Typical signs are reddish, flaky skin lesions and severe itching. Psoriasis is almost always a chronic condition with episodic flare-ups. The symptoms can be alleviated with various treatments.

At a glance

  • Psoriasis is an inflammatory, non-contagious condition.
  • Typical symptoms are reddish, flaky skin lesions, often with severe itching.
  • Psoriasis can affect other parts of the body as well as the skin.
  • A cure has not yet been discovered for psoriasis.
  • There are various treatments that can be used to alleviate the symptoms.

Note: The information in this article cannot and should not replace a medical consultation and must not be used for self-diagnosis or treatment.

Psoriasis: man bending his arms next to his upper body and showing his elbows. There is psoriasis on both elbows.

What are the symptoms of psoriasis?

There are different types of psoriasis. The most common form is plaque psoriasis (psoriasis vulgaris).

Plaque psoriasis

In this form of psoriasis the skin reddens and slightly raised lesions covered in silver scales form. These raised lesions are called plaques. They are well-defined and tend to flake off. Plaques often occur at the same place on both sides of the body, for example the left and right elbows. The skin affected is frequently itchy, particularly during a flare-up or if someone has a more severe form of psoriasis. The skin is often additionally irritated by scratching and may become injured.

Plaques differ considerably in size. On average they measure between one and over ten centimeters across. Some people only have a few plaques on single areas of the body, for example only on their scalp. But others have large numbers of plaques on one or more parts of the body.

Plaque psoriasis can affect any part of the body. It particularly affects the head, elbows, knees and back. But plaques also often occur behind the ears, on hands and feet or on the navel.

The skin on hands and feet may also become very dry and crack. This can be very painful. It becomes particularly unpleasant if the cracked skin stretches during motion, comes into contact with irritants such as fruit acid, or becomes bruised.

Another form of plaque psoriasis is nail psoriasis. This causes the nails to develop small dents or pits, become thicker or become brownish-yellow. The nail may also become detached.

Eine junge Frau hält eine Tube mit Salbe in einer Hand. Sie trägt etwas Salbe auf eine gerötete und leicht schuppige Hautstelle an der anderen Hand auf.

Other forms of psoriasis

Psoriasis sometimes affects folds or creases in the skin, in which case it is referred to as inverse or intertriginous psoriasis (psoriasis inversa or psoriasis intertriginosa). This affects creases in the skin such as the groin, between the buttocks, under the armpits, in the genital region or under and between the breasts in women. Plaques or flakes do not usually appear since the skin in these areas is relatively damp and constantly exposed to friction.

Another form is pustular psoriasis (psoriasis pustulosa). This causes pus-filled blisters (pustules). These pustules are not contagious. Pustular psoriasis may occur on its own or in conjunction with a form of plaque psoriasis.

Guttate psoriasis (psoriasis guttata) is a relatively rare form of psoriasis. It mostly affects children and adolescents. It typically causes an acute rash with small pimples (papules) across large portions of the body. It mostly occurs 1 to 2 weeks after a streptococcal infection and may heal completely after some weeks or months. However it may also recur or turn into a plaque psoriasis.

What is psoriasis?

Psoriasis is a chronic inflammatory, non-contagious skin condition. It is characterized by reddened, flaky skin that sometimes itches.

Psoriasis can take many different forms. It usually progresses episodically with sometimes severe, sometimes mild symptoms and even sometimes no problems at all. Some people find the skin condition distressing whilst others cope with it fairly well. Some people find it has a severe impact on the quality of life since both treatment and skin care can be cumbersome and time-consuming. Psoriasis also causes many people mental distress due to the often visible reddish, flaky skin lesions.

Other parts of the body may be affected as well as the skin, such as the joints or nails.

There are various treatments that can be used to alleviate the symptoms. There is no cure for psoriasis as yet.

What causes psoriasis?

The top layer of the skin (the epidermis) consists of keratogenic skin cells (keratocytes). These keratocytes divide and get pushed up to the surface of the skin where they die and form dead skin cells known as corneocytes.

It normally takes about 4 weeks for the keratocytes to move through the epidermis before being shed as dead skin cells. In people with psoriasis, however, it can take just 4 days, with the cells dividing almost ten times more quickly. That means the dead cells aren’t shed quickly enough. The skin becomes thicker at the places affected and starts to flake much more than usual.

This is because of autoimmune responses. An overactive immune system releases more chemical messengers (cytokines) that cause an inflammatory response. Some of the chemical messengers also prompt the keratinocytes to reproduce more rapidly. Inflammation and stronger circulation often cause the skin to become red.

What is autoimmune disease?

The video below provides basic information on the human immune system and typical autoimmune diseases.

This and other videos can also be found on YouTube

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What are the risk factors for psoriasis?

Certain types of genetic predisposition play a role in psoriasis and are the greatest risk factor.

If one parent has psoriasis there is a 15% likelihood of the child having it too. If both parents have psoriasis the risk of the child having it is around 40%. There is no reliable test to predict whether someone will develop psoriasis. Nor is there any way to prevent it according to the current state of scientific knowledge.

How common is psoriasis?

Psoriasis is a relatively common condition. Approximately 2% of the population have psoriasis. That converts to over 1.5 million people in Germany. The prevalence is the same for men and women.

Approximately 1.5 million people in Germany have psoriasis.

Psoriasis often occurs before the age of 40. It frequently starts in childhood or young adulthood. If it develops later on it is mostly between the ages of 50 and 70.

