Psoriasis is a chronic skin disease whose cause is currently unknown and that evolves in spurts. It appears on parts of the skin, which becomes red and scabbed with "scales", a kind of unsightly white film layer. These skin lesions can be itchy and painful. There are several types of psoriasis according to the morphology of the plaque: guttate, pustular, erythrodermic or reversed. The disease affects both men and women and usually occurs in young adults. Psoriasis can be benign and limited to the nails, elbows, knees, feet, hands or scalp, but it can be more severe and spread throughout the body.
Psoriasis in its characteristic form occurs as follows:
- red spots covered with a whitish film;
- often in knees, elbows, scalp, nails, lower back.
Other forms affect only the nails or scalp, or can be generalized throughout the body which is the case of erythrodermic psoriasis. Sometimes lesions called pustules are present, hence the term pustular psoriasis.
The diagnosis of psoriasis is made by the observation of lesions described above, and no further investigation is required to identify it.
Currently there is no cure for psoriasis, given its still unknown origin. However, treatments are used to limit the effects and severity of relapses. Local treatment of applying a cream containing corticosteroids is frequently used in the form of skin ointments, special creams for areas like the folds, or lotions for the scalp. In addition, a derivative of vitamin D, such as calcitriol, may also be prescribed. Other techniques exist to treat the effects of psoriasis such as phototherapy
, which involves sessions of exposure to ultra-violet ray over the course of several sessions per week. In some cases, other molecules, such as methotrexate, cyclosporine or retinoids, derivatives of vitamin A, may be prescribed.