Psoriasis (psoriasis) - What Is It?

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Psoriasis (psoriasis) - What Is It?
Psoriasis (psoriasis) - What Is It?

Video: Psoriasis (psoriasis) - What Is It?

Video: Psoriasis (psoriasis) - What Is It?
Video: What Is Psoriasis? 2023, September

Psoriasis: what is it?

Psoriasis (psoriasis) is a skin condition that is characterized by inflammation and flaking of the skin. The medical term is derived from the Greek “psao”, in German “scratch”. Psoriasis is based on a hereditary predisposition. Skin symptoms arise when additional trigger factors are added. These include infections, injuries to the skin, stress and certain medications. The disease occurs in various forms and degrees of severity, usually in attacks. The quality of life can be severely impaired, mainly due to pronounced itching and for cosmetic reasons. Symptoms include flaking and reddening of the skin surface.


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  • What causes psoriasis?
  • What forms and symptoms are there?
  • Which comorbidities can occur?

What causes psoriasis?

Psoriasis is based on a malfunction of the immune system, in which the body's own tissue is recognized as foreign and attacked - it is therefore an autoimmune disease. The complex process is associated with pronounced inflammatory processes in the skin. This is accompanied by a thickening of the epidermis and, in sections, defective cornification (parakeratosis) with a loss of the granule cell layer (stratum granulosum). The horn-forming cells (keratinocytes) are swollen and show unusually rapid growth. This results in severe scaling on the surface of the skin.

The exact causes of development are not fully understood. It is believed that several factors play a role. First and foremost, psoriasis appears to be an inherited condition. The genetic share of the psoriasis risk is estimated to be around 60 to 70 percent. A complex interplay of various genetic factors is assumed, the effects of which “add up”.

Hereditary predisposition alone does not mean that psoriasis is inevitable. In order for the disease to break out, further trigger factors (so-called provocation or trigger factors) must become effective. Environmental influences such as infections, smoking, emotional stress and certain medications can cause an outbreak or worsening of an existing psoriasis.

What forms and symptoms are there?

The appearance of psoriasis is extremely diverse, so different forms are distinguished.

Psorasis vulgaris

80 percent of those affected suffer from psoriasis vulgaris. It is also known as plaque-type psoriasis. This form usually begins suddenly as a small patchy rash scattered over the body, often accompanied by itching. The foci (plaques) are very red and initially still scales a little. In most cases, over time, the herd grows very slowly and continuously until they eventually merge. The foci develop very thick, firmly adhering, yellowish to silvery, shiny scales and can become very large.

Psoriasis vulgaris is particularly common in some parts of the body. These so-called predilection sites include the hairy head, extensors of the arms and legs (elbows, kneecaps), back and buttocks. The disease of the navel and between the buttocks (anal fold) is also characteristic. However, other body folds as well as hands and feet can also be affected. Only the mucous membrane remains free of psoriasis. The affected areas often experience itching, a feeling of tightness and dry and cracked skin, often associated with pain.

The disease can appear for the first time at any age, but usually between 15 and 35 years of age. Most of those affected have an episode-like chronic course, with very different variations from one individual to another. Infection of the predilection sites that remains constant over years is just as possible as the skin changes can spread rapidly over large parts of the body surface. The frequency of the attacks is individually variable. In addition, phases of low and high disease activity can alternate over the years. There may be long periods of complete freedom from symptoms between the attacks.

In mild cases, the disease is sometimes only perceived as cosmetically disturbing. In severe cases, the quality of life is often significantly reduced. The disease is currently not curable. Appropriate treatment can significantly reduce skin symptoms and improve the quality of life.

Psoriasis of the scalp

In more than 70 percent of patients with psoriasis vulgaris there are also foci on the hairy head (psoriasis capitis). They can occur locally or over a large area and typically exceed the hairline. The foci are very scaly and reddened. Occasional hair loss usually disappears after successful treatment. Itching is almost always present.

Shampoos with a dandruff-releasing effect serve as basic therapy. If the dandruff is very strong, it can be pre-treated with washable, emulsifying creams or solutions with salicylic acid or oils. Solutions or foams with corticosteroids (if possible without alcohol!) Are the most effective therapy, especially for itching. Supplementary preparations with vitamin D3 derivatives are suitable for long-term use. Patients report good experiences with UV light combs. Before using them, the scales must be eliminated.

