Psoriasis, commonly known as psoriasis vulgaris, is a disease that may be related to reduced immunity, genetic factors, and recurrent tonsillitis. Some patients also have a history of trauma. After the onset of the disease, if the symptoms are mild and there is itching, it is permissible to scratch, but the force should be gentle to avoid creating scratches or further injuries on the skin. Otherwise, psoriasis can spread and worsen along these scratches or injuries, a phenomenon known as the Koebner response. If there are many lesions on the body, try to avoid scratching as it can exacerbate the symptoms. Once diagnosed with this disease, it is essential to seek standardized and formal treatment, which generally involves oral medications combined with topical treatments, and the use of narrow-band ultraviolet light therapy, which can be effective.