Psoriasis

Psoriasis is a skin disease that causes a rash that is usually distributed in spots on the body. It is assumed that 2-3% of the population has psoriasis. The cause of psoriasis is not known, but heredity is important. In addition to medical treatment, there are measures you can take yourself to make the rash go away and help keep the disease at bay.

What is psoriasis?

Psoriasis is a common skin disease that causes a rash covered in whitish, scaly crusts. The rash is caused by a chronic inflammatory reaction in the skin. Elbows, knees, back and scalp are most often affected, but psoriasis can also occur elsewhere on the body.

It is believed that psoriasis is caused by an immune reaction directed at parts of the skin, which causes the cells in the outermost skin layer to divide faster than normal and the skin therefore thickens.

Causes of psoriasis

The cause of psoriasis is unknown, but it is known that heredity is important. Half of all people with psoriasis have someone in their family who also has the disease. Psoriasis is not contagious.

Psoriasis can be triggered or worsened by several factors:

• Infections, such as streptococcal infection (strep throat)

• Use of medicines, such as certain blood pressure medicines (beta blockers), lithium and the antimalarial medicine chloroquine

• Great mental strain and stress

Types of psoriasis and symptoms

• The most common form of psoriasis is plaque psoriasis (psoriasis vulgaris), which produces characteristic red and scaly rashes in limited areas. Plaque psoriasis usually begins with small spots that gradually grow and are eventually covered by a silver-white, scaly crust. The rash can appear on most areas of the body, and the most common areas are the knees and elbows.

• If you have plaque psoriasis, you may also experience scalp psoriasis. Scalp psoriasis is most frequently seen around the hairline, on the neck, behind the ears or in the temple, and often extends a couple of centimeters beyond the hairline. The skin may feel tight and itchy, and some people experience temporary hair loss in areas of the scalp.

• Psoriasis on the nails is also experienced by many who have plaque psoriasis, especially with psoriatic arthritis. The symptoms of nail psoriasis can vary in severity, and can be confused with nail fungus. The nail often becomes thickened, discolored and uneven. Some also experience that the outermost part of the nail lifts from the skin underneath.

• Guttate psoriasis, also called "drop psoriasis" is the second most common form of psoriasis. The rash has a characteristic teardrop shape and is typically seen on areas such as the chest, abdomen, thighs and upper arms. This form is most common in children and young adults, and often occurs as a result of a streptococcal infection in the throat. The course of guttate psoriasis is usually easier than that of plaque psoriasis, and most people with guttate psoriasis get rid of the rash only with short-term treatment. However, the rash may return on later occasions, but preferably in a milder form.

• Inverse psoriasis (skin against skin) is psoriasis in skin folds, such as in the armpits, under the breasts, in the groin or in the abdomen. The rash is red and often sharply demarcated from the surrounding skin, but is not typically scaly.

• Psoriatic arthritis is a type of psoriasis that does not attack the skin, but the body's joints. This is therefore a form of arthritis. Psoriatic arthritis most often occurs in people who also have severe skin symptoms

• More rarely is having psoriasis over large parts or the whole body, erythroderm psoriasis. This is the most severe form of psoriasis, and is often triggered by medication.