Guttate psoriasis

Typical of guttate psoriasis (teardrop-shaped psoriasis) are lenticular, red and slightly flaky changes on the entire surface of the skin. This form often occurs in childhood or adolescence - preferably after infections, especially after streptococcal infections (tonsillitis or scarlet fever). It can also be triggered by drugs such as lithium, beta blockers, ACE inhibitors or chloroquine / hydroxychloroquine. Guttate psoriasis can develop into psoriasis vulgaris, but it can also heal completely.

Psoriasis in the body folds

Those most commonly affected by intertriginous psoriasis

  • Armpits,
  • Skin folds in the groin area (inguinal folds),
  • the skin under the female breast, on the navel and in the anal fold (buttock fold).
  • Belly folds if you are overweight.

With body folds, skin lies against skin, so these areas are usually damp. This allows the scales to peel off easily. Usually only a bright red, shiny hearth is recognizable.

Inverse psoriasis

The skin changes mainly affect the flexion of the large joints (e.g. in the flexor of the knee) without simultaneous disease of the extensor joints. This form is very rare and is associated with serious inflammation.

Pustular psoriasis

A distinction is made between the pustular manifestations of psoriasis:

Generalized forms (affect the entire body surface):

  • Psoriasis pustulosa generalisata: initially isolated, later mostly confluent pustules on the entire surface of the body with fever, severe feeling of illness and swelling of the lymph nodes.
  • Psoriasis cum pustulatione: explosive appearance of pustules in the area of existing foci of psoriasis vulgaris (if it worsens acutely).

Localized forms are limited to certain areas of the body:

  • Pustulosis palmoplantaris (PPP): In this genetically independent disease, pustules develop on the palms of the hands and / or the soles of the feet, some of which are lacunae-like. If the area is large and there are many fresh yellow pustules, the disease is painful and significantly restricts walking or grasping. The relapse rate of the disease is very high. Smoking can have negative effects.
  • Acrodermatitis continua suppurativa (Hallopeau): In this very rare disease, so-called pustular lakes with severe inflammation develop on the tips of the extremities (acral), which quickly leads to the loss of the nail and the nail matrix. The bones of the finger and toe joints can be destroyed in the course of the disease.

Psoriasis of the nails

In many patients with psoriasis, the fingernails and / or toenails are more or less noticeably changed. A disease of the nails with simultaneous psoriatic arthritis is even more common. As a rule, several nails on both hands and feet are affected at the same time.

There are different changes to the nails: the nail thickens and forms scars on its surface so that it resembles a thimble. In many cases the nail can easily be detached from the finger or toe. In addition, the cuticle can thicken, cracks can appear lengthways and lines crosswise. There is also discoloration with yellowish or salmon-colored areas. Sometimes the nails take on a whitish or opaque color. The nail can become brittle or crumbly. The nails can fall off or be destroyed. The inflammation can also spread under the nail bed, making the lesions out of air and difficult to heal.

Psoriatic erythoderma

The entire skin is diseased, reddened by inflammation and mostly shows rather fine, loose flaking. Erythoderma is the rarest and at the same time the most severe form of psoriasis vulgaris. Often there is severe itching. The patients feel very ill, have a fever, are exhausted, complain of weight loss and painful joints. The lymph nodes are swollen.

Which comorbidities can occur?

Psoriasis is a systemic - that is, affecting the entire organism - disease. It includes skin symptoms, possible joint involvement (psoriatic arthritis) and characteristic accompanying diseases (comorbidities). These include other chronic inflammatory diseases with possibly overlapping disease mechanisms, especially:

  • Musculoskeletal system: Rheumatoid arthritis (about four times more common).
  • Digestive tract: Inflammatory bowel disease (IBD; about two times more common).
  • Metabolism: Metabolic changes such as lipid metabolism disorders, diabetes tendency and obesity.
  • Cardiovascular system: An increased risk of high blood pressure and cardiovascular diseases such as myocardial infarction and stroke as well as increased mortality with a life expectancy reduced by three to four years is assumed, especially for younger patients with severe psoriasis.
  • Mental health : It may also be associated with certain mental disorders, including affect disorders and depression.