Symptoms and causes

Symptoms and causes

What is it?

Psoriasis is a common skin condition that typically results in sharply delineated, white flaking patches with a red background that are often itchy and sometimes painful. The spots can occur anywhere on the body. The preferred locations are the elbows and knees, the lower back and the scalp. The nails can also be affected, sometimes there are joint complaints.

How often does it occur?

Approximately 300,000 people in Belgium suffer from this disease. The condition is not contagious.


The cause of psoriasis is a disorder in the skin growth: our skin constantly renews itself, normally the old skin cells flake off and are replaced by new ones. In psoriasis, the production of skin cells is accelerated and the upper skin layer will not get rid of the old skin cells quickly enough. This results in thicker skin spots.

Psoriasis is a genetic autoimmune disease and is a chronic disorder. This means that the condition cannot be completely cured, but treatments with ointments, light therapy or medicines (tablets or injections) can keep skin lesions and symptoms under control. Some factors such as infections, skin damage and medication can adversely affect psoriasis and cause an upsurge in skin lesions.

Sooner or later, joint symptoms may also occur in 5-30% of patients with psoriasis. If the dermatologist considers the symptoms to be corresponding to psoriasis arthritis (this is psoriasis of the joints) an evaluation by the rheumatologist will be offered.

Diagnosis and treatment

Diagnosis and treatment

Various treatments for psoriasis are available. These do not cure the skin disease, but make it manageable. Depending on the extent of the skin lesions, the burden (such as itching or pain) experienced, any other conditions the patient has (had) and the patient's wishes, a customised treatment will be chosen.

In the treatment of psoriasis we roughly distinguish three types of treatment:.

1. Local treatment with ointments, creams and lotions:

Corticosteroid creams, vitamin D creams and tar ointments can be used for this purpose. Sometimes, a local remedy containing salicylic acid or urea is used to loosen the thick flakes.

2. light therapy (UVB of PUVA):

The effect of light therapy in psoriasis is based on the local suppression of the inflammatory reaction by means of exposure to UVB or PUVA.

3. Medication:

There are various medications that can have a beneficial effect on psoriasis. These are effective because they block a protein that plays a role in the inflammatory cascade and can thus stop the inflammation.

  • Tablets or small molecules (methotrexate, acitretin, cyclosporine, fumarates) are medications in pill form.
  • Injections (biologicals)

Various injections (or biologicals) are available. The dermatologist will discuss the pros and cons of the drugs with you during the consultation. In order to be reimbursed for this medication, you must meet various conditions. For example, you must have already undergone various treatments such as light therapy, ledertrexate and cyclosporine. Before starting a biological, an X-ray of the lungs is taken and a puncture test is done on the forearm to exclude tuberculosis.

Starting up a biological requires some supervision and a good follow-up. For this, we work together with our IMID nurse Inge Huys. Over time, you can give the injections yourself, a nurse or a GP. The dermatologist, GP and the reference nurse monitor everything.

Psoriasis, with or without treatment, often has a variable course in which bumps and quiet periods alternate.

  • Emotional stress seems to play a role. This is why relaxation has a beneficial effect on skin disease.
  • A healthy, varied diet and sufficient exercise also have a beneficial effect.
  • In general, it is beneficial to keep the skin moisturised, which makes it easier for flakes to come off and for external cream treatments to penetrate.
  • Regular rubbing of the skin also reduces itching. This reduces scratching, scratching or injury can cause a new psoriasis lesion at the site of the skin damage.

Treatment centres and specialisations

Treatment centres and specialisations

Latest publication date: 14/12/2022
Supervising author: Dr Van Autryve Els