness
  • – Swollen joints
  • – Tenderness
  • – Fatigue
  • – Rest pain and pain with movement
  • – Increased heat in joints

Psoriatic arthritis is a chronic joint disease easily confused with other diseases such as rheumatoid arthritis, osteoarthritis or other rheumatic diseases. The disease is most likely to be misdiagnosed during the early stages. If no or only mild psoriasis symptoms are presented, it may be more difficult to establish that the patient also suffers from psoriatic arthritis. It is therefore important for the doctor to carefully listen to the patients’ history, including the description of symptoms and problems. Currently, psoriatic arthritis cannot be completely cured. It is therefore important to establish a diagnosis and initiate treatment in order to reduce the impact of the disease. Doing so, one can minimise impairment of joint function and destruction of cartilage. As a result, patients can improve their problems in time and control their symptoms, which allows most people to enjoy a good quality of life.  

Quality of life with psoriasis
Psoriasis and psoriatic arthritis are chronic inflammatory diseases for which there is no cure available. Many treatment options for these diseases may suppress the symptoms and to some extent almost completely eliminate symptoms for a long period of time. Nevertheless the symptoms affect the social lives and quality of life for many people. In some cases, patients have had to deal with the disease from an early age. Since psoriasis is characterised by flare-ups, some individuals may require extra support during periods when the disease is at its worst.

To better manage the disease and learn to live with psoriasis, support is available through the Community Health Centre or private doctor as well as through organisations such as the Psoriasis Association. Patients may speak with other individuals who suffer from psoriasis or contact specific organisations that assist young people with psoriasis.   


Site updated 2016-01-12


Psoriasis affects about 2-3% of the population