The most typical symptom of psoriasis is generalized or localized erythema, manifested by thick silvery-white scales, also known as psoriasis. There are four types of psoriasis based on clinical symptoms: the common, arthritic, pustular and erythrodermic types. The most common type is the common type, which is manifested as red plaques with clear boundaries of different shapes, which can be dotted, plaque, map, coin or oyster-like and covered with thick layers of silvery-white scales. When the scales are scraped off, it can be seen that the scales are in layers and there is a translucent film on the surface, and dotted bleeding can be seen when the film is scraped off. This is the so-called psoriasis triad. The latter three types are subtyped on the basis of the typical rash with arthralgia, pustular changes, and erythrodermic changes, with differences in treatment. In addition, there are many patients who present with only a limited rash on the frontal hair junction of the scalp, or on the penis, which can easily be misdiagnosed as seborrheic dermatitis or tinea capitis, etc. The scaling of psoriasis is characteristic and is not difficult to diagnose. The main thing is that the treatment is easy to repeat. If you suspect this disease, you should establish the correct treatment concept after diagnosis, control the symptoms mainly, use more moisturizers to increase the protection of the skin, live with less colds, do not drink alcohol, do not eat spicy stimuli, and do not overexert yourself to reduce recurrence.