Diagnosis

The diagnosis of psoriasis is made on the basis of the physical examination and some tests on the affected skin area. Thus, there are some phenomena that are typical of psoriasis and mark it. First of all, the candle phenomenon should be mentioned.

If one scratches with a wooden spatula over the thickened, conspicuous skin area, layers of skin peel off and leave the optical impression of a pulverized candle wax. The more layers one scrapes off in this way, the thinner the skin plate becomes. At the bottom of this skin plate you will find a thin membrane, which is also very typical for psoriasis and is also called “the last membrane”.

If you scratch it, small sections of this membrane open up and a spotty bleeding occurs. This bleeding is the third characteristic of psoriasis and is called the prying out phenomenon. With these three characteristics, which can be done with a simple examination of the skin, psoriasis has been proven.

Some other laboratory tests, which are not part of a standardized initial diagnosis of psoriasis, can also be performed. They would show some autoantibodies that are highly elevated and would confirm the suspected diagnosis of psoriasis. Inflammatory values, such as CRP or leukocytes, may also be elevated in an acute episode of psoriasis.

Symptoms of psoriasis of the scalp

The first symptoms of psoriasis are reddish skin changes on the scalp. Usually only small areas are affected at first, but these can increase in size over time. The redness of the scalp is also associated with moderate to severe itching.

The affected persons usually start scratching the scalp, which already peels off the first layers of skin. The classic skin symptom of psoriasis of the scalp is a thickening of the skin due to the rapid transport of skin cells to the skin surface. Thus, in addition to the reddening and itching of the skin, a thickening of the skin occurs relatively quickly.

This can result in a skin plate on the scalp that is several millimeters thick.If the patients scratch because of the itching, layers of skin peel off and leave a candle-wax-like image on the skin. Also characteristic for psoriasis is an explosive spread of redness and scaly skin areas. Thus, within a few days the scalp, arms and/or back can be completely affected. Untreated, these skin areas remain for several days to weeks.