The main causes of psoriasis are heredity, infection, immunity and environmental factors.
Common types are mainly as follows:
1. Psoriasis vulgaris, features of skin lesions: scalp, trunk and limbs, especially elbows and knees, are prone to extend, and can also be widely and symmetrically distributed throughout the body. Itching varies in severity.
At first, it was red papules or maculopapules, and gradually merged into patches, and the surface was covered with many layers of silvery white scales. In the later stage, it is a red patch covered with a thick layer of silvery white scales. When scraping scales, there will be the feeling of scraping wax drops on the table (wax drop phenomenon), and then scraping off the translucent reddish film with bright film (film phenomenon), scraping off the film with small bleeding points (triad).
Damage to scalp: ① Clear boundary ② Thick scales ③ Bundle hair.
Damage to nails: In light cases, thimble-like depressions can be seen on the deck. In severe cases, it is dull, horizontal groove, hypertrophy, nail peeling, deformity or absence.
The disease can be divided into three stages: ① Progressive stage: new rashes appear constantly, old rashes expand constantly, scales thicken, inflammation is obvious, itching is obvious, skin sensitivity increases, and homomorphic reactions may occur (new rashes occur at the trauma). ② Resting period: No new rash, but the old rash persists and the condition is stable. ③ regression period: inflammation subsided, scales decreased, rash narrowed and flattened, light-colored halo appeared around, and finally temporary hypopigmentation or calmness was left, which was clinically cured, and some people also appeared pigmentation.
2. Articular psoriasis, course characteristics: the course is slow and difficult to cure. It is more common in men, often secondary to repeated deterioration of psoriasis, and most of them are complicated with other types.
Characteristics of skin lesions: asymmetric peripheral polyarthritis, especially in the small joints of hands, wrists and feet, may have systemic symptoms.
In addition to the rash, it is accompanied by joint lesions. When the rash is aggravated, the joint lesions are also aggravated. In severe cases, large joints (such as knee, ankle, shoulder, epiphysis and spine) can also be involved, and the joints are red, swollen and painful, with limited function and even joint deformity. Patients are often accompanied by fever, anemia, hepatosplenomegaly and lymphadenopathy.
3.? Erythrodermic psoriasis, course characteristics: It is a rare severe psoriasis. The course of disease is long and easy to recur. Most of them are induced by improper treatment, especially psoriasis vulgaris in acute progressive treatment, the use of highly irritating external drugs, or the sudden withdrawal or rapid reduction of glucocorticoid after long-term use.
Characteristics of skin lesions: diffuse flushing, swelling and infiltration of the whole body skin, with a large number of scales on the surface, during which island-like normal skin can be seen. Punctate bleeding can disappear, patients are often accompanied by fever, superficial lymphadenopathy and other systemic symptoms, and the granulocyte count is often increased.
4. Pustular psoriasis,
(a), generalized: rare, serious. Most of them appear after improper treatment of common type.
Characteristics of the course of disease, sudden onset, accompanied by systemic symptoms.
Characteristics of skin lesions: erythema occurs suddenly on the basis of psoriasis vulgaris, or on normal skin, and groups of yellow-white sterile superficial pustules with the size of needle tip to rice grain appear rapidly on the surface, and pustules can merge into pus lakes with the diameter of 1~2cm, and appear in batches, and groups of yellow-white sterile superficial pustules with the size of needle tip to rice grain appear rapidly on the surface, and pustules can merge into pus lakes with the diameter of 1~2cm.
(2) Limitations:
① Palmoplantar pustulosis: It can be divided into palmoplantar pustulosis and continuous acrodermatitis. Palmoplantar pustulosis: It often occurs in palmoplantar toes (fingers) and is symmetrically distributed. It is characterized by sterile pustules of needle to millet size on the basis of erythema, which dry up and scab and desquamate in about 1~2 weeks, and grow new small pustules after desquamation. Periodic, sometimes light and sometimes heavy, slow course of disease, stubborn and refractory; Decks can be pitted, thickened, peeled off and longitudinal ridges.
② Continuous acrodermatitis: rare. It often occurs at the toe (finger) end. Scales and scabs can be seen after the pustules subside. The nail bed may also have pustules, and the deck may fall off.