Psoriasis is also sometimes categorized by age of first onset: type 1 begins before age 40, and type 2 starts at age 50 to 70.

How does psoriasis develop?

It is not possible to predict how psoriasis will develop. The condition usually progresses episodically, alternating between phases of more severe symptoms and phases with little to no problems at all. But there are also people who have severe psoriasis on a permanent basis.

Certain factors can trigger episodes of psoriasis. These stimuli include sunburn, showering in water that is too hot, certain chemicals or minor skin injuries from scratches, tattoos or piercings.

Psychological stress, infections and nicotine or excessive alcohol consumption can also make an episode more likely. Some types of medication such as certain antimalarial drugs are suspected of being capable of triggering a flare-up of psoriasis.

Important: Psoriasis is an inflammatory autoimmune disease. It can affect other parts of the body as well as the skin. It also causes inflammation of joints in approximately 25% of patients. This form is known as psoriatic arthritis. People who are suspected of having psoriatic arthritis should seek medical advice since early detection of arthritis allows it to be treated better. This also helps to avoid damage to the joints.

Psoriasis can be psychologically stressful, sometimes to such an extent that it causes depression or an anxiety disorder. In these cases it may be useful to have this condition treated as well, perhaps through psychotherapy.

Studies show that people with psoriasis are more likely to have cardiovascular diseases. There are various explanations for this: for example, people with psoriasis are more likely to be overweight and have high blood pressure, diabetes or unhealthy cholesterol levels. Their autoimmune responses may also be a factor.

People with psoriasis are also more likely to develop chronically inflamed intestinal diseases such as Crohn’s disease or ulcerative colitis.

How is psoriasis diagnosed?

Dermatologists normally diagnose psoriasis based on its typical skin lesions. If there is any doubt, examining a small skin sample can provide clarity. In the case of psoriasis inversa, for example, this can be particularly helpful: this type only forms in skin folds and usually does not involve scales. Therefore it is sometimes mistaken for a fungal infection.

Nail psoriasis is also sometimes mistaken for a fungal nail infection. However the two conditions may occur simultaneously. Examination of a nail sample reveals whether the nail is infected by fungi.

The examination also includes an assessment of the severity of the psoriasis. This will depend on various factors including how much skin is affected:

  • in severe forms more than 10% is affected;
  • in moderate forms 5 to 10%;
  • in mild forms less than 5%.

Medical practitioners also classify psoriasis as moderate or severe if it affects the head, hands, nails, feet or sensitive parts of the body such as the genitals, or a person’s quality of life is severely impaired.

How is psoriasis treated?

Psoriasis cannot be cured. However, there are various ways to treat it:

Skincare (maintenance therapy)

This involves caring for the parts of the skin affected by psoriasis with lipid replenishing ointment, cream or lotion. Good skincare is also recommended for periods with no skin problems.

Medicinal creams

Anti-inflammatory creams containing cortisone, or vitamin D3 analogs are normally used for topical therapy (externally). This is sufficient in most cases of mild psoriasis.

Further information, for instance on topical treatment of psoriasis, can be found at

Light therapy

Here, the plaques are exposed to ultraviolet light (UV light). The UV light inhibits inflammation in the skin and slows down cell division. It is sometimes used in combination with psoralen products, drugs that make the skin more sensitive to light. This form of therapy is suitable for people with moderate or severe psoriasis where topical treatment alone doesn’t provide enough help.

There are a number of options for treating psoriasis: skin care, medicinal creams, UV light therapy, oral medication and injectable drugs.

Oral medications and injections

These drugs inhibit the immune response. They include methotrexate (MTX), fumaric acid esters, apremilast, ciclosporin and biologics (biological treatments). They are suitable for people with moderate or severe psoriasis.

There is no evidence of other treatments being effective for psoriasis. This also applies to plant-based products such as those made from Oregon grape (Mahonia aquifolium), birch bark or aloe vera, as well as food supplements containing fish oil or omega 3 fatty acids. These are therefore not recommended by professional medical associations for treatment of psoriasis.

Some studies suggest that psoriasis improves when people with obesity lose weight.

Important: Some claim that psoriasis symptoms can be alleviated by removing the tonsils. However there are no studies proving that psoriasis can be healed or prevented by this type of surgery. 

What is life like with psoriasis?

Psoriasis is a condition that many people find very distressing. The cumbersome skincare routine, as well as coordinating treatments with everyday obligations, job, family and free time can be very challenging. The fact that the itching tends to be at its worst in the night-time means that people with psoriasis do not get much sleep, frequently leaving them tired and exhausted during the day.

Despite the fact that psoriasis is relatively widespread, people find they are often being avoided by others. Some people mistakenly think the skin condition is contagious. This can quickly turn everyday activities such as going for a hair cut into an unpleasant experience. Anxiety about how other people might react can reduce quality of life. It also makes some people with psoriasis withdraw from society.

Many people find it helpful to talk to people who have had similar experiences to them. They can talk to them about feelings, experiences and practical problems that people without psoriasis find hard to understand.

The website has reports from four people with experience of psoriasis.

Where can I find support?

Self-help groups offer people with psoriasis and their loved ones a way of obtaining information and advice, and sharing personal experiences.

You can find suitable self-help via a database on the National Contact and Information Point For Encouraging and Supporting Self-Help Groups (NAKOS) website.

In cooperation with the Institute for Quality and Efficiency in Health Care (Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen) (IQWiG).